It was predicted that the amount of satisfaction following an interpersonal exchange will be higher when the resource given is similar to the one reciprocated and lower when they are dissimilar. Interpersonal exchange situations were experimentally created in which two independent variables were manipulated. (Author)

Mexican-American, Negro, and Anglo-American children participating in a two-person, two-choice game, showed that similar female ethnic pairs cooperated significantly more than dissimilar pairs; that females in the three groups differed significantly in the amount of cooperative behavior, and that reinforcement did not affect cooperative behavior.…

It was concluded that both social and vocal elements are necessary to stimulate a general increase in the number and length of consonant utterances, but there was no evidence that stimulation encouraged infants to imitate the consonant phonemes presented. (Author)

Systematic methods are needed for studying group development over time. The method described here permits interpretive description of a group session, useful both for feedback to the group and for further study of group processes. (Author)