Who or what is responsible for sex caused differences in brain structure and functioning: our biological inheritance or is it simply the consequence and the result of learning, experience and socio cultural influence? Scientists with different approaches and different orientation agreed in one: responsibility for sex caused differences of cognitive capabilities share innate (genes and hormones) and acquired (experience and learning) factors.

Studies which consider cognitive abilities males and females are mostly done with heterosexual and homosexual individuals. The aim of this study was to asses some aspects of cognitive functioning of female-male transsexuals (FMT) and to compare it with the model of functioning of heterosexual female (HF) and male (HM) individuals.

Experimental group consisted of seven FMT and 14 individuals were in HS group (seven in each, HM and HF). FMT were in stage of preparation for operative treatment, and transsexualism was diagnosed and guided within this program. We used Thurstone Test of Verbal Fluency as a written test for word fluency.

The results showed that in the first part of the test (words starting with S) F-M transsexual group was the worst, and in the second part of the test (words with 4 letters starting with K) they had the score closer to homosexual females. Higher score in the last minutes in both parts of test had the group of F-M transsexuals and male heterosexuals. This could be interpreted as an outcome of better attention of individuals in these groups.