Spatial cognition in rhesus monkeys: Male superiority declines with age

Twelve young (4-7 years of age) and 14 old (20-27 years of age) male and fe male rhesus monkeys were tested on seven cognitive tasks. Males and females performed similarly on tasks of object memory and executive function, but young males outperformed young females on a spatial memory task (Delayed Re cognition Span Test) that requires the identification of a new stimulus amo ng an increasing array of serially presented stimuli. This superior level o f spatial ability in young males declined sharply with age, so that old mal es did not perform significantly better than old females. These findings in the nonhuman primate suggest that biological rather than sociocultural fac tors underlie the sex differences in cognition and their diminution with ag e. (C) 1999 Academic Press.