Cognitive styles sex the brain, compete neurally, and quantify deficits in autism

Introduction: Two key dimensions of the mind are understanding and responding to another's mental state (empathizing), and analysing lawful behaviour (systemizing). Methods: Two questionnaires, the Systemizing Quotient (SQ) and the Empathy Quotient (EQ), were administered to a normal control group and a group of individuals with Asperger Syndrome (AS) or High-Functioning Autism (HFA). The multivariate correlations of the joint scores were analysed using principal components analysis. Results: The principal components were well-approximated by the sums and differences of the SQ and EQ scores. The differences in the scores corresponded to sex differences within the control group and also separated out the AS/HFA group, which showed stronger systemizing than the control group, but below-average empathy. The sums of the scores did not show sex differences, but did distinguish the AS/HFA group. Conclusions: These tests reliably sex the brain, and their correlations show that empathizing and systemizing are not independent, but compete neurally. Their combined score (EQ + SQ) quantifies the deficit in autism spectrum conditions.