Julio belongs to a youth group, a book club, and the school debate team. He compares himself to these groups, and finds his values confirmed. According to the text, what are these groups called?

A boy is teaching his younger sister how to make her bed. At first, he tells her she did a good job if she gets the bedspread pulled up, even if the sheets are still rumpled. Each following day,

he encourages her to be a little neater before telling her she did a good job. The boy may not know it, but he is using a. secondary reinforcement. b. primary reinforcement. c. a fixed-interval schedule. d. shaping by successive approximations.

A brief period of fertility that corresponds to the time of ovulation and is associated strongly with an animal's sexual receptivity is known as

A) menstruation. B) the organizing effect. C) estradiol. D) estrus.