Empathizing, systemizing and finger length ratio in a Swedish sample

Abstract

The Empathy- and Systemizing Quotients (EQ and SQ, respectively; Baron-Cohen, 2003) were determined in a Swedish sample consisting mainly of university undergraduates. Females had significantly higher EQ than males, who in turn scored higher on the SQ inventory. Gender explained 12-14% of the variation. Males were strikingly overrepresented in the group defined by a high SQ/low EQ profile or by a large SQ - EQ difference; females dominated among people with a low SQ/high EQ profile or by a large EQ - SQ difference. Students majoring in the natural sciences had higher SQs than psychology majors, but in both groups the gender difference in SQ and EQ was strong. For each participant a weighted composite score was generated by multivariate processing of the EQ and SQ data (Partial Least Square Discriminant Analysis). These scores were associated in a sex-linked fashion to a biometric measure reflecting prenatal testosterone exposure, i.e. the ratio between index (2D)- and ring (4D) finger lengths. In males a high (female-typical) 2D:4D ratio predicted an enhanced tendency to empathize and a reduced tendency to systemize; in women, by contrast, the 2D:4D ratio was unrelated to these traits. The present research confirms earlier work of a gender difference in EQ and SQ. The difference appears robust as it appears as large in Sweden (a country with high cultural gender-equality) as in countries with considerably lower gender-equality.