Thursday, March 26, 2015

Understanding Anorexia

Stacey C. Cahn, PhD explores causes and treatment of anorexia nervosa, the most dangerous eating disorder.

Eating disorders are serious, debilitating conditions associated with significant morbidity and mortality, and distress. Anorexia nervosa, in particular, is associated with the highest mortality and suicide rates;  compared to healthy peers, women with anorexia are up to 12 times more likely to die of any cause, and approximately 57 times more likely to die from suicide, over the same period of time. 

The best predictor of positive treatment outcome in anorexia nervosa is early detection and intervention. Those suffering from eating disorders often feel shame, isolation, and face stigma. Children who experience anorexia may have difficulty understanding, much less explaining, their symptoms.  Others may not want to let go of perceived “benefits” of their eating behavior. So, for a variety of reasons, many suffer in silence and secrecy, which can serve to dangerously delay intervention. 

What causes some people to develop anorexia?
First, it's important to recognize that there is a genetic component to anorexia.  Someone with a first-degree relative who's had anorexia is at much greater risk for anorexia than someone without a family history.  So individuals have varying levels of biological "predisposition" to anorexia.  Other risk factors fall into two categories:  1) risk factors for psychiatric problems in general, including anorexia; and 2) risk factors specific to anorexia.  
General risk factors include low mood, a history of physical and sexual trauma, general family problems, and a parent with a psychiatric disorder.  These all appear to increase one’s risk for later mental health problems, including eating disorders.  
Specific risk factors for anorexia include: being female, age (early-mid adolescence is the prime time for onset), perfectionism, and concerns about shape and weight (and subsequent dieting).  Shape and weight concerns may be intensified by participation in competitive sports such as gymnastics, track, swimming or dance, where shape and weight are often related to performance.

Why is anorexia more prevalent in women? 
We don't really know for sure. Anorexia is relatively uncommon—historically, only about 0.3 percent of the population suffer from anorexia.  (Recently, however, the American Psychiatric Association has broadened the diagnostic criteria for anorexia nervosa slightly, so the official prevalence will likely rise somewhat.) Of those who suffer from anorexia, only about 10 percent are male; it's hard to get good data on a population that small. It does seem that cultural factors at least partially explain this gender discrepancy; thinness is more central to our culture’s “feminine beauty ideal;” there’s not an equivalent standard for men. Accordingly, men, overall, have less dissatisfaction with their bodies, and are therefore less likely than females to diet for weight loss, even if they are overweight. This disparity is significant because body dissatisfaction and dieting are risk factors for anorexia.

Are there any promising new treatments in development? 
Anorexia nervosa is notoriously difficult to research and treat. Treatment effectiveness has generally been disappointing due to a host of factors including the ambivalence about recovery intrinsic to the disorder.  

One psychological treatment that seems particularly promising is Enhanced Cognitive-Behavioral Therapy (CBT-E). Oxford University psychologist Christopher Fairburn and his colleagues have made impressive strides with their recent treatment research in Europe; they’ve conducted rigorous clinical trials testing CBT-E for adolescents and adults with anorexia. Compared to earlier treatment outcome studies, a remarkable number of those who completed the treatment had maintained their gains sixty weeks after treatment. Still, the most important predictor of positive outcome in anorexia is early identification and intervention. In general, the longer the duration of illness before treatment, the worse the prognosis.

Understanding that vaccines do not cause illness

Jessica Glass Kendorski, Ph.D., NCSP, BCBA-D

Vaccination—the word has become quite divisive. On both sides, we find well-meaning, intelligent, good parents who just want what is best for their children, and to protect them from harm. The science behind the benefits of vaccinating are clear (see this Healthy Kids blog about the importance of herd immunity), and the recent measles outbreak shows the consequences when individuals do not vaccinate. The total number of cases is up to at least 155 cases in 16 states. Over the weekend, New Jersey became the latest state to join the list.

So why are well-meaning, intelligent, parents, putting themselves and their children at risk? Part of the reason is because many people have not personally experienced the devastation of some of these viruses for which we now have vaccines, causing them to underestimate the seriousness of illnesses like measles. But there’s another factor in play: a natural, predictable bias in the way humans are wired to think, a bias known as the post hoc fallacy--the natural tendency for us to see causation in two events that co-occur in time.

The post hoc fallacy, fully named “post hoc ergo propter hoc” translates from the Latin “after this, therefore because of this.” It is an error in logic to assume that if event 1 occurs right before event 2, then event 1 necessarily caused event 2. As a personal example, my daughter received her booster MMR vaccination when she was 4 years old. The very next day she developed a rash and spiked a 104-degree temperature. I was scared, but, fortunately, it was clear to me that this probably wasn’t because of the vaccination; her 2-year old brother had had the same rash and high temperature a few days prior, and had been diagnosed with the Hand, Foot and Mouth virus. It would have been natural for me to blame the MMR vaccination for her illness (since one occurred right before the other), but I had the “benefit” of having another kid in the house with similar symptoms who 1) had been diagnosed with a highly contagious illness, and 2) had not been recently vaccinated.

Young kids get sick with regularity.  Young kids get vaccinated with regularity. Therefore, there is a reasonable chance that your child will get sick some time after receiving a vaccine, without the two events being related.  Similarly, with Autism Spectrum Disorder, symptoms begin to emerge around the same time that toddlers routinely receive the MMR vaccination. This timing predictably causes some parents to question whether the vaccination caused the disorder, when there is no evidence that suggests the two are related, and substantial evidence supporting that the two are unrelated.

This tendency to equate causality with timing has long been shown in the behavioral science literature. Take B.F. Skinner’s experiment with pigeons. The birds would receive a food pellet at random intervals from a machine. After a certain amount of time, they would perform whatever random activity they had done before receiving the pellet, as if that action would produce it. This is exactly why humans strive to understand what happened —what they did—to cause an event. And, it’s the reason why so many parents are convinced that a particular vaccination can cause an injury or disorder, when in reality, the two are unrelated.

If we want to increase the number of people who vaccinate their children, explaining the science is not enough. We must understand the natural tendency for people, all people, to equate coincidence with causality. We must recognize the stories that people tell about their child getting sick are very real, and very heartbreaking. We must help people understand the fallacy in their logic; that just because two things occur together does not mean that one caused the other. Any successful message has got to include real empathy.  Empathy for these very, well-intended parents, who have only the best interest of their beloved children at heart.  

Why we shouldn't physically punish our kids

Jessica Glass Kendorski, Ph.D.,NCSP, BCBA-D

The recent arrest of Minnesota Vikings Running Back Adrian Peterson has sparked a divided reaction within the NFL around the use of physical punishment with children.

Peterson’s lawyer, for example, said that Peterson “used the same kind of discipline…that he experienced as a child.” Former basketball player and current NBA analyst Charles Barkley also defended Peterson, while ESPN’s Chris Carter (a former Viking himself) noted, “You can't beat a kid to make them do what you want them to do." This range of reaction echoes the national debate surrounding physical punishment. But, existing research tells us that Carter is right.

Researchers define physical punishment as “the intentional infliction of pain and discomfort and/or the use of force to stop or change a behavior.” A 2008 study on the effectiveness of physical punishment on children in the U.S. found no long term effects on behavior change; essentially, when the threat of punishment was gone, the negative behavior returned.

Additionally, there is extensive research that physical punishment puts children at substantial risks for future defiant and aggressive behavior, increased mental health concerns, as well as greater risk of serious injury and abuse. Recent brain science research has shown that harsh physical punishment may actually have detrimental effects on the development of a child's brain.

The negative effect of punishment, physical or otherwise, extends to our schools as well. Many schools adopt “zero tolerance” policies, but in order for those to work, educators must discipline students in harsher ways, often with little effect. The US Department of Education reported in 2011 that there were more than 3 million suspensions per year and over 100,000 expulsions. What’s more, consistent use of punishment in schools causes children to become fearful and avoidant of school and teachers, and interferes with positive, pro-social relationships. Brain science is showing us that warmth and nurture are essential to brain development. Academic success—one of the best indicators of adult success—is best achieved in a school climate that is warm, welcoming, and promotes positive behavior and positive interactions with adults and peers.  In order to reduce the use of physical punishment, we must have other options.

Children learn to behave when their parents notice and respond to their behavior appropriately. When a child misbehaves, it is essential that parents remain calm (provide appropriate time outs if necessary) and communicate the appropriate way to get it right next time.  Techniques such as teaching behaviors that you want to see (keeping your hands to yourself and why); Reinforcing specific behaviors (keeping your hands to yourself); Modeling appropriate behavior (parents keep their hands to themselves); and reinforcing a low preferred behavior (doing homework) with a high preferred behavior (playing a game) are effective ways to encourage appropriate behavior.

The risks to physical punishment are huge and well outweigh the short term reduction of a negative behavior. It's time to change the culture of discipline in our country, and to show parents that there is a better way. Rather than debate its effectiveness (the research is clear on that), let’s educate on its tremendous risks, and on more positive approaches to discipline. It is not too late to change our educational and parental discipline practices. Our kids deserve better. 

Friday, October 3, 2014

Walk Out of the Darkness

Petra Kottsieper, Ph.D.

On October 5 the annual Walk Out of the Darkness, held by the American Foundation for Suicide Prevention will take place here in Philadelphia as well as many other cities around the country.
I will be walking in this walk as a person who came very close to losing a family member to suicide, know people who have successfully committed suicide, as someone who has a past history of mental health concerns,  and as a mental health professional.

"Suicide claimed 39,518 lives in 2011 in the United States alone, with someone dying by suicide every 13.3 minutes. A suicide attempt is made every minute of every day, resulting in nearly one million attempts made annually."

Losing someone to suicide is a profound event, sometimes not surprising to the families and friends of the person who choose to end his or her life, and sometimes it explodes into people’s lives completely unexpectedly. Many people who attempt or complete suicide experience extreme psychological pain and suffering and often see suicide as the only way out.  Often, people are unable to reach out in their darkest moments despite the relatively abundant resources that exist in the US. Why is this?

Stigma, fear, and hopelessness are all answers to this question. Stigma of mental illnesses remains a significant barrier to help seeking. Public stigma is not just grounded in the well documented beliefs and resulting stereotypes that people who are "crazy" are dangerous and unpredictable, but also in the fact that having "mental" problems is seen as something fundamentally different than having a "physical" problem. And while mental and physical illnesses may very well experientially vary, problems with mental health concerns are observed not only as different, but are also judged as worse. This is undoubtedly rooted in our perception of the superiority of the mind over our body; mind as the seat of our "rationality" and emotional balance.  In addition, some "mental health” problems, obviously due to their complexity, remain poorly understood.  In other cases we know a lot, have effective treatments, but these treatments are still not considered readily acceptable to be sought out.  Acknowledging that a family member, friend, or even oneself is having a mental health concern means that one has to accept this in the context of likely societal distancing and associated negative judgments.       

This is where the annual walk comes in.  The walk addresses what is at the heart of the pervasive problem of stigma that continues to exist and makes it hard for many people to seek help for the problems they are experiencing. The walk is about "coming out," shining a light on the significant public health issues of suicide and having survivors come together being visible and open about having lost a family member without fear and embarrassment. Ending the taboo.

So what can we do as friends, family members, professionals, individuals who are struggling?
As a society we need to become so much more aware of what mental health problems really are. In addition to understanding their etiologies we also need to understand suicidal ideation as a phenomenological experience. This is especially important for professionals who need to work on gaining a better understanding of suicidal thoughts of his or her presenting patient.  We need to talk to people about suicide, and research indicates that even as professionals we are often not comfortable with this topic.[i]  We need to carefully examine our responses as professionals to suicidal talk of our patients and to carefully assess if hospitalization is necessary or not. In many cases it is not, but fears of liability and risk pervade our profession.
We need to continue to de-stigmatize mental health concerns and embrace the recovery framework that has become mental health policy in many parts of the US following the U.S. President's 2003 New Freedom Commission on Mental Health that emphasized the need for a transformation of our nation's mental health system.

We need to embrace the position that people generally can get better, provide hope and afford quality mental health care to everyone.  Recovery also does not always mean a return to baseline functioning. This means we all need to become more tolerant of mental health symptoms, as long as the individual chooses to live with these symptoms and the person is not endangering him/herself or others.  It means we need to treat everyone with respect, empathy, and compassion.  We need to make it acceptable for someone with an acute exacerbation of, for example, debilitating anxiety to take a sick day at work for self-care or an emergency appointment with their treatment professional, and not having to lie and call in with a cold.

If we lose someone to suicide we need to stop "forcing” survivors to talk about their grief behind 
closed doors. Research has shown that survivors of suicide are treated differently than survivors of other deaths by other causes.  Specifically, the "societal perception that the act of suicide is a failure by the victim and the family to deal with some emotional issue and ultimately society affixes blame for the loss on the survivors"  is something that we can all work on to combat in our own lives.[ii]

While I am not saying or arguing that everyone who attempts suicide has a mental illness or mental health concern, it is undoubtedly true that many people that attempt or successfully completely suicide, do.  It is time that we talk more openly and urgently about this public health crisis.  We need to end the stigma that prevents so many people from at least attempting to seek help, especially in light of the many available treatments and avenues for help that are available.  This help can be gotten from a lot of sources; families, friends, clergy, suicide hotlines, therapists, and medical professionals.  We all play a role in this.  If you know someone who is not doing well, or you suspect may not be doing well, ask them how they are really doing today.

**If you are someone you know is struggling with thoughts of suicide get help now. Contact


**If you have lost someone to suicide, there is support. Contact


[i] Walen, S.  (2002).  It’s a funny thing about suicide: a personal experience.  British Journal of Guidance & Counseling, 30, 4, 415-430.
[ii] Cvinar, G. J. (2005). Do Suicide Survivors Suffer Social Stigma: A Review of the Literature. Perspectives in Psychiatric Care, 41, 1, 14-21.

Sunday, August 24, 2014

“Suicide by Cop” : What Do We Know About It and What Should We Do About It?

Petra Kottsieper Ph.D

A video has just surfaced of the events that lead to the shooting death of 25 year old Kajieme Powell in St. Louis. It is a very disturbing video to watch.  Initially, he is walking around the sidewalk seemingly muttering to himself, after he apparently stole two energy drinks from a convenience store that he had placed on the sidewalk. He ignores other people walking past him until the cops show up, who jump out of their car and very quickly draw their weapons. Mr. Powell is seen walking towards them and you can clearly hear him yelling at the police officers to shoot him, and they do. Apparently he was wielding a knife, which is not clearly visible in the video, and was threatening the officers.

People on the scene, as well as news writers, have been quick to call this a suicide by cop event. From what you can see and hear from the video, it could very well be. So what is suicide by cop? Suicide by cop (SBC) “ is a method of suicide that occurs when a subject engages in threatening behavior in an attempt to be killed by law enforcement” (Mohandie & Meloy, 2000). Usually this involves a subject brandishing a gun at police, both loaded and unloaded, which of course is an extremely dangerous situation for officers. 

SBC stats are not easy to come by, but several studies have attempted to arrive at some percentage of SBC of all police shootings.  One of the more recent studies published in 2009, found suicidal motivation accounted for 36 percent of more than 700 North American police shootings.[i]

These incidents have been around for a long time, but have not received scientific research attention until 1998.  Police departments and the FBI are also clearly aware of SBC, however, it is interesting to note that it was not until 1989 that the FBI began to track the number of justifiable homicides by police. Incidentally, a report from the Department of Criminal Justice, presents a large number of historical SBC case examples in their article.[ii]

Clearly calling a police shooting a SBC involves a clear and present danger to the responding officers. Most often this involves a firearm or what looks to be a firearm, but later turns out to have been a starter pistol or BB gun.  In the case of Mr. Powell; however, it was a knife.

It also requires the police to be aware that the person they are dealing with is actually suicidal and or mentally ill, and some kind of recognition of the behavioral or cognitive state of the person. This is of course not easy to tell, unless the person is yelling at the police to shoot them (which sadly occurred in the case at hand), or behaves in a very erratic manner.

Which brings me to one of my final points. Do police receive specialized training to deal with individuals who appear “erratic”, or may appear threatening either due to drug use or mental health problems?  And the answer is that indeed they do.

As early as 1974, forward thinking pioneers at Montgomery Country Emergency Service (MCES) in Norristown, PA started a training program where volunteer police officers were trained on mental illnesses and dual diagnosis (mental illness and substance abuse).[iii]  This was part of a pre-booking jail diversion training program.  This program was not started as a response to SBC, but rather as a response to the increasing arrest rates of people with mental illnesses for relatively low level offenses such as loitering, simple assault, trespassing etc. There are now numerous programs like this in the country, the best know being the Memphis CIT model (that is based on the local Montgomery Country, PA example). However, these programs fulfill the dual role of not only preventing unnecessary arrest and incarceration of individuals with mental illnesses, but also train officers of how to deal with individuals in crisis without resorting to force.

From their website: “The Memphis Crisis Intervention Team (CIT) is an innovative police based first responder program: 'This program provides law enforcement based crisis intervention training for helping those individuals with mental illness. Involvement in CIT is voluntary and based in the patrol division of the police department. In addition, CIT works in partnership with those in mental health care to provide a system of services that is friendly to the individuals with mental illness, family members, and the police officers.”[iv]

I do not envy police officers for the many challenges they have to face on a daily basis and the often ambiguous and dangerous aspects of their jobs. However, I also believe that the law enforcement community in every single jurisdiction in this country has a responsibility to implement something akin to CIT programs and/or to train all of their officers in how to deal with individuals in the community who may be mentally ill or high on substances; including those wanting to die at the very hands of the people sworn to protect them.  According to a NAMI CIT fact sheet, 2000 communities in more than 40 states have implemented these kinds of trainings for their officers and we can only hope that training on how to deal with individuals in crisis (including those with a mental illnesses) will be provided to all law enforcement officers everywhere in this country for everyone’s safety.  It will not bring back Mr. Powell, but it may help others who are dealing with a crisis they think they cannot overcome. It will also help the officers who are often emotionally scarred when realizing they may have unnecessarily taken a person’s life, realizing that they were dealing with a person with serious mental health problems and could have possibly responded in a different manner.


Thursday, August 21, 2014

How Does It Feel To Be A Problem?”

by Celine I. Thompson, Ph.D.

It is hard to have completed at least one course in African American studies without hearing DuBois’ question posed from The Souls of Black Folk.  A century later this same question dominates my thoughts about the recent Michael Brown shooting.  I think about my own brothers and male cousins and am thankful that such violence has not claimed them.  Unfortunately, my hurt and rage are not assuaged, because even though the urban, young, Black males closest to me have managed to skirt violent ends, nearly all of them have had encounters with law enforcement and the justice system before the age of 25.

 Additionally, they have lost peers to violence, incarceration, and have vicariously (if not personally) experienced unwarranted police surveillance and brutality in addition to other forms of violence in their communities.  Every time the media covers the shooting of a young unarmed Black male, my own anxiety increases as well as my concern for the physical and mental welfare of my loved ones.  However, I do not have the exact same ominous thoughts about my young female relatives, or for myself, although being Black and female has its own experiences and challenges.  For the most part I maintain the privilege of being able to walk down and across the street and not fear if a rolling cruiser will stop me on my way, and what might happen if it does.

However, Arizona State professor Ersula Ore cannot do just that at the college campus where she works, so it would seem that I should add to my list of things to be mindful of as a young Black woman the prospect of being arrested for jaywalking.  Although, I think I would have handled the situation differently from Professor Ore.  I probably would have done everything the police officer asked of me, given my ID, thoroughly explained what I had been doing in that area, mentally rewind and scan my last steps and actions in order to build a credible defense for any possible trial coming against me. I would feel the need to prepare and present my whole life story just to persuade the police officer that I had done nothing wrong, or if I did do something unlawful that I was not aware it and would have apologized immensely.  That would be my totally “warranted” response… for jaywalking.  And whether I was allowed to continue on my way or if I found myself sitting in the back of a police cruiser on the way to jail, I would feel useless.  I would feel powerless and hurt and scared and uncertain of what to do, if I could do anything.  If I did not know that I was perceived as a problem before such an encounter, I would definitely know what it felt like to be one.

Many young men in our city know how it feels to be a “problem.”  Two months ago I had the opportunity to sit in the audience of Alice Goffman, the author of the recently published book, On the Run: Fugitive Life in an American City.  She read a selection from her ethnography detailing the vulnerability of young Black males in encounters with law enforcement and the justice system of our dear city of brotherly love.  While listening to the stories Goffman shared, I reflected on the experiences of my own young male relatives and heard in her words what many will view as legitimate recognition of what it means to be young, Black, and male in Philadelphia in the 21st century.   Such vindication should be a relief, but in a room with a majority of educated women of color, you could feel tension and sorrow grow in our silence as Goffman spoke of the young men who were lost to violence and the struggles that many endure to try to steer clear of law enforcement for their own survival. 

It is the same tension and grief that I experienced in a conversation with a soon-to-be kindergartner. When I asked him if he was excited about going to a new school, he responded that he was a little “nervous.”   He continued to explain that “kids get locked up for fighting” at this school and if he was ever bullied, he was not sure if he could keep from fighting or getting into trouble.  I really wanted to tell him that he did not have to worry, but the most I felt that I could responsibly do was give him a few tips on how to deal with bullies.  The possibility of having to prepare a five year-old to deal with police officers is simultaneously distressing and surreal.

Perhaps these same emotions fuel the ongoing protests and riots in Ferguson as well as the peaceful protests observed throughout the country.  As psychologists experiencing such times and circumstances, we should be drawn to ask and search for answers to the following questions:  
  • How do developing young men manage these disproportionate and unfair experiences?
  • What “healthy” forms of parenting can take place under the threat of raising children so  undervalued in our society? 
  • And these captive young men, what can motivate them to strive for success under the     inescapable reality of how the world will view and treat them?

Charles Blow in a recent NY Times op-ed piece captured this sentiment in an equally poignant version of the question posed by DuBois:“What psychic damage does it do to the black mind when one must come to own and manage the fear of the black body? The burden of bias isn’t borne by the person in possession of it, but by the person who is the subject of it.”

My mentor, Dr. Howard Stevenson, Constance E. Clayton Professor at Penn, has worked to help Black families manage this misplaced burden.  His work helping Black boys manage anger and racial stress in schools and to help African American families raise children in an environment affected by racism has brought attention to these issues and provides families with information and guidance on promoting resilience in our youth.  As mental health professionals, we need to be aware of and familiar with research literature and resources available to guide our understanding and treatment of the issues that affect vulnerable youth and those who are responsible for their care and survival.  For a soon-to-be kindergartner it cannot begin soon enough.

Dr. Celine Thompson is an Assistant Professor in the Clinical PsyD program.  Dr. Thompson obtained her PhD in Interdisciplinary Studies in Human Development from University of Pennsylvania Graduate School of Education, where she also completed her Master’s degree in Psychological Services (currently known as Counseling and Mental Health Services).  Her dissertation research focused on understanding “racially-gendered” identity development processes in Black adolescent females.

Tuesday, July 1, 2014

Not Sorry I'm Not Sorry

Jessica Glass Kendorski, Ph.D

Pantene's recent commercial depicting women apologizing for being assertive has been getting lots of attention from national media outlets such as Good Morning America and ABC News.  In the ad, several women are seen saying “I’m sorry” in situations that clearly don’t call for it—for example, one woman apologizes for interrupting a business meeting, and another apologizes for handing her husband their child after he comes home from work.

The ad comes at an opportune moment; this week, President Obama is hosting the first-ever White House Summit on Working Families, which will address improving gender equality on the workplace. In light of all of this, I wonder if gender differences in communication account for some of that disparity.

Women make up 47 percent of the work force. Working married women bring home 44 percent of their family’s income, and women make up 59 percent of the recipients of college degrees. Yet women only earn 77 cents for every dollar earned by men.  Could the tendency for women to constantly apologize, and engage in less assertive communication, be a possible contributor to this wage gap?

Expectations are key. Expectations guide communication in the workforce and also guide how adults communicate to impressionable children. Men are expected to ask for what they need and women are expected to apologize for asking. Fostering equal environments in the workforce begins with fostering equal expectations for men and women—starting in early childhood.

Early on, girls are taught to stifle displays of negative emotions such as anger and frustration, and often express the opposite of what they’re feeling, such as smiling even though they’re not happy—and apologizing when they’re not sorry.  On the other hand, it is more acceptable for boys to show evidence of anger and frustration. Because boys can externalize their feelings, they are able to learn to express these behaviors appropriately through assertive communication. If girls continuously suppress their emotions, then they may never learn how to truly be assertive.

Regardless of gender, children experience intense emotions and need to be supported and taught appropriate ways of dealing with these emotions. Adults should be aware of their expectations and the behavior these expectations foster in children.  Boys are expected and taught to grow up strong and assertive, but girls should be taught the same. And as the Pantene commercial shows, women can find strength in the ability to truly express their feelings.
Chaplin, T.A., Aldao, A. (2013). Gender difference in Emotion Expression in Children: A Meta-Analytic Review. Psychological Bulletin, 139, 4, 735-765.