There is a direct relationship between nonverbal intelligence and serum testosterone level in young men

It was confirmed that there is a direct relationship between serum testosterone level and nonverbal intelligence (Cattel's Culture Fair Intelligence Test) only in right-handed male subjects without familial sinistrality (FS-), with right eye preference. There was no significant correlation between these variables in young women and young men with mixed eye preference. It was concluded that testosterone would be an important factor which affects cognitive development in men.