Twin studies indicate that
A) there is a genetic basis for homosexuality in males as well as in females.
B) early family environment is more important than genes for the development of homosexuality.
C) a male child whose older twin sisters are heterosexual is more likely to be homosexual.
D) homosexual women are likely to have homosexual male relatives.
E) identical male twins are less likely to be concordant for homosexuality than are fraternal male twins.

Question

Quizplus · Accepted Answer

Twin studies have consistently shown a higher concordance rate for homosexuality in identical twins compared to fraternal twins, indicating a genetic basis for homosexuality. This applies to both males and females. Studies have also shown that genetic factors account for approximately 30-40% of the variation in sexual orientation.

Twin Studies Indicate That