Sex and Gender

Experiment: Developmental Gender Study

Some of the most basic differences between the sexes are revealed at a very young age. These findings raise a central question: Are gender differences and behaviors learned or innate? Developmental neuroscientist Dr. Michael Meaney of McGill University studied the gender roles in young vervet monkeys and Norway rats at play.

From a very young age, the male and female rats and monkeys engaged in different forms of play. Males were involved in vigorous forms of physical play, while females engaged in equally social but quieter activities, such as grooming and tending to infants. Dr. Meaney found that these distinctions in how male and female animals play often parallel the common behavior of young boys and girls. Human gender roles manifest themselves early in childhood in the form of motor activities, with boys generally tending to choose gross motor activities, and girls discreet, finer ones.

The relationship between hormonal changes and environmental events helps explain this pattern of gender behaviors. Male and female sex hormones cause different reactions in the brain, affecting the behavior of an individual, which in turn affects his or her experiences. From a very young age, a biological and psychological cycle develops and continues into adulthood.

Forms of play are the building blocks for psychological and physical behavior as children mature into juveniles, adolescents, and adults. The fact that the same gender patterns form universally throughout the animal kingdom suggests that certain psychological sex distinctions are innate. When certain behaviors are qualified within social contexts and given negative or positive attributes, they become stereotypes that can constrict or expand human possibilities and alter our world.