Blunted cardiovascular responses to stress have been associated with both mental and physical health concerns. This multi-method, longitudinal study examined the role of chronic social-developmental stress from adolescence onward as a precursor to these blunted stress responses. Using a diverse community sample of 184 adolescents followed from age 13 to 29 along with friends and romantic partners, this study found that high levels of parental psychological control at age 13 directly predicted a blunted heart rate response and indirectly predicted blunted respiratory sinus arrhythmia (RSA) reactivity under stress. Heart rate effects were mediated via indicators of a developing passive response style, including observational measures of withdrawal during conflict with friends and romantic partners, social disengagement, and coping with stressors by using denial. RSA effects were mediated via withdrawal during conflict with romantic partners and coping by using denial. The current findings are interpreted as suggesting a mechanism by which a key social/developmental stressor in adolescence may alter relational and ultimately physiological patterns of stress responding into adulthood.