Interpersonal behavior has been observed in a number of studies, and yet the two relational issues of control and affiliation are commonly reflected in all of them. Relational control includes such behaviors as dominance, assertiveness, retiring, and following, while relational affiliation includes involvement, acceptance, friendliness, and affection and association, and their opposites of aloofness, rejection, unfriendliness, hate, and disassociation. Although both control and affiliation are considered major organizing principles of social behavior, only relational control has been extensively investigated by researchers to date. In order to encourage research in relational affiliation, a conceptualization of affiliation that is consistent with the relational approach is needed. Conceiving of affiliation as the horizontal dimension of relationships, messages may be viewed as representing one of three types of affiliative moves: (1) an attempt to approach the person and define the relationship as closer, more involving, more friendly, and more loving; (2) an attempt to retract from the person and define the relationship as more distant, less involving, and less friendly; and (3) an attempt to remain stationary and not change the closeness or distance of the relationship. A scheme for coding affiliation from verbal interaction can then be used. (A set of 12 research propositions about relational affiliation drawn from recent communication theory and research are discussed.) (EL)