A New Kind of Twin Study and the Heritability Fraud

In my post on Psychology Today, "Scientific Fraud in the Nature versus Nurture Debate," I discussed the disturbing tendency of psychiatric researchers to use the term heritability as a synonym for genetic, which it certainly is not. The heritability statistic is a measure of phenotype, not genotype, meaning it is a measure of the final outcome of the influence of the interactions between genes and the environment on such things as certain personality characteristics or psychiatric symptoms.

The statistic is derived from twin studies in which fraternal and identical twins who were raised together are compared to each other and to those raised apart on various traits. It is not a measure of purely genetic influences but instead a measure of a mix of purely genetic influences plus gene-environment interactional influences. 

There is no way to tell how much of each is present in the statistic. The determination of heritability can also be manipulated in a number of ways, such as by setting the bar for saying that a symptom is present or absent at different levels.

Interestingly, a recent study employing a very different type of twin study has been getting a fair amount of press (Thalia C. Eley, Tom A. McAdams, Fruhling V. Rijsdijk, et. al., "The Intergenerational Transmission of Anxiety: A Children-of-Twins Study," American Journal of Psychiatry, 172 [7], pp. 630-637, 2015).

Rather than comparing twins with each other, the authors compared the children of twins with one another. The subjects were anxiety and a dimension of normal personality known as neuroticism - a measure of emotional reactivity. People with higher neuroticism scores tend to get more anxious and/or depressed in reaction to negative environmental stimuli, and remain dysregulated longer, than those with lower scores.

By comparing the extent to which correlations between children and their twin uncle/aunt (avuncular correlations) differ for monozygotic (identical) and dizygotic (fraternal) twin families, the authors were able to infer the extent to which genetic and environmental factors influence transmission from one generation to another. Children share a greater level of genetic influence with their uncle/aunt when in monozygotic families than when in dizygotic families.

Thus, if children resemble their uncle/aunt to a greater extent in monozygotic families than in dizygotic families, this implies a genetic influence on transmission of the trait of interest. In contrast, if these two sets of correlations are similar, and are significantly lower than the parent-child correlations, this is indicative of an environmental mode of transmission.

The results of the new study showed almost the opposite of the usual results of heritability studies on neuroticism: environmental factors came out very much more important than genetic ones! Living with one's parents was found to be far more influential than merely inheriting 50% of their genes.

It appeared that children and adolescents learned anxious behavior from their parents rather than inheriting a tendency towards it from their parents genetically.

Now, I must say that the authors used a statistical technique to come to their conclusion called "structural equation modeling"—of which I know absolutely nothing. So I am not able to say if the methodological techniques used in traditional twin studies yield more accurate results than those found in this type of study. This may, in fact, be a case of scientists being able to get the results they want to get through statistical manipulation of their study data.

And surely neuroticism must have some significant genetic component. Clearly, some people are naturally more high strung than others.

Nonetheless, I do know from the observation of blatantly obvious behavioral patterns within families and other social groups that anxiety can be highly contagious. Since as of now mental health professionals can't fix your genes but we can fix your relationships, I know on which factors therapists should focus the majority of their attention.

Performance versus Ability: Another Issue Frequently Ignored in Psychiatry Research

In previous posts, I have discussed some bizarre assumptions made in psychiatry research papers when the data is analyzed. I wrote about how, for example, differences in brain area size and functioning between different groups on fMRI scans are automatically interpreted as abnormalities.

Nassir Ghaemi, a blogger on Medscape with whom I have had some strong disagreements about borderline personality disorder and bipolar disorder, nonetheless had a great quote on this with which I wholeheartedly agree:
             

"All things biological are not disease, even though we can define disease in such a way that all diseases are biological. This matter is obvious once pointed out. A few assumptions,  which seem either patently true or very likely: all human psychological experience is mediated by the brain; each person only has one brain; therefore the brain will always be biologically changing as we have psychological experiences. Reading a blog post about the brain is a psychological experience. Having delusions from schizophrenia is a psychological experience. The first brain change does not reflect disease; the second does. So showing MRI changes with adult ADHD or borderline personality does nothing to demonstrate that those conditions are diseases. If you watch TV and play video games inordinately, you will have changes in your brain, and you might also develop clinical symptoms of ADHD. If you are repeatedly sexually abused, you will have changes in the brain, and you might also develop clinical symptoms of borderline personality. But those changes in the brain do not have the same causal role as the neuronal atrophy that happens with trisomy 21, or with schizophrenia, or bipolar illness..."

Another major nonsensical assumption that litters the psychiatric literature (the literature littering alliteration?) is that one can totally disregard the motivations of research subjects as well their past experiences and the environmental context in which they live when evaluating their performance on psychological tests. 

I mentioned an example of how this is utter nonsense in a previous post: The performance of African-Americans on IQ tests just might be related to the fact that for several generations Blacks who looked too smart were at high risk of being lynched. Do you think they are just as motivated as other folks to want to look smart on an IQ test which is being administered by White researchers?

What I have seen more and more lately, particular in the personality disorders literature, are studies that look at differences between various diagnostic groups on such issues as how much "impulsive aggression" they show, or how and how well they read the emotional state of ambiguous faces of strangers in photographs. When differences are found, once again the "lower" performing groups are just assumed to be "impaired" or "abnormal."

This, of course, confuses performance with ability. Without knowing anything about what the subjects in the experiments are motivated to do in their daily lives on any particular dimension for whatever reason, or what environmental contingencies they are worried about that may relate to the task at hand, it is literally impossible to say for sure whether any difference in their performance is related to what they would be able to do if those other issues were not operative.

Patients with borderline personality disorder, for example, grow up in families in which double messages are flying in all directions, and with parents who can switch from being over-involved to neglectful at the drop of hat. They are bound to have a higher index of suspicion about what facial expressions on strangers might mean than someone who grew up in a more consistent and predictable environment. If they did not, they would be morons.

Another major issue ignored in the literature is the difference between a research subject's real self versus their persona or false self in certain social situations. We all present different "faces" to the outside world depending on social context. Researchers who do not consider this must think that men, for example, present themselves exactly the same way around their children, their bosses, and their mistresses. Really?

With personality disorders, as I described in several previous posts, people play social roles designed to stabilize family homeostasis. These roles are merely a much more pervasive version of the different roles played by the above "normal" man interacting with different people. So someone with antisocial tendencies, for example, which are part of the role of avenger, are motivated to show more impulsive aggression than other people - on purpose - and have literally trained themselves to be like that. They do so habitually, automatically, and without thinking. Of course they will show more impulsive aggression in the experiment! Why wouldn't they? 

In fact, showing a lot of impulsive aggression might be considered to be part of the definition of antisocial behavior. The experiments therefore do nothing more than prove that anti-social people act habitually in an anti-social manner. Like, duh!

These types of results in no way indicate any "deficits," "deficiencies," or "abnormalities." One wonders how people who make these ludicrous assumptions ever manage to get through medical or graduate school.

Dr. Allen's Second Book Back in Print

My second book, Deciphering Motivation in Psychotherapy (which was originally going to be titled Ulterior Motives) is now available in paperback at a reasonable price on Amazon for the first time. It is actually my favorite of the ones I've written, but by far the least read.

It was out of print for a time, and then back out but at a ridiculous price. (A different publisher had bought out the original publisher, then re-published the book without even letting me know!)

It was meant for therapists but is written so lay people can understand it.

This book explains some basics about the theory behind Unified Therapy, including the core concept of dialectic causality.

The main topic is the use of language in dysfunctional family interactions, and how the true intentions and meanings of individuals who are being ambiguous or misleading can be discovered. If you want to see things that have been said to you repeatedly by difficult relatives in a whole new and surprising light, this is the book for you!