Which of the following neurotransmitters has been implicated in the development of migraine headaches?

Chimps and pigeons trying to get bananas were examples of __________ occurring in

nonhuman animals. Fill in the blanks with correct word

Harlow's research with infant monkeys who were reared with surrogates suggests that

a. infant monkeys do not derive comfort from nonnutritive sucking. b. softness and warmth are inherently more reinforcing than the mother's characteristic body scent. c. physical contact with cuddly objects is a biological need. d. deprivation of contact with the mother is more serious than deprivation of contact with peers. e. research with nonhuman primates is difficult to generalize to human infants.