How to Convince Someone When Facts Fail

Why worldview threats undermine evidence

Have you ever noticed that when you present people with facts that are contrary to their deepest held beliefs they always change their minds? Me neither. In fact, people seem to double down on their beliefs in the teeth of overwhelming evidence against them. The reason is related to the worldview perceived to be under threat by the conflicting data.

Creationists, for example, dispute the evidence for evolution in fossils and DNA because they are concerned about secular forces encroaching on religious faith. Anti-vaxxers distrust big pharma and think that money corrupts medicine, which leads them to believe that vaccines cause autism despite the inconvenient truth that the one and only study claiming such a link was retracted and its lead author accused of fraud. The 9/11 truthers focus on minutiae like the melting point of steel in the World Trade Center buildings that caused their collapse because they think the government lies and conducts “false flag” operations to create a New World Order. Climate deniers study tree rings, ice cores and the ppm of greenhouse gases because they are passionate about freedom, especially that of markets and industries to operate unencumbered by restrictive government regulations. Obama birthers desperately dissected the president’s long-form birth certificate in search of fraud because they believe that the nation’s first African-American president is a socialist bent on destroying the country.

In these examples, proponents’ deepest held worldviews were perceived to be threatened by skeptics, making facts the enemy to be slayed. This power of belief over evidence is the result of two factors: cognitive dissonance and the backfire effect. In the classic 1956 book When Prophecy Fails, psychologist Leon Festinger and his co-authors described what happened to a UFO cult when the mother ship failed to arrive at the appointed time. Instead of admitting error, “members of the group sought frantically to convince the world of their beliefs,” and they made “a series of desperate attempts to erase their rankling dissonance by making prediction after prediction in the hope that one would come true.” Festinger called this cognitive dissonance, or the uncomfortable tension that comes from holding two conflicting thoughts simultaneously.

Two social psychologists, Carol Tavris and Elliot Aronson (a former student of Festinger), in their 2007 book Mistakes Were Made (But Not by Me) document thousands of experiments demonstrating how people spin-doctor facts to fit preconceived beliefs to reduce dissonance. Their metaphor of the “pyramid of choice” places two individuals side by side at the apex of the pyramid and shows how quickly they diverge and end up at the bottom opposite corners of the base as they each stake out a position to defend.

In a series of experiments by Dartmouth College professor Brendan Nyhan and University of Exeter professor Jason Reifler, the researchers identify a related factor they call the backfire effect “in which corrections actually increase misperceptions among the group in question.” Why? “Because it threatens their worldview or self-concept.” For example, subjects were given fake newspaper articles that confirmed widespread misconceptions, such as that there were weapons of mass destruction in Iraq. When subjects were then given a corrective article that WMD were never found, liberals who opposed the war accepted the new article and rejected the old, whereas conservatives who supported the war did the opposite … and more: they reported being even more convinced there were WMD after the correction, arguing that this only proved that Saddam Hussein hid or destroyed them. In fact, Nyhan and Reifler note, among many conservatives “the belief that Iraq possessed WMD immediately before the U.S. invasion persisted long after the Bush administration itself concluded otherwise.”

If corrective facts only make matters worse, what can we do to convince people of the error of their beliefs? From my experience, 1. keep emotions out of the exchange, 2. discuss, don’t attack (no ad hominem and no ad Hitlerum), 3. listen carefully and try to articulate the other position accurately, 4. show respect, 5. acknowledge that you understand why someone might hold that opinion, and 6. try to show how changing facts does not necessarily mean changing worldviews. These strategies may not always work to change people’s minds, but now that the nation has just been put through a political fact-check wringer, they may help reduce unnecessary divisiveness.

Royals launch campaign to get Britons talking about mental health

William, Kate and Harry recruit celebrities and other individuals for videos discussing depression, anxiety and suicidal thoughts

The Duke and Duchess of Cambridge and Prince Harry help organise the Heads Together charity from Kensington Palace. 

Prince Harry and the Duke and Duchess of Cambridge have enlisted a rapper, a Royal Marine and a Labour spin doctor to try to push stigma about discussing mental health beyond what they believe is a “tipping point” and into public acceptability.

The royals are trying to use their high profile to convince the public that “shattering stigma on mental health starts with simple conversations”. The rapper Stephen Manderson, known as Professor Green, and the comedian Ruby Wax have joined other public figures and individuals who have suffered mental illness to make short films for their mental health campaign, Heads Together, and talk openly about their experiences of depression, anxiety and suicidal thoughts.

“Attitudes to mental health are at a tipping point,” the royals said in a joint statement. “We hope these films show people how simple conversations can change the direction of an entire life.”

In the clips Alastair Campbell, Tony Blair’s former director of communications in Downing Street, discusses his depression and breakdowns with his wife, Fiona Millar, including recalling how he got so low he punched himself in the face repeatedly. In another encounter the former England cricket captain Andrew Flintoff told Manderson: “The hardest thing for me initially was talking. I’m not a big talker. I’m from the north of England. I’m from a working-class family. We don’t talk about our feelings.”

“It was no different for me growing up in a council estate in east London,” replied the rapper. “It is just not something you spoke about.”

The royals also released the largest ever survey of public attitudes to mental health, conducted by YouGov, which found almost half the population had a conversation about mental health in the last three months. Women are more likely to talk about the issue than men and young adults are almost twice as likely to discuss it than people aged over 65.

However, very few of the 5,000 surveyed – just 3% – said they had approached someone from a local support organisation, and a similar amount, 2%, spoke to someone in the human resources department at work about the issue, despite almost 12m working days being lost to work-related stress, anxiety and depression in 2015-16.

Heads Together is a coalition of eight mental health charities, including Mind and the Campaign Against Living Miserably (Calm), organised from Kensington Palace. Prince Harry is championing the issue after fellow servicemen suffered post-traumatic stress disorder and following his time volunteering in the army’s personnel recovery units. Prince William is understood to have been motivated after attending several suicides as an air ambulance pilot, and the Duchess of Cambridge is said to be interested in how mental health affects family life.

By campaigning for people to help each other by talking more, the royals hope to avoid a more politicised issue: claims that funding for NHS mental health services is being effectively cut. Last November an analysis by the King’s Fund thinktank showed 40% of mental health trusts saw their income fall in 2015-16. This was despite the government’s commitment to parity of esteem for mental health and assurances from NHS England that almost 90 per cent of plans submitted by clinical commissioning groups (CCGs) last year included mental health funding increases.

Heads Together will be the London Marathon’s lead charity this year, and the former England footballer Rio Ferdinand and the comedian Stephen Fry have also recorded testimonies set to be released next month.

People from other professions have also contributed. Phil Eaglesham, a Royal Marine who completed tours of Afghanistan and Iraq, is filmed talking with his wife, Julie, about how his struggle with a debilitating illness resulted in him trying to take his own life, although he told no one.

“I was ashamed,” he said. “There’s a stigma around mental health and how that was perceived and at that point I felt I was weak.”

When he finally did speak out, “things improved and I got help”.

“There is no way out without talking,” he said.

The TV journalist and newscaster Mark Austin discusses with his daughter Maddy how he handled her anorexia.

“I couldn’t even come to terms with how to stop it or how to help you,” he told her. “It was like you were determined to kill yourself. I remember at one stage saying if you want to go ahead and starve yourself to death, you go ahead. I obviously didn’t mean it but I was so helpless.”

In the UK, the Samaritans can be contacted on 116 123. In the US, the National Suicide Prevention Hotline is 1-800-273-8255. In Australia, the crisis support service Lifeline is on 13 11 14. Hotlines in other countries can be found here


Kansas man donates 32 gallons of blood over 64 years

In a March 23, 2017 photo, Harold Facklam displays the many pins he has collected for having donated 32 gallons of blood over more than six decades, in Topeka, Kans. Facklam Jr. of Topeka recently was recognized by the Kansas Health Care Association and the Kansas Center for Assisted Living for the 259 pints he has donated through the American Red Cross. (Thad Allton/The Topeka Capital-Journal via AP)

 In a March 23, 2017 photo, Harold Facklam displays the many pins he has collected for having donated 32 gallons of blood over more than six decades, in Topeka, Kans. Facklam Jr. of Topeka recently was recognized by…TOPEKA, Kan. — An 87-year-old Kansas man who has donated 32 gallons of blood over more than six decades credits his father for his award-winning generosity.

Harold Facklam Jr. of Topeka recently was recognized by the Kansas Health Care Association and the Kansas Center for Assisted Living for the 259 pints he has donated through the American Red Cross, the Topeka Capital-Journal ( ) reported.

Facklam, who donated until health reasons caused him to stop in April 2015, said he doesn’t think about how his donations have affected others or even saved lives.

But he gave a nod to his late father, Harold Facklam Sr., who he said encouraged him to donate when the younger Facklam was almost 21 in 1951. Facklam’s father gave blood for about 11 years, stopping at age 60.

“My father was giving; he certainly had a great influence on me. He was very, so pleased to give and that’s why I started, of course,” Facklam Jr. said.

For years, the younger Facklam sprung to action every time a newspaper or radio announcement said the Red Cross would be in his area accepting blood donations. After each visit to the donor center, Facklam made his next appointment to do it again.

He donated a pint of whole blood four times a year, ultimately winning Kansas American Red Cross recognition with 38 pins as he reached specific gallon markers.

The generosity is running in the family; one of Facklam’s two daughters, a granddaughter and son-in-law have donated blood over the years.

Facklam also has been honored for his volunteer work with the United Church of Christ in Kansas’ Geary County, where he spearheaded the committee that rebuilt the church after lightning destroyed it in 2001.

“Church was a very important part of our life, always,” said Facklam, who has been married for 66 years.


I Said Hello To 10 People a Day For 10 Days. Here’s What Happened

Say Hello To 10 People In 10 DaysSay Hello To 10 People In 10 DaysI’m not an unsocial guy. I like to play poker and I’m in a slow-pitch softball league. But I’m also a writer who works at home, so I live a lot in my head, where I have conversations, debates, and arguments, all to enjoy some indignation. I’m suspect of overly positive people, but probably more jealous. I like to think that I’m engaged in the world, but I’ve built a callous to isolationism. It was time for a shakeup, and the one I chose was to say hello to 10 people a day for 10 days.

I consulted with Sharon Salzberg, co-founder of the Insight Meditation Society, author of Real Happiness and an expert on being present, and she laid out the ground rules. Everyone was fair game. The greeting had to be in-person, and my good intentions guaranteed nothing.

So I did it and I’ll start with my big reveal:

I felt happier, far from a groundbreaking result. Saying hello to feel more connected is the equivalent of breathing deeply to decrease stress. It’s simple, boring, and constantly recommended, and it happens to work. It also doesn’t cost anything, and it could save your life.

The bulk of my outside time, and this experiment, happened at my older son’s preschool. It’s a Jewish Community Center, so after I drop him off, I walk down the hall for a quick workout. The routine can zone me out. Having to say hello forced me to look up, and it was just like with sports. I’m better and have more fun when I pay attention and dictate play. I decided who I said hello to— it didn’t have to be everybody. And then it was a one-word commitment that didn’t have to break my stride, but…

Say Yes To Everything: <p>When you’re on the lookout for new friends, try to show up to everything you’re invited to. Yep, that includes your neighbor’s baby’s first birthday party and your friend’s cousin’s improv show. It might not be ideal, but you never know who you’ll end up chatting--and clicking--with.</p>7 Ways to Make Friends as an AdultIt gave enough of an opening. I ended up talking with people I knew, kind of knew and didn’t know. I learned about hockey tryouts and a fellow parent who has every tool to borrow. I also heard about job stresses and kid worries, stuff that made me realize I don’t have a monopoly on anything and made the people, and the place, feel more personal, because I was taking in actual information.

It wasn’t even necessary to have an actual conversation for me to make headway. There’s an old guy who works out at the same time as I do. He looks crusty, and that was enough to write his entire script. But I had a quota and was on my last set. I gave him a hello. He gave me a quick smile. Guy’s not so crusty anymore.

Saying hi to people never became automatic for me. Even on the last day, I’d forget and jump right into my business. The exchanges still worked, but felt rushed. Slipping up comes with a new habit, Salzberg says. The easy thing is to say “Screw it,” but it’s about being able to restart. And being less hardass on yourself. Again, it’s like sports. You can make mistakes and still win, but not if you implode.

There was a basic thing that happened almost immediately. The intention to say hello gave me a positive attitude. Conversely, I didn’t have time to be a jerk. It was impossible for those two things to co-exist. I don’t want to say I was making a choice, but I guess I just did.

In School Nurse’s Room: Tylenol, Bandages and an Antidote to Heroin

A naloxone kit at Washingtonville High School in Orange County, N.Y. 

At every school in New Rochelle, just north of the Bronx, in Westchester, there is a locked medicine cabinet in the nurse’s office, stocked with things like EpiPens for allergic reactions, inhalers for asthma, Tylenol for aches and pains.

Now, those cabinets also include naloxone, an antidote for people who are overdosing on opioids like heroin. Given as an injection or a nasal spray, naloxone can quickly revive someone who is not breathing. The city keeps it in every nurse’s office, including in its elementary schools.

“We have it the same way we have defibrillators and EpiPens, the way we have oxygen in our schools,” said Dr. Adrienne Weiss-Harrison, the school district’s medical director. “Rarely do we pull a defibrillator off the wall, but it’s there if we need it, and that’s how we approach this opportunity to have naloxone.”

There is no comprehensive data on how often students overdose while at school, but it happens. Renee Rider, assistant commissioner at the New York State Education Department, said the department has heard anecdotally of two schools where a student overdosed and was saved by E.M.S. workers using naloxone

But the numbers of young people dying from overdoses around the country is striking. According to the Centers for Disease Control and Prevention, in 2015, opioids killed 7,163 people between the ages of 15 and 29, more than 20 percent of total deaths.

And as communities across the country face this swell of death from heroin and pills, schools see the epidemic lapping at their doorsteps — killing friends, neighbors, recent graduates. Educators are increasingly deciding that they should have naloxone on hand.

New Jersey Assemblyman Vincent Mazzeo, a Democrat, in the fall sponsored a bill in the state legislature that would require all high schools to stock naloxone. In talking to parents and students in his district, Mr. Mazzeo said, “It came out that kids were coming into school on opiates, perhaps on heroin.”

Without the antidote, “If a kid comes into school and he overdoses, they don’t have the proper tools. They’d have to wait for E.M.S. first responders to come.”

Now, in Massachusetts and Kentucky, Connecticut and New Mexico, schools have the drug for emergency use. New York State has a program that provides it free to schools, with 64 districts participating so far. In Pennsylvania, nearly 250 public and charter schools have received a free supply. In Rhode Island, every middle school, junior high and high school is required to have naloxone on the premises. And scattered around the country, there are schools and districts that have bought the medication on their own.

“It is absolutely a sad sign of the times,” said Roy Reese, superintendent of Washingtonville Central School District in Orange County, N.Y. “I say this not reluctantly, but sadly: it is only a matter of time.”

Naloxone has been available for more than 40 years, and for much of that time, it was largely found in hospitals. But it has become increasingly common outside of them as the opioid epidemic has spread, and is now often found at the fingertips of law enforcement officers. In recent years, laws have changed to allow schools to keep it on hand and administer it to whoever needs it. In New York, for example, public health law was amended in 2015 to authorize school employees to administer naloxone.

Brian Connolly, principal of Washingtonville High School. The school keeps naloxone in the nurse’s office and with Mr. Connolly’s secretary. 

Through the state’s program, New York schools can now receive two doses of generic intranasal naloxone in a little nylon bag; the kits cost about $66, the State Health Department said, though schools get them for free. The drug is also available under the brand name Narcan, which is a nasal spray, and Evzio, which is an auto-injector like an EpiPen. Evzio is the most expensive, with a list price of $4,100, according to Kaléo, the company that makes it.

New York City schools are not stocking it because, officials said, they “have not seen the need.”

Many schools have chosen to stock Narcan because they can get it for free. A partnership between Narcan’s producer, Adapt Pharma, and the Clinton Foundation, offers any high school in the country two free doses of Narcan. Adapt Pharma covers the cost of the medication, and the Clinton Foundation does outreach to schools and districts. In an indication of the reach of the epidemic, President Clinton said last year that three of his friends had lost children to opioid overdoses.

An Adapt Pharma spokesman said about 1,300 units have been distributed so far to schools in 15 states, including Pennsylvania, Massachusetts, Kentucky, Delaware and New Hampshire. After the free supply runs out, schools can buy more for $75 a carton, which contains two doses. The list price for that amount is $125, Adapt said.

“I don’t see this as a big land-grab for market share,” said Daniel Raymond the deputy director of policy and planning at the Harm Reduction Coalition, which provides trainings on health issues related to drug use. “Ultimately, schools are going to be a niche market compared to other purchasers of naloxone.”

Kathleen Neelon, the nursing coordinator for the Wallingford, Conn., schools, said that in recent years, there has been an alarming numbers of overdoses among young adults in the area, so the district decided to stock Narcan for its high schools. They keep it in an emergency kit, which is filled with things like quick-clotting gauze and a blood pressure cuff.

“We instituted it in December, and I hope we never have to use it” Ms. Neelon said. The school sent out a notice to parents about the decision, and there were stories on the local news, she said, but she knew of no pushback from the community. “Most people said, it’s a sad statement, but it’s better to be prepared than not.”

Some observers wonder if the reaction would be different if schools were stocking an antidote to a different drug, like crack cocaine. The crack epidemic was particularly acute among black people, while the opioid epidemic has hit white people especially hard. Much has been written about how race has impacted the nation’s reaction to the opioid epidemic.

“If there was an antidote to crack, the argument would be we should just kick these people out of school, rather than trying to deal with them in the school system,” said Mr. Raymond of the Harm Reduction Coalition. “It would be about getting tough, cracking down, kicking them off of sports teams and expelling them.”

In many school districts, educators say the severity of opioid problem has overwhelmed any concerns they might have about the optics of naloxone.

Mark Marrone, superintendent of Mainland Regional High School in southern New Jersey, said he knows of several Mainland graduates who overdosed and died in their 20s, and one who overdosed and survived after being given naloxone. If the worst happens at his school, he said, he plans to be prepared.

“Some people worry that this says, ‘Oh, there are drugs in the schools,’” Mr. Marrone said. “No, there are drugs everywhere. We want to teach kids the right way to respond.” And maybe, he continued, “you’ll save a life.”

Quest for new antibiotics gets first major funding from global partnership

A major global partnership aimed at fighting superbugs announced Thursday that it is investing up to $48 million in research projects, including potentially the first new classes of antibiotics in decades, to target the deadliest drug-resistant bacteria.

The investments announced by CARB-X include $24 million in immediate funding for 11 companies. The firms can receive up to $24 million in additional payments over three years if they meet specific milestones.

The projects represent a broad range of approaches. Three companies are working on new classes of antibiotics, a significant development because the last class that made it to market was in 1984. Four companies are developing nontraditional therapeutics to boost the human immune response and disable pathogens’ ability to grow. Yet another company is pursuing a diagnostic imaging tool to identify the type of bacteria causing a lung infection within 60 seconds.

All the projects are in early stages of research, when risk of failure is high, officials said. CARB-X, which stands for Combating Antibiotic Resistant Bacteria Biopharmaceutical Accelerator, was launched in July to stimulate such critical early-stage work. Its goal is to jump-start drug development with money and access to expertise, supporting companies with promising antibiotic candidates so they can attract enough private or public investment to advance development and eventually win regulatory approval.

Funding comes from the Biomedical Advanced Research and Development Authority, or BARDA, part of the Department of Health and Human Services, and the Wellcome Trust, a London-based global biomedical research charity. CARB-X aims to invest $450 million over five years with the goal of speeding up preclinical discovery and development of at least 20 antibacterial products and moving at least two of them into human trials. The partnership, which also includes academic, industry and other nongovernmental organizations, was created as part of the U.S. and British governments’ calls for global efforts to tackle antibiotic resistance.

The projects announced Thursday were selected out of 168 applications that flooded in within the first four days that proposals were accepted.  “These projects hold exciting potential in the fight against the deadliest antibiotic-resistant bacteria,” said Kevin Outterson, executive director of CARB-X and a law professor at Boston University, where the partnership is headquartered.

Everything about developing new antibiotics is difficult, he said. On the science side, that means finding a drug that only kills the bad bacteria, leaving good bacteria and the rest of human cells untouched. The economics for antibiotics also turn market incentives “upside down” because, unlike most new products that companies rush to sell, the best antibiotics need to kept on the shelf — to be used for  “last-ditch cases,” he said.

And because resistance will always develop, antibiotics are “the only drug class where we have to start all over every time we succeed,” Outterson said.

But interest has been strong. Additional funds are likely to be awarded later this year, and another 200 applications have already been received for the next cycle.

All the potential medicines under development in this first phase target Gram-negative bacteria, among the most dangerous types of superbugs because they are increasingly resistant to most available antibiotics. They include CRE, or carbapenem-resistant Enterobacteriaceae, which U.S. health officials have dubbed “nightmare bacteria.”

These pathogens, which cause pneumonia, bloodstream infections, and wound or surgical site infections, have been identified by the Centers for Disease Control and Prevention and the World Health Organization as the greatest threat to human health. They have built-in defenses that include a double membrane barrier and a mechanism that expels drugs, such as antibiotics, from the cell.

Drug-resistant infections kill an estimated 700,000 people a year globally. The more antibiotics are used, the less effective they become as bacteria develop resistance to them. Scientists, doctors and other public health officials have increasingly warned that if antibiotic resistance continued at its current rate, routine infections eventually would be life-threatening ones. Common modern surgeries, such as knee replacements, could again become precarious.

Last month, the World Health Organization announced its first list of drug-resistant “priority pathogens” to guide and promote research and development of new drugs. Of the 40 antibiotics in clinical development in the United States, fewer than half have the potential to treat the pathogens identified by the WHO, said Allan Coukell, senior director of health programs at the Pew Charitable Trust’s antibiotic-resistance project.

Experts said they are excited by the research CARB-X is funding.

“It’s hitting the right targets for potential drug development,” said Kathy Talkington, director of Pew’s antibiotic-resistance project. “It’s covering a diverse portfolio of products. It addresses the need for novelty.”

Eight companies are based in the United States and three in the United Kingdom. The projects also will receive business and drug development support from the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, and other partners.

Companies that are developing potentially new classes of antibiotics include San Diego-based Forge Therapeutics, which was awarded $4 million over 15 months to spur development of a small molecule product to target an enzyme found only in Gram-negative bacteria and essential for its growth.

Visterra Inc. of Cambridge, Mass., was awarded $3 million over 12 months to develop an antibody with a potent antimicrobial compound engineered to kill all strains of the deadly Pseudomonas bacteria, including multidrug-resistant strains, the company said.

And Proteus IRC, based in Edinburgh, Scotland, is receiving $640,000 over 21 months to develop its technology to rapidly visualize bacteria in the deepest part of the human lungs.


Breastfeeding, Cognitive and Noncognitive Development in Early Childhood: A Population Study


BACKGROUND AND OBJECTIVES: There is mixed evidence from correlational studies that breastfeeding impacts children’s development. Propensity score matching with large samples can be an effective tool to remove potential bias from observed confounders in correlational studies. The aim of this study was to investigate the impact of breastfeeding on children’s cognitive and noncognitive development at 3 and 5 years of age.

METHODS: Participants included ∼8000 families from the Growing Up in Ireland longitudinal infant cohort, who were identified from the Child Benefit Register and randomly selected to participate. Parent and teacher reports and standardized assessments were used to collect information on children’s problem behaviors, expressive vocabulary, and cognitive abilities at age 3 and 5 years. Breastfeeding information was collected via maternal report. Propensity score matching was used to compare the average treatment effects on those who were breastfed.

RESULTS: Before matching, breastfeeding was associated with better development on almost every outcome. After matching and adjustment for multiple testing, only 1 of the 13 outcomes remained statistically significant: children’s hyperactivity (difference score, –0.84; 95% confidence interval, –1.33 to –0.35) at age 3 years for children who were breastfed for at least 6 months. No statistically significant differences were observed postmatching on any outcome at age 5 years.

CONCLUSIONS: Although 1 positive benefit of breastfeeding was found by using propensity score matching, the effect size was modest in practical terms. No support was found for statistically significant gains at age 5 years, suggesting that the earlier observed benefit from breastfeeding may not be maintained once children enter school.


  • Abbreviations:
    propensity score matching
    strengths and difficulties questionnaire
    structural equation modeling


What’s Known on This Subject:

The medical benefits of breastfeeding for mother and child are considered numerous, yet the effect of breastfeeding on cognitive abilities remains largely debated given selection into breastfeeding. The effect on behavior is even less well understood.

What This Study Adds:

In applying quasi-experimental techniques which mimic random assignment, this study supports limited positive impacts of breastfeeding for children’s cognitive and noncognitive development. Although significant, the effect of breastfeeding on noncognitive development is small in practical terms.

The medical benefits of breastfeeding for both mother and child are considered numerous and well documented.15 Yet the effect of breastfeeding on general cognitive abilities has been a topic of debate for nearly a century.6 The mechanism argued to be responsible for these effects is the nutrients found in breast milk.7,8 Two specific types of long-chain polyunsaturated fatty acids, namely docosahexaenoic (DHA) and arachidonic acid, have been implicated in both visual and neural development and functioning through neural maturation, which is important for cognitive abilities, such as problem solving.911

The link with nutrients may also impact specific cognitive abilities like language development. For example, language abilities, such as vocabulary, are highly dependent on working and long-term memory given the consolidation and retrieval processes needed during acquisition.12,13 In rats, deficiency of fatty acids, such as DHA, during lactation resulted in poor memory retention during learning tasks, whereas supplementation of DHA had reversal effects.14 If the hypothesized “causal” mechanism of superior nutrition in breast milk is true, coupled with the specific impact of DHA on memory, breastfeeding should also impact language abilities. To date, ∼20 studies have investigated this association and all but 115 examined a combined measure of language (receptive and expressive) or receptive language only. There remains debate as to whether expressive and receptive language in early childhood form distinct modalities of language,16,17 raising the question of whether breastfeeding would be equally beneficial to each modality in the case of a 2-factor language model.

Less studied is the impact of breastfeeding on behavior. Breastfeeding may lead to reduced behavioral problems as a result of early skin-to-skin contact, which helps form a secure mother-infant bond.18 Any effects of breastfeeding on cognitive and language development could also prevent the development of behavior problems. The absence of early behavior problems has social, economic, and medical value to society through reduced prevalence of delinquency, incarceration rates, and substance abuse,1921 making this an important area of research. With few exceptions, there remains a dearth of high-quality studies examining behavior,2225 and among them, consensus is not evident.

Without randomization of mothers to breastfeeding and formula conditions, it is challenging to confirm the causal impact of these hypotheses. One study randomized the provision of a breastfeeding intervention, modeled on the Baby-Friendly Hospital Initiative, and found that the children of mothers in the intervention group had higher intelligence scores compared with controls at age 6 years.26 The strongest effects were for verbal intelligence. This study offers the best support to date for a causal link between breastfeeding and cognitive development. However, it is the only cluster randomized trial on human lactation.

The majority of studies in this field are observational, thus the causal implications of breastfeeding are questionable given the inherent difficulty in controlling for selection into breastfeeding. For example, initial associations with cognitive development are often reduced after adjustments for confounders, such as parental education/IQ (ie, from an average 5-point to 3-point difference27), and, in some cases, the associations are no longer statistically significant.28 A variety of observational studies now apply quasi-experimental methods to better address the issue of selection bias, making inroads toward a better understanding of potential causal paths. The techniques used include propensity score matching (PSM), instrument variables, and sibling pair models. This study uses PSM because the sibling pair model limits the available pool of participants and instrument variables are extremely sensitive to the validity of the chosen instrumentation, which should be associated with the exposure but not with the outcome except for via the exposure.

Using a large longitudinal population sample, we applied PSM, which mimics random assignment, in an effort to investigate the potential impacts of breastfeeding on children’s cognitive ability, expressive vocabulary, and behavior problems. Both breastfeeding duration and intensity were examined. Significant advantages for children who were breastfed, after matching, were expected for all outcomes. Grounded in the recommendations of the World Health Organization,29 it was expected that larger effect sizes would be observed for children who were fully breastfed and for longer durations.



Participants included families enrolled in the Growing Up in Ireland infant cohort. Families with infants born between December 2007 and May 2008 were identified from the Child Benefit Register and randomly selected to participate. The overall recruitment response rate was 65% (N = 11 134). A detailed description of the study design can be found elsewhere.30 We used data collected at 9 months and 3 and 5 years of age. Only families with complete data for all confounders when children were 9 months and children who were born full term were included (N = 9854; 88.5% of the initial sample). Boys represented 50.6% (N = 4991) of the sample. Attrition across waves reduced the sample size to 8715 children at 3 years and 8032 at 5 years. Some children had missing data on the cognitive and vocabulary scales, resulting in 8535 and 8241 children respectively at age 3 and 7972 and 7942 children respectively at age 5. Additionally, missing teacher reports for behavior at age 5 years resulted in 7478 children being included in these analyses. Demographic characteristics of the families and rates of breastfeeding engagement can be found in Table 1 and Fig 1. Ethics approval was obtained from the Research Ethics Committee, Department of Children and Youth Affairs Ireland, and written consent was collected from parents/guardians before data collection.


Family, Maternal, Infant, and Medical Characteristics: Infant Cohort at 9 Months


The category “1” on the x-axis represents breastfeeding up to 31 days; “2” represents between 32 and 180 days; and “3” represents ≥181 days.


Children’s cognitive abilities and expressive vocabulary were measured by using 2 scales from the British Abilities Scale31. The pictures similarities scale assessed problem-solving skills and the naming vocabulary scale assessed expressive vocabulary. The construct validity of each scale was derived by using the Wechsler Preschool and Primary Scale of Intelligence-Revised (r = 0.74 and 0.83, respectively).31 Standardized scores that adjusted for performance as compared with other children of the same age, with a mean of 50 and a SD of 10, were used. Age was adjusted in 3-month age bands.

The Strengths and Difficulties Questionnaire (SDQ32) was used to assess children’s problem behaviors. The parent version was used at age 3 years and both the parent and teacher versions were used at age 5 years. The SDQ is comprised of 5 scales (emotional symptoms, conduct problems, hyperactivity/inattention, peer relationship problems, and prosocial behavior) with ratings of applicability of behaviors on a 3-point scale. A total difficulties scale is included, combining the 4 problem scales, to yield an overall difficulties score. We used the conduct problems, hyperactivity/inattention, and difficulties scales given our focus on externalizing problems. Validation of the SDQ has been extensively documented.33Table 2 reports the correlations between parent and teacher SDQ reports and the means and SDs for all child outcomes.

Breastfeeding information was collected retrospectively when infants were 9 months old via maternal report. Support for the reliability of recall in previous breastfeeding studies has been established.34 However, given the lower reliability regarding the timing of the introduction of additional fluids/solids, Labbok and Krasovec’s definition of full (ie, exclusive or almost exclusive) and partial breastfeeding are used.35 Two breastfeeding variables were created to assess whether the infant was fully or partially breastfed and the duration of each. Mothers were asked 4 questions: “Was <baby> ever breastfed,” “How old was <baby> when he/she completely stopped being breastfed,” “Was <baby> ever exclusively breastfed,” and “How old was <baby> when he/she completely stopped being exclusively breastfed?” First, infants were grouped by breastfeeding status, both full and partial (5940) and never breastfed (3914). Of those who had ever been breastfed, 4795 had full breastfeeding at some point. Next, breastfeeding duration was grouped into 3 intervals; breastfed up to 31 days, 32 to 180 days, and ≥181 days. Each category of duration was treated as mutually exclusive, dummy coded, and compared against infants who had never been breastfed for the purpose of matching.

Confounders have been suggested in part to account for the associations found between breastfeeding and child outcomes. We matched groups (breastfed, never breastfed) on 14 of the most pertinent factors. At the child level, factors included sex (boy/girl), birth weight (≥2500 g), and having neonatal intensive care (yes/no). At the maternal level, factors included age (≤24 years, 25–29 years, 30–34 years, or ≥35 years), highest level of education (primary level/no education, second level, or third level), working status before pregnancy (yes/no), ethnicity (Irish, any other white background, African or any other black background, Asian background, or other, including mixed background), depression (a score of ≥11 on the Center for Epidemiologic Studies Depression Scale), and type of delivery (vaginal or caesarean). Family-level factors included having a partner in the residence (yes/no), social class (professional/managerial, other nonmanual/skilled manual, or semiskilled/unskilled), medical card status (free medical care, free general practitioner care, or no free medical care), total number of household members who smoked during the pregnancy (none, or ≥1), and whether the cohort infant had siblings living in the household.

Statistical Analysis

PSM reduces selection bias by matching children who were breastfed to children who were not, but who had a similar probability of being breastfed based on their measured characteristics. We used PSM logit models with nearest neighbor 1:1 matching techniques. In nearest neighbor matching, the sample is randomly ordered with matching occurring sequentially between the treatment (breastfed) and control (not breastfed) group based on participants’ propensity scores. Typically, the pair is then removed from the list and the next match is created. To ensure optimal matches, we imposed a caliper so that pairs could only be matched if the propensity score was within a tenth of a SD of the other. We also allowed matching with replacement given the low rates of longer durations and full breastfeeding in this cohort. Although matching with replacement has been argued to increase variance in the data, it also arguably reduces bias in the sample by ensuring better quality of matches.36 Balance checks in all models revealed substantial reductions of bias between matched groups on all individual confounders (ie, 0%–13.9% remaining bias in partial breastfeeding models, 0%–18.1% remaining bias in full models; data available on request). The remaining overall mean bias across models ranged from 3.2% to 8.5%. The ≤20% remaining bias has been suggested as the acceptable cutoff after matching.37 Thus, we concluded that the analytic matching technique resulted in good matches between conditions. Matching resulted in all participants falling within the area of common support. The average treatment effect on those who were treated (ie, children who were breastfed) is reported. Adjustments were made for multiple hypothesis testing by using the Holmes-Bonferroni method. All statistical analyses for PSM were conducted by using Stata version 13 software (Stata Corp, College Station, TX).

To note, although PSM is advantageous in mimicking random assignment, a drawback is the challenge in evaluating a linear dose-response association, which has previously been found. Structural equation modeling (SEM) offers an alternative approach to examining this dose-response association. Additionally, SEM uses the full sample and has greater power. Thus, the data were also modeled by using SEM, where confounders were treated as correlated exogenous variables, the duration of breastfeeding was treated as a continuous mediating variable, and child outcomes were treated as correlated, which could be influenced by both breastfeeding and confounders. These results can be found in the Supplemental Material.


Postmatching results for children fully breastfed up to 31 days revealed no statistically significant differences between groups on any outcome at age 3 or 5 years (Table 3). Similarly, for children who were fully breastfed between 32 and 180 days, no statistically significant differences were found for any outcomes at either age postmatching (Table 4). Finally, for children who were fully breastfed for ≥6, statistically significant differences were found postmatching for only 2 outcomes, problem solving and hyperactivity at age 3 years. Children who were fully breastfed scored 2.95 (SE = 1.39, P = .048) points higher on the problem-solving scale compared with children who were never breastfed and –0.84 (SE = 0.25, P ≤ .001) points lower on the hyperactivity scale. After adjustment for multiple testing, cognition was no longer statistically significant. However, children who were fully breastfed had slightly lower parent-rated hyperactivity compared with controls, and this remained statistically significant after adjustment (Table 5). Of note, results of the partial breastfeeding models were similar to the full models, however, after adjustment for multiple testing, neither cognitive ability nor hyperactivity at age 3 years remained statistically significant. These results can be found in the Supplemental Material.


Without randomized controlled trials, the issue of causality will necessarily remain open, however the present results contribute important insights to the long-standing debate of potential “causal effects” versus artifacts of confounding that are not properly accounted for. This study also provides new perspectives on breastfeeding and children’s externalizing behavior. To the best of our knowledge, this is among the first studies to examine expressive vocabulary as an individual outcome and to consider externalizing behavior. It should be noted that our results apply only to infants born full term.

After adjustment for multiple testing, the initial support found for breastfeeding and better problem solving at age 3 years if the child was breastfed for a minimum of 6 months was no longer statistically significant. In addition, no statistically significant effects were found for cognitive ability at age 5 years. These results are in contrast to some studies that have used PSM techniques to examine the effects of breastfeeding and general cognitive abilities.3840However, differences in both analytical choices of the PSM approach used (eg, replacement, calipers) and differing selection of covariates may help to explain these differences across studies. Nonetheless, our findings were surprising in the context of the nutrients in breast milk being responsible for increased cognitive development. Regarding expressive vocabulary, no statistically significant advantages were observed for children who were breastfed at either age 3 or age 5.

The limited research on breastfeeding and behavior problems is inconsistent, despite the relatively consistent reliance on the SDQ. Of interest, studies that have dichotomized the SDQ scales into abnormal scores (ie, at the 85th or 90th percentile) have not found statistically significant differences,2325 suggesting that breastfeeding is not likely to be a contributor to behavioral problems at clinical levels. When the SDQ scales are treated as continuous, small effects under certain conditions have been found.22 In this study, we treated all 3 scales as continuous and found that children who were fully breastfed for ≥6 months had lower parent-rated scores on the hyperactivity scale at age 3 years only. This result remained statistically significant after adjustment for multiple testing. Our results suggest that longer durations of breastfeeding might help to reduce hyperactive behaviors for children who display mild to moderate levels in the short term, but that these benefits are not maintained even in the medium term. This result would seemingly support the recommendation of the World Health Organization, suggesting that breastfeeding for at least 6 months is necessary for early gains to be observed.

The inherent strengths of this study include the use of a particularly large longitudinal developmental dataset, the use of a quasi-experimental statistical approach, the use of a repeated measures design, the use of multiple informants and simultaneous standardized assessments thereby limiting potential shared method variance, the comparatively large number of confounders controlled (ie, 14) in contrast to previous studies (ie, an average of 7.7 ± 3.4 in higher-quality studies28;), and assessments in both cognitive and noncognitive domains of child development. Despite these strengths, some limitations must be noted. First, information on breastfeeding was collected retrospectively. Although the reliability of recall has been established,34 it must be acknowledged that recall bias may nevertheless be present, particularly regarding the duration of full breastfeeding. Second, only parent-reported SDQs were collected when children were 3 years of age. Studies have found that parents typically rate their children as having higher levels of problem behaviors as compared with teacher reports, with weak associations between these 2 types of informants,24 as was found in the current study for behavior ratings at age 5 years between parents and teachers. Having access to child care staff reports at age 3 years would have increased the reliability of the maternal-rated hyperactivity finding. Third, no information pertaining to direct breastfeeding versus expressed breast milk feeding was collected. Thus, it is not possible to investigate whether the association with reduced hyperactivity at age 3 years was the result of skin-to-skin contact or due to the nutrients in breast milk. This is an important direction for future studies examining behavioral outcomes. Fourth, although maternal education was included as a confounder, maternal IQ was not collected in this cohort. In the few studies that controlled for maternal IQ, the findings suggested that it accounted for a large part of the association between breastfeeding and cognitive outcomes.39,41 Thus, the inclusion of maternal IQ in future studies that employ PSM is warranted. Finally, PSM does not address selection on unobservables. Causal estimates may only be estimated by using PSM if selection is on observable characteristics or, in cases where unobservable factors influence selection into breastfeeding, the balancing on observables also balances on these unobservables. Despite these limitations, the results of this study add to the growing literature by showing that some statistically significant positive noncognitive benefits may result from longer durations of breastfeeding. Yet, beyond the statistical implications, the practical implications appear minimal and short lived. It is important to note, however, that these findings do not contradict the many medical benefits afforded to both mother and child as a result of breastfeeding.


  1. Source:The American Academy of Pediatrics

Breastfeeding Doesn’t Provide Cognitive Benefits After All, Study Finds

But doctors still recommend it.


While breastfeeding is often recommended by doctors to help protect newborns from infections and diseases, the question of whether breastfeeding actually leads to cognitive benefits for infants isn’t so well settled.

Despite previous studies indicating that breastfeeding has a positive impact on children’s intelligence – which researchers say could be due to nutrients in breast milk – a new study now suggests that there are no long-term cognitive benefits to breastfeeding.

 Using data from the Growing Up in Ireland longitudinal study, a team from University College Dublin studied 7,478 children, whose cognitive abilities were assessed at ages three and five.

During the assessments, children were tested on their problem-solving and vocabulary skills, and were also evaluated in terms of their behaviour, including assessing their emotional symptoms, hyperactivity, and relationships with others.

The researchers found that after accounting for socio-economic variables such as parents’ education and income, there was no strong evidence to suggest that children who had been breastfed as babies demonstrated cognitive benefits over babies who hadn’t.

“[W]e didn’t find any statistically significant differences between children who were breastfed and those who weren’t, in terms of their cognitive ability and language,” one of the researchers, Lisa-Christine Girard, told Katie Forster at The Independent.

But on one measure, the results did show a contrast.

“We did find direct effect of breastfeeding on a reduction in hyperactive behaviours when the children were three years old,” says Girard. “This wasn’t found at five years, suggesting there may be other factors that are more influential as children develop.”

 In other words, it’s possible that the notion that breastfeeding confers a benefit to children’s intelligence hasn’t successfully accounted for all the parental, lifestyle, and other socio-economic factors that can also influence a child’s development and upbringing.

“I think [the study] fits well in the body of literature that long-term benefits of breastfeeding look a whole lot smaller or non-existent if you properly control for your confounding variables,” statistician Brooke Orosz from Essex County College in New Jersey, who was not involved with the study, told CNN.

“The easy question – do kids who are breastfed have better outcomes? The answer is yes. The difficult question is: is it breast milk that improves their brain, or is it that growing up with parents who are better educated and have better incomes makes a difference?”

While the new study might not be able to provide a definitive answer on that issue, the results do seem to suggest that socioeconomic factors could have played a part in skewing previous data – but Girard’s team doesn’t expect this to be the end of the discussion.

“This has been a debate for over 100 years, and we’re working hard to understand the complete picture,” she told Allison Aubrey at NPR.

In any case, while researchers will continue to investigate the link – if any – between breastfeeding and developmental benefits, scientists say the new study shouldn’t dissuade anybody who wants to breastfeed from doing so, given the commonly accepted health and nutrition advantages.

Of course, not every mother is able to breastfeed, due to a range of conditionsthat make breastfeeding difficult or impossible for some – but for women who don’t experience those complications, the advice from physicians is firm.

“There’s a strong body of evidence to support that breastfeeding is one of the healthiest things we can do to support children’s immune systems,” paediatrician Ellie Erickson from Duke University, who wasn’t involved with the study, told NPR.

On that issue, at least, it’s a point that the study authors are in complete agreement with.

“The medical benefits of breastfeeding for both mother and child are considered numerous and well documented,” the researchers write in their paper.

“[T]hese findings do not contradict the many medical benefits afforded to both mother and child as a result of breastfeeding.”


Largest Ever Brain Cancer Study Provides Key Insight Into One of Its Deadliest Forms

This could change the way we think about brain tumours.

As far as cancers go, one of the worst is a type of brain cancer called glioma – the disease has a five-year survival rate of just 5 percent, and no reliable method for early detection.

A giant study that pooled genetic data from tens of thousands of people could change that, finding more than a dozen new mutations for physicians to hunt for in an effort to identify who is at risk of developing glioma.

 The results could end up boosting the chances of an early diagnosis, and saving lives in the process.

Together with researchers from the US and Europe, scientists from the Institute of Cancer Research in the UK carried out two studies on the human genome in an effort to spot differences that could result in cancer of the brain’s glial cells.

Our central nervous system relies on neurons to do its ‘thinking’ work, but they’re far from the only cell in the neighbourhood. For example, glial cells provide support for the neurons by insulating them, holding them in place, and helping them access nutrients.

But like a number of tissues in the body, changes in the genes inside these ‘nanny’ brain cells can cause them to grow out of control, prompting cancerous tumours to develop.

Glioma can be further broken down into categories, depending on the type of glial cell they started out as. Glioblastoma multiforme (GBM), for example, is a common form of brain cancer that begins as a type of glial cell called an astrocyte.

Tumours that grow into glioblastomas are particularly aggressive, killing around 95 percent of patients within five years.

 GBM develops in around 3 out of every 100,000 people, mostly striking in those over the age of 60, and claiming approximately 13,000 lives in the US and 5,000 lives in the UK each year.

While many researchers have been looking for new and innovative ways to treat gliomas, early detection has often been more accidental than intentional.

An Ohio State University study conducted in 2015 identified interactions between a pair of proteins and the newly developed tumour which could lead to a test that allows oncologists to diagnose a tumour as much as five years before symptoms appear.

But by identifying the genes that increase the risk of developing glioma later in life, researchers could potentially produce a program of diagnosis and quick treatment that might prevent tumours from growing in the first place.

This recent study didn’t stop at scanning the genome; it also analysed over 30,000 people included in a number of previous studies on GBM and non-GBM cancers, producing the largest ever study into brain cancer research.

All up, the research compared 12,496 cases of glioma with 18,190 people who didn’t have the cancer, finding 13 new locations on the genome which – if changed – could lead to glioma.

“The changes in the way we think about glioma could be quite fundamental,” says Richard Houlston from the Institute of Cancer Research.

“So, for example, what we thought of as two related sub-types of the disease turn out to have quite different genetic causes which may require different approaches to treatment.”

In total, researchers now have strong evidence for 26 locations on the genome that individually increase the risk of developing a form of glioma, in one case by up to 15 percent.

That might not seem like a lot, but when the odds are stacked against those with a metastatic brain tumour, every clue could make the difference between life and death.

“Understanding the genetics of glioma in such detail allows us to start thinking about ways of identifying people at high inherited risk, and will open up a search for new treatments that exploit our new knowledge of the biology of the disease,” said Houlston.

Combining past studies to increase the pool of data is a useful way to spot small differences which have otherwise been missed.

Hopefully this is one record we’ll see broken some time soon.


Not Kidding – a Comet Is Making Its Closest Pass to Earth Since Its Discovery This April Fool’s Day

Watch it live!

An iconic comet will be zooming past Earth this weekend, just in time for April Fool’s Day. Which, admittedly, does sound a little suspicious, but we promise this is definitely not a prank.

Comet 41P/Tuttle-Giacobini-Kresak was first detected back in 1858, and circles the sun every 5.5 years. This year, it will be making the closest flyby of Earth since its discovery, allowing us to catch an unprecedented glimpse as it zooms past at a very safe distance of around 21.2 million km (13.2 million miles) away.

 That’s a distance of 0.14AU, or a little over a tenth of the distance between Earth and the Sun.

Northern Hemisphere stargazers with small telescopes and potentially even binoculars will have the chance to see the comet from dark vantage points between dusk and dawn from now until mid-April, when it will be passing across the stars of the constellations Ursa Major and Draco.

But on April 1, the viewing will be particularly good, with the comet at its closet point to Earth since its discovery more than 150 years ago.

If you’re more of a hobby skywatcher, are located in the Southern Hemisphere, or are struggling with bad weather, don’t worry, you can watch it live here via Slooh’s coverage from its telescopes on the Canary Islands, starting at Friday 31 March, 8.30pm EDT (Saturday 1 April, 00:30am UTC).

So what can you expect to see? Well, unlike the green comet that streaked past earlier this year, Comet 41P isn’t particularly dazzling.

Comet 41P, as it’s known for short, belongs to a group of comets known as Jupiter comets, which have been captured by Jupiter’s massive gravity, and are now in orbit between the Sun and the gas giant.

 It’s also not particularly large – usually it appears in the night sky as a diffuse blob of light, no brighter than 8th magnitude, which means it’s only as visible as Neptune in the night sky, and is roughly 50 times too faint to be seen with the naked eye.

Good binoculars or small telescopes will be needed to pick it out, as well as a dark, clear, moonless night.

But, this year could provide an exceptional opportunity – scientists are predicting that the comet could undergo a dramatic outburst in brightness as it approaches the Sun.

This happened back in May 1973, just before the comet arrived at perihelion – its closest point to the Sun.

Unexpectedly, the comet’s brightness surged by 10 magnitudes, which meant it became 10,000 times brighter over just a few days, making it visible to the naked eye.

“Nobody knows for sure why the comet abruptly flared in 1973, but careful scrutiny of recent approaches to the sun in 1995, 2001, and 2006 suggest that outbursts in brightness tend to occur around the time [the comet] is passing closest to the Sun,” explains astronomer Joe Rao, from New York’s Hayden Planetarium, for

The good news is that this year, perihelion occurs on April 12, just a little over a week after it zooms past Earth, which means we could be in store for another brightening event.

How dramatic that will be, or if it’ll occur at all, is anyone’s guess.

Just in case, we’re going to be watching it from the comfort of our couches over at Slooh.

If nothing else, it’s a good excuse to escape all the craziness of the internet on April Fool’s Day with some much needed perspective about the vast scale of our Solar System, and all the fascinating objects that travel through it.

Happy skywatching!


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