Shashwat Goyal
4th blog post
ASPD shows a gender
skewed occurrence humans, occurring roughly 6 times more often in men than
women (Smith, 2018) and with a
prevalence ratio of 3:1 for men versus women (Alegria et al., 2013). What could be
causing this gender skewedness? This post will look at the possible theories
explaining this, ranging from diagnostic bias to evolutionary theory.
ASPD is defined as “A pervasive pattern of disregard for and
violation of the rights of others, occurring since age 15 years” (The Diagnostic and Statistical Manual of
Mental Disorders, 1994). It often manifests with symptoms like violent
behaviour, lack of empathy and impulsive behaviour. 80 percent of ASPD
patients show symptoms by age 11 (Smith, 2018), which suggests
either a genetic basis or a strong effect of early childhood. As the stress
diathesis model tells us, it is both.
What is the reason that
women are underrepresented in ASPD figures, are they less susceptible to ASPD?
The simplest answer is perhaps that they are no less susceptible, but are
rather misdiagnosed or remain undiagnosed due to societal gender roles as well
as symptomatic presentation. A report showed that doctors are more likely to
diagnose women with depression compared to men even with the same scores on
standardized tests or similar symptoms (“WHO | Gender and women’s mental health,” 2013). Another article
expounds that there are reporting biases in men and women (Briggs, 2000). While they may
not refer to ASPD, they certainly shows that gender roles cause diagnostic and
reporting biases that could affect ASPD diagnosis rates. Another factor is that
women with ASPD often show non-violent manifestation/behaviour compared to men
(for eg. missing classes vs. starting fights) (Alegria et al., 2013), which could contribute
to misdiagnosis of women with ASPD.
However, let’s consider
for a moment that the gender skewedness persists after accounting for the
biases. Another possible theory is that there’s an evolutionary advantage for
men to display behaviour seen in ASPD. This theory assumes at least a partial
genetic basis of ASPD. In organisms where the females gestate the progeny,
males are subject to intrasexual competition with other males for mating with
females. In this case, being more violent, aggressive, and displaying other
typically masculine traits are considered advantageous for the male competing
with other males. In a community without rules like ours, ASPD symptoms may
help an organism be the dominant male in the community, thereby securing mating
with females and thus siring more progeny with ASPD alleles.
However, we live in a
society with rules, and ASPD patients have low lifespans due to substance
abuse, crime, etc. (Smith, 2018). So why is ASPD
increasing in frequency (Eddy, 2018) and not slowly
being removed from the population (as its alleles would be selected against).
One answer could be that the mutation(s) that cause(s) the allele(s)
responsible for ASPD are common. However, mutations are generally rare and a
better explanation can be that it still has a benefit.
One theory to explain
this benefit would be a stress diathesis model. The nurture part of ASPD can’t
be ignored as it is clearly correlated with early childhood neglect, abuse, adversity,
etc. (Alegria et al., 2013). Hence, consider
a stress diathesis model where certain genes that give vulnerability to ASPD
might be naturally selected for since they allow the organism to respond with
violence and protect itself from a hostile environment (as exemplified by
abuse, adversity, etc.). This would also make sense from the perspective that
hyper aggressive individuals are more likely to get injured or die, thereby
reducing the benefit of ASPD for individuals living in a relatively less
hostile environment. The fact that women display higher resilience to risk
factors and show less violent manifestations of ASPD (Alegria et al., 2013) also supports
this, as females don’t face the intrasexual competition that males do and
instead focus all their energy on producing healthy progeny. Thus, in this
case, the stress diathesis model itself is an adaptive feature.
The last explanation (in
lieu of this post) for a possible benefit manifestation of ASPD symptoms in
males can be that women prefer aggressive, typically masculine males (Giebel, Weierstall, Schauer, & Elbert, 2013;
Puts, 2010; Snyder et al., 2011), which ties into
the intrasexual competition in males.
As one might notice, all
these theories are dependent on ASPD having an appreciable genetic basis at the
very least, which it does (Alegria et al., 2013). However, the
action of environment, while demonstrated, needs to be clarified fu rther to assess whether the reason
for ASPD’s gender skewedness is evolutionary or if it is an artefact of our
social structure and/or biological development.
References
Alegria, A. A., Blanco, C., Petry, N. M., Skodol, A.
E., Liu, S.-M., Grant, B., & Hasin, D. (2013). Sex differences in
antisocial personality disorder: results from the National Epidemiological
Survey on Alcohol and Related Conditions. Personality Disorders, 4(3),
214–222. https://doi.org/10.1037/a0031681
Briggs, L. (2000). The Race of Hysteria: Overcivilization and
the Savage in Late Nineteenth-Century Obstetrics and Gynecology. American
Quarterly, 52(2), 246–273. https://doi.org/10.1353/aq.2000.0013
Eddy, B. (2018). Are Narcissists and Sociopaths Increasing? |
Psychology Today. Retrieved May 4, 2019, from
https://www.psychologytoday.com/intl/blog/5-types-people-who-can-ruin-your-life/201804/are-narcissists-and-sociopaths-increasing
Giebel, G., Weierstall, R., Schauer, M., & Elbert, T.
(2013). Female attraction to appetitive-aggressive men is modulated by women’s
menstrual cycle and men’s vulnerability to traumatic stress. Evolutionary
Psychology : An International Journal of Evolutionary Approaches to Psychology
and Behavior, 11(1), 248–262. Retrieved from
http://www.ncbi.nlm.nih.gov/pubmed/23531810
Puts, D. A. (2010). Beauty and the beast: mechanisms of
sexual selection in humans. Evolution and Human Behavior, 31(3),
157–175. https://doi.org/10.1016/J.EVOLHUMBEHAV.2010.02.005
Smith, K. (2018). Antisocial Personality Disorder
(Sociopathy): Causes and Symptoms. Retrieved May 3, 2019, from
https://www.psycom.net/antisocial-personality-disorder/
Snyder, J. K., Fessler, D. M. T., Tiokhin, L., Frederick, D.
A., Lee, S. W., & Navarrete, C. D. (2011). Trade-offs in a dangerous world:
women’s fear of crime predicts preferences for aggressive and formidable mates.
Evolution and Human Behavior, 32(2), 127–137.
https://doi.org/10.1016/J.EVOLHUMBEHAV.2010.08.007
The Diagnostic and Statistical Manual of Mental Disorders. (1994) (Fourth edi). Association, American Psychological.
WHO | Gender and women’s mental health. (2013). WHO.
Retrieved from https://www.who.int/mental_health/prevention/genderwomen/en/
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