This is Part 3 of the round-up of evolutionary-clinical psychology presentations at the Human Behavior and Evolution Society’s 2012 conference; See Part 1 and Part 2 first, for a full appreciation of the plot and characters!
On Sunday morning, the last day of the conference, there was an entire session devoted to evolutionary perspectives on psychopathy. The talks were held in the Lobo Room, which is named for UNM’s lupine mascot, not for the DC Comics anti-hero/villain bounty hunter –who also just so happens to be a psychopath.
First up, Daniel Krupp from Queen’s University presented a neat talk on whether psychopathy is a disorder or an adaptation. Woah, wait, let’s hear him out on this one!
Krupp is using Jerome Wakefield’s definition of “disorder,” which states that a true disorder must be both harmful to an individual and/or society, and also represent a dysfunction in a naturally selected mechanism. Any condition that does not conform to the harmful dysfunction definition, says Wakefield, should not be considered a disorder. For example, if left-handedness were found to be due to a glitch in brain development and organization, it should not be considered a disorder because it is not harmful (and thus, our society was wrong to treat it as such back in the day when lefties were “cured” by being forced to use their nondominant right hand). Similarly, mild acrophobia (fear of heights) might not be considered a disorder because it is a naturally selected mechanism functioning normally to keep us away from dangerous high places–it just so happens it’s inconvenient in our modern environment of skyscrapers and airplanes.
Since morality and a “conscience” (i.e., an internal sense of what is “right” and what is “wrong” to do to others) have recently been viewed in evolutionary psychology as adaptations to social life which gave our species a benefit, evolutionists have often viewed psychopathy as a disorder because it is harmful to society (the reason it was considered a disorder even before the advent evolutionary perspectives) and seemed to represent a dysfunction in a naturally selected “Empathy” or “Conscience” module. Krupp challenges this view by asking whether psychopathy is truly harmful AND whether or not it is actually a dysfunction.
He raises the possibility that the cruel, manipulative behavior of psychopaths, which is highly heritable, may be a type of frequency-dependent evolutionary strategy. A small enough number of psychopaths in a group may have a genetic advantage, Krupp suggests (although morality, by virtue of having evolved at all, has proven to be a more stable strategy for an entire human group than everyone being psychopathic). To support this claim, Krupp contrasted the fact that people with other severe mental disorders (such as bipolar mania and schizophrenia) tend to harm or kill their genetic relatives, while those with antisocial personality disorder are much more likely to harm nonrelatives – potential evidence of design.
While I was intrigued by the presentation, I’m not convinced just yet. Dr. Krupp meant his research as the starting place for future inquiry, and was not definitively claiming to be correct. Keep in mind that even if psychopathy increases genetic fitness (and even if it could have done so in an ancestral environment, where it was harder to get away with such behavior without being immediately ostracized or killed), if it is underlied by a neurological abnormality (e.g., biochemical or cortical irregularities), there may be a case to be made for the dysfunction portion. Even if no consistent physical substrate of psychopathy is identified (Krupp suggested there was little evidence of such markers, while the next speaker suggested that there was), psychopathy could still be a dysfunction under Wakefield’s definition.
But there’s another factor here which merits comment – in fact, merits its own discussion in a future post. Krupp and others in the room suggested that Wakefield’s harm criterion could be met by an impediment to one’s genetic success, and thus gaining a genetic benefit from, say, psychopathic behaviors would negate the harm criterion. However, Wakefield (1992) views his definition of “harm” as relating to both personal and societal interests; a person who harms others – regardless if he is simultaneously benefitting his own genes – would thus still meet the harm criterion; in his 1992 paper Wakefield goes so far as to clearly distinguish between a trait being evolutionarily useful (i.e., conferring genetic success) and being presently socially valued — with the latter being the intended target of his “harm” component.
Since an evolutionarily informed alternative to the DSM has not yet been assembled (see my post here), there is no final arbiter as to which definition of “disorder” is the “right” one. Perhaps genetic success should be considered the (or part of the) bottom line when interpreting “harm,” as many of the experts in the room believed; perhaps such a construal would be atrocious for the field of clinical psychology. I don’t know, and it’s an open question which deserves much thought. At any rate, it seemed to me that a pure genetic construal of Wakefield’s harm criterion was different than what Wakefield himself had in mind, and that’s fine, but nobody in the room acknowledged this distinction (including myself…it took me some time to wrap my head around the issues enough to form cogent thoughts).
Next, Elsa Ermer took the opposite position from Krupp and suggested that psychopathy was a dysfunction rather than a social exploitation adaptation, basing her claims on cognitive neuroimaging studies of prisoners. I was saddened that Dr. Krupp had to leave before this talk to catch a plane, meaning that we did not get to hear a dialogue between the two.
Psychopaths, it seems, perform worse on social judgment tasks – a true impairment in cognition, Ermer suggested. While this finding would not be incompatible with an adaptation argument, neuroimaging showed structural deficits in areas related to social and emotional processing which are present as early as adolescence, which, Ermer claims, is more suggestive of a neurodevelopmental disorder than it is of an adaptation. Yes, I paraphrased this paragraph from the program abstract, because I wasn’t able to successfully jot down the many differences in particular brain regions between psychopathic and non-psychopathic prisoners. Anybody who can flesh this out, please do!
Finally, Joseph Manson from UCLA discussed the possibility that psychopathy may represent high levels of psychopathic-type traits on a continuum; individuals with subclinical levels of traits like callousness may be able to deploy selfish strategies conditionally and adaptively. Rather than indiscriminately being cruel to everyone, Manson suggests that individuals with moderate levels of psychopathic traits should cooperate when it benefits them, and only defect when they get no benefit from cooperation. Manson and colleagues tested this model with a one-shot prisoner’s dilemma game; they tested students’ levels of psychopathic type traits, and also allowed the subjects to chat with each other before the games were played. These interactions were filmed and coded for a number of variables, including how frequently participants interrupted each other and how much common ground they were able to find with each other (e.g., similar majors). Consistent with the “contingency model” of subclinical psychopathic behavior, individuals who were high on so-called Factor 1 psychopathy traits (callous affect and interpersonal manipulation) were more likely to defect against partners who had interrupted them and with whom they had little in common. This study may offer a different type of adapationist perspective of psychopathy: rather than clinical levels of psychopathy being selected for, they may simply be the distributional extremes of behavioral patterns which normally function to conditionally reap benefits at others’ expenses, based upon the circumstances.
The fourth scheduled presenter had canceled, so an informal discussion session ensued. With apologies to all present, this discussion was fascinating but none of the concepts raised struck me as earth-shattering, so I shan’t cover them here.
Join me in a week or so (maybe) as I discuss several talks and posters which I didn’t get to see, but which were of relevance to clinical and evolutionary psych!