Handedness and sex roles: Mixed-handers are less sex-congruent stereotyped

Previous research reported that non-right-handers display a less sex-congruent stereotyped sex-role identity (i.e., women portray themselves as more masculine, men as more feminine) than right-handers. However, classification of handedness was based on arbitrary criteria and did not distinguish between left-handedness and mixed-handedness among non-right-handers. We present data from two large and independent middle-European samples, a discovery (n= 7658) and a replication (n= 5062) sample. Using latent class analysis for handedness classification, it is shown that mixed-handedness, rather than left-handedness, is the driving factor underlying associations between handedness and sex-role identity. We discuss our findings with regard to the Geschwind-Galaburda theory of cerebral lateralization and the need to evaluate the contribution of sexual orientation on this association in future research.