Stereotypes and steroids: Using a psychobiosocial model to understand cognitive sex differences

To further our understanding of cognitive sex differences, we studied the r elationship between menstrual phase (via serum estradiol and progesterone l evels) and cognitive abilities and cognitive performance in a sample of med ical students in eastern Turkey. As expected, we found no sex differences o n the Cattell "Culture Fair Intelligence Test'' (a figural reasoning test), with females scoring significantly higher on a Turkish version of the Find ing A's Test (rapid word knowledge) and males scoring significantly higher on a paper-and-pencil mental rotation test. The women showed a slight enhan cement on the Finding A's Test and a slight decrement in Cattell scores dur ing the preovulatory phase of their cycle that (probably) coincided with a rise in estrogen. There were also small cycle-related enhancements in perfo rmance for these women on the mental rotation test that may reflect cyclica l increases in estrogen and progesterone. Additional analyses showed an inv erted U-shaped function in level of estradiol and the Cattell Test. Finally , for women who were tested on Day 10 of their menstrual cycle, there was a negative linear relationship between their Cattell scores and level of pro gesterone. Stereotypes about the cognitive abilities of males and females d id not correspond to performance on the mental rotation or Finding A's Test . so the sex-typical results could not be attributed to either stereotype t hreat or stereotype activation. For practical purposes, hormone-related eff ects were generally small. Variations over the menstrual cycle do not provi de evidence for a "smarter'' sex, but they do further our understanding of steroidal action on human cognitive performance. (C) 2001 Academic Press.