A renowned psychologist claims that motivated behaviors result from an effort to reduce tension caused by bodily needs such as hunger or thirst. Her philosophy most closely matches which theory?

Based on the Youth Risk Behavior Survey, which of the following is TRUE about reported cigarette use by 9th graders?

a) In 2005, cigarette use increased among White, non-Hispanic females. b) Ninth graders were less likely to smoke or report usage in 2005 than in 1991. c) In 1995, Black, non-Hispanic females were more likely to smoke than Hispanic females. d) The rate of cigarette use decreased from 9th to 12th grade in 1991.

What percentage of babies did Thomas and Chess find met their definition of "difficult" babies?

a. 10% b. 30% c. 50% d. 70%