the interaction of genetic and environmental influences.”

an early school of thought in psychology that used introspection to reveal the structure of the human mind.

the twins may have been raised in completely different environments.

rarely retransition to a cisgender identity.

show complete apathy and indifference to the first monkeys they encounter.”

are less likely to be strongly gender-typed.

any two biologically unrelated pairs are likely to share many striking

stress; least likely to benefit from

no sex difference in the brains of males and females.

has both biological and environmental influences.”