A test of the X-linked genetic hypothesis for sex differences on Piaget's water-level task

Data from seven studies involving 849 high school and college students were used to test the recessive X-linked genetic model prediction that the square of the proportion of men who perform accurately on the water-level task is equal to the proportion of women who perform accurately. Goodness-of-fit tests showed that this prediction was confirmed for each sample. A model with a single estimate of gene frequency accounted for all the data when a classification error parameter was incorporated into the X-linked model. In both models the gene frequency parameter was about $\text{2}\text{3}$.     

Dichhaptic laterality and field dependence

Relationships among laterality, field dependence, and sex were investigated using right handed subjects. Dichhaptic measures of laterality showed a significant left-hand advantage for the discrimination of irregular shapes. No significant relationships were found between laterality and sex or sex role perceptions nor between laterality and field dependence. A modality of response effect on the laterality task was interpreted in terms of the functional cerebral space principle.