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A discussion of psychological and neurological factors contributing to the differences in susceptibility to psychopathy.
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SEX DIFFERENCES IN PSYCHOPATHY what accounts for such “expected” observation?
There are more male psychopaths than female psychopaths, with the former making up a greater proportion of criminal offenders. • Can sex-related neuropsychological differences between men and women adequately explain such fact and finding?
EVIDENCE FROM THE BRAIN • Less gray matter and connections in the amygdala region observed in psychopaths. • So how does this finding relate to differences between male and female brains?
BRAIN AMYGDALA VOLUME • The amygdala region is involved in processing affective stimuli, especially fearful ones. However, contrary to expectation, women do not necessarily possess a bigger amygdala than men.
NEVERTHELESS, VOLUME DOES NOT EQUAL RESPONSE/FUNCTION • Women research subjects demonstrated greater amygdala responses than men. Such responses pertained particularly to fearful stimuli (Hofer et al., 2006)
On the other hand, men reacted more strongly to positive emotional stimuli(not surprisingly), yet still involving the amygdala region.
SIMILAR VOLUME CAPACITY, BUT A SEX-DIFFERENTIATED IMBALANCE IN RESPONSE INTENSITY • Women exhibited stronger negative response to negative, especially fear-related, stimuli than men.
So, does fear hold the key to sex differences in psychopathy? • The answer probably lies in the physiological and evolutionary bases that contribute to such structural and functional brain outcomes…
FACT: PHYSICAL AND PHYSIOLOGICAL DIFFERENCES BETWEEN MEN AND WOMEN ARE REAL AND INNATE. • Women, though not necessarily weaker than men, still possess smaller body size, which explains why they have a smaller brain, and thus amygdala, volume than men. Nevertheless, smaller amygdala volume still spells greater response to fearful stimuli, against all odds.
GREATER FEAR: PROTECTIVE OR ofFENSIVE? • From an evolutionary point of view, there is a function for fear in women – to protect themselves from physical harm and oppression (due to their less advantageous body size), from even probably the opposite sex. In this way, fear has a protective value. Yet, men do not naturally benefit from such a value, thus they have no reason to fear or be strongly reactive to fearful stimuli. On the other hand, the utility of fear to them is most probably to increase their offensive stance in the face of competition for resources.
So, it seems… • Fear can be one of the many parts of puzzle linking evolutionary and neurodevelopmental explanations for sex differences in psychopathy.
Take-home message: When there is a reason to fear, please do not suppress it!