Theoretical and empirical work suggests that social support is an important predictor of both psychological and physiological responses to stressors. A separate line of research shows that early life socioeconomic status programs physiological responses to stressors later in life. Bridging these two lines of research, I designed a series of studies to examine the ways in which the reception of social support can moderate physiological reactivity and emotional responses as a function of early life experience. In Study 1, I examined these questions in the context of an interpersonal interaction, while Study 2 utilized a social evaluative task. In Study 3, I used the same social evaluative task as in Study 2 and let social support vary freely by using two participants, and randomly assigning one to be the actor, and the other to be the evaluator. I found that early life socioeconomic status in interaction with the presence or absence of social support strongly predicted inflammatory responses (Study 1 and 2) and changes in oxytocin following an interpersonal interaction (Study 1). Finally, in Study 3, I found that perceptions of the evaluator's subjective social status and the speaker's subjective social status interacted to predict inflammatory responses. Together these studies show that the significance of social support as a predictor of changes in oxytocin and inflammation varies as a function of the nature of the stressor. In addition, these findings show that with regards to social evaluative threat, the actor's perception of their evaluator's social class matters more than their objective social class or that of their evaluator.