According to research conducted by Olds and Milner (1954), rats who had the ________ of their brains stimulated experienced intense sensations of pleasure

Which of the following statements about sex differences in spatial abilities is true?

A) Experience contributes to females' superior spatial performance. B) Sex differences in spatial abilities emerge as early as the first few months of life. C) One explanation is that heredity enhances left-hemispheric functioning. D) Girls spend far more time than boys in play involving manipulative activities.

A percentile is _____

a. the percentage of scores in a distribution equal to or greater than a particular score b. a score at or above which a specified percentage of the scores in a distribution fall c. a score at or below which a specified percentage of the scores in a distribution fall d. always the midpoint of a class interval