Which of the following concepts explains why preoperational children can seem exasperatingly selfish or uncooperative at times?

Cultural variations in the emergence of basic skills such as sitting and walking demonstrate that environmental factors

a. do not affect early motor development. b. can accelerate or slow early motor development. c. can accelerate early motor development. d. can slow early motor development.

Sandy missed class because she is sick, but Luis did attend the lecture. Sandy asks Luis if she can borrow his notes. If Luis considers Sandy's situation from her point of view and decides to offer help without expecting some form of payback, he is most likely

a. invoking the norm of reciprocal altruism. b. operating under an altruistic motive. c. operating under an egoistic motive. d. following the negative state relief model.