Volume 37, Issue 4, July 2016, Pages 323–336
Abstract
Baron-Cohen's
‛extreme male brain’ theory postulates that autism involves exaggerated
male-typical psychology, with reduced empathizing (considered here as
social–emotional interest, motivation and abilities) and increased
systemizing (non-social, physical-world and rule-based interest,
motivation and abilities), in association with its male-biased sex
ratio. The concept of an ‘extreme female brain’, involving some
combination of increased empathizing and reduced systemizing, and its
possible role in psychiatric conditions, has been considerably less well
investigated. Female-biased sex ratios have been described in two
conditions, depression and borderline personality disorder (BPD), that
also show evidence of increases in aspects of empathy in some studies.
We evaluated the hypothesis that BPD and depression can be
conceptualized in the context of the ‘extreme female brain’ by: (1)
describing previous conceptualizations of the extreme female brain
model, (2) reviewing evidence of female-biased sex ratios in BPD and
depression, (3) conducting meta-analyses of performance on the Reading
the Mind in the Eyes test (RMET) among individuals with BPD, clinical or
sub-clinical depression, and other psychiatric conditions involving
altered social cognition and mood (schizophrenia, bipolar disorder,
eating disorders, and autism), in relation to disorder sex ratios, and
(4) evaluating previous evidence of increased empathic performance in
these, and related, psychiatric conditions, and (5) synthesizing these
lines of evidence into models for causes and effects of an ‘extreme
female brain’. Our primary empirical results are that RMET performance
is enhanced in sub-clinical depression, preserved in borderline
personality disorder, and reduced in other disorders (by meta-analyses),
and that across disorders, more male-biased patient sex ratios are
strongly associated with worse RMET performance of patients relative to
controls. Our findings, in conjunction with previous work, suggest that
increased cognitive empathizing mediates risk and expression of some
psychiatric conditions with evidence of female biases, especially
sub-clinical depression and borderline personality disorder, in
association with increased attention to social stimuli, higher levels of
social and emotional sensitivity, negative emotion biases, and
over-developed mentalist thought. These results link evolved human sex
differences with psychiatric vulnerabilities and symptoms, and lead to
specific suggestions for future work.
Keywords
- Empathizing;
- Female brain;
- Autism;
- Depression;
- Borderline personality
© 2016 Elsevier Inc. All rights reserved.
