Halter, Colt; Jacobsen, Natalia; Wood, Elizabeth; Capitanio, John; Higley, James (Brigham Young University)
Faculty Advisor: Higley, James (Brigham Young University, Psychology)
Studies show that early parent-infant attachment categorization is not only predictive of child outcomes, but also second-generation parenting behavior. Few studies, however, have longitudinally assessed how infant behavior inhibition affects future adult parenting styles. Studies show that behavior inhibition is interindividually stable across time and situation, with elevated plasma cortisol levels serving as a marker of anxious temperament. In this study, we investigate the relationship between infant cortisol concentrations and later parenting behavior. We hypothesized that high cortisol levels in infancy would predict deficits in maternal behaviors later in adulthood. Due to their biological and behavioral similarities to humans, rhesus macaques (Macaca mulatta) were used. The subjects were 123 females, first studied when they were 3-4 months of age, underwent a 25-hour mother-infant separation, during which four blood samples were obtained: one at 2-hours, 7-hours, 11.5-hours, and 12-hours post-separation. 3-5 years later, these same subjects were observed as mothers, and four 300-second observations of maternal behaviors that are traditionally associated with the quality of the mother-infant attachment relationship were obtained—infant approaches and leaves, and mutual-ventral contact. Other behavioral measures that characterize rhesus monkey anxiety, including self-directed behaviors, were also recorded. Controlling for infant age and sex, results showed that infant cortisol predicted adult maternal deficits, with high cortisol concentrations predicting high rates of infant approaches and leaves (p<.03) and low rates of mutual ventral contact (p<.03). High cortisol concentrations also predicted mothers' anxiety-like self-directed behaviors (p=.04). These results suggest that females with high cortisol as infants show anxiety-like behaviors as adults and exhibit deficient parenting behaviors, leading their infants to drive the mother-infant relationship. To the extent that these results generalize to humans, this study lends empirical evidence to the proposed relationship between early life anxiety and deficits in later parenting behaviors.