Rovee-Collier and colleagues have created a paradigm in which infants are trained to kick a

Research demonstrating hypothalamus differences between homosexual and heterosexual men was compromised by which of the following flaws?

a) All of the homosexual men died of AIDS, and the illness may have caused the hypothalamus changes. b) None of the heterosexual men reported on whether they had ever had intellectual disabilities. c) The heterosexual men were drawn from a population of graduate students, while the homosexual men were drawn from a general community population. d) Many of the heterosexual men in the sample were later found to have been dishonest about their sexual orientation.

According to Freud, the energy generated by the sexual instinct is known as the ______

a. secondary process c. libido b. pleasure principle d. fixated process