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.”

in both males and females; only in females

only in males; only in females