| Description |
We conducted exploratory signal detection analyses in an ethnically diverse sample of 338 kindergarten children (4-6 years old) to examine the evolutionary-developmental theory of biological sensitivity to context. The theory proposes that there is a curvilinear, U-shaped relation between early exposure to adversity, support and the magnitude of physiological responses to stress, with high reactivity phenotypes emerging under both highly stressful and highly protective early environmental conditions. Across both sympathetic and adrenocortical systems, we found evidence for high reactivity profiles. Higher cortisol reactivity was shown by children whose parents reported greater use of restrictive and controlling parenting practices. Likewise, the combination of high family stress and unstable family economic conditions uniquely predicted greater activation of the sympathetic system to laboratory stressors. In addition, a relatively high proportion of children from very low stressful family environments showed high sympathetic and adrenocortical reactivity phenotypes. No indices of contextual and familial stressors were identified by signal detection analysis that were closely (either singly or in combination) associated with high parasympathetic reactivity. The exploratory findings offered confirmatory support for the hypothesized U-shaped relation between childhood stress, support and stress responsivity, with children from moderately stressful family environments showing the lowest reactivity levels. |
