Which psychologist developed a conditioning apparatus for animals and provided various practical applications of operant conditioning?

For the traits in which gender differences were reported in your text,

a. either all boys were higher than all girls on the trait or all girls were higher than all boys on the trait. b. average differences between boys and girls were quite large, but the differences at the extremes of the distributions were insignificant. c. there was substantial overlap between girls' and boys' abilities. d. the average score for boys was the same as the average score for girls.

Boys are more likely than girls to develop which of the following disorders?

a. anorexia nervosa c. bulimia nervosa b. hysteria d. elimination problems