What percent of American adolescents have lost their virginity by their senior year of high school?

Sarah, a graduate student in psychology, just heard about a five-year-old child who has already learned calculus

She is thinking about doing an in-depth study of the child for her dissertation because such early-life math skill is so rare. Sarah is considering which research method? A) Naturalistic observation B) Experiment C) Independent study D) Case study

Susan trained her rat to press a bar in a Skinner box in order to get a food pellet. Susan's rat pressed the bar a lot. However, later when Susan ran out of food pellets her rat eventually stopped pressing the bar. What had happened?

a) conditioned aversion b) satiation c) extinction d) withdrawal