A scientist interested in phenomena such as the natural variation in heart rate and hormones over the course of a day would be interested in

Grandma couldn't believe how much Andy had changed since she last saw him. He now had facial hair and his voice had deepened. Grandma is noticing Andy's

a. primary sex characteristics. c. adolescent growth spurt. b. secondary sex characteristics. d. pubertal shift.

Allen is running late for his social psychology class. He is hurrying across campus and is thinking about the instructor's reaction to his tardiness on an exam day

He passed by a small group of students clustered around someone who is lying on the ground, clutching his chest and gasping for breath. Allen did not stop to help because he simply was not aware of what was happening at the time. This failure to engage in prosocial behavior was probably due to Allen's ________. a) assumption that other bystanders would help b) not paying attention to the situation c) lack of training in emergency medical procedures d) desire to remain uninvolved with others' problems