Parotid salivary secretion was regarded as a correlate of 80 men and women's stress arousal: lesser amounts of secretion accompany higher levels of arousal. Experimental results obtained in two-person interpersonal bargaining situations were then interpreted in terms of this formulation. Bargainers who had unequal advantages (as in a unilateral threat situation) or disproportionately greater potential payoff had relatively little parotid salivary secretion compared to their partners who interacted under disadvantages or had no promise of extra reward. Three variations of the trucking game were employed. Salivary parotid responses were similar for bargainers and failed to discriminate conditions of no threat and bilateral threat. Subjects under unilateral threat differed, however, and seemed to display specific stress characteristics.