Associations between parents’ marital functioning, maternal parenting quality, maternal emotion and child cortisol levels

between marital functioning and a wide range of child adjustment problems (Buehler et al., 1997; Emery, 1982, 1989, 1999; Grych & Fincham, 1990, 2001); however, the pathways that give rise to these associations are not clear. Several marital discord theories, including the cognitive-contextual model (Grych, 1998; Grych & Fincham, 1990, 1993; Grych, Fincham, Jouriles, & McDonald, 2000; Grych, Harold, & Miles, 2003), the emotional security hypothesis (Davies & Cummings, 1994, 1998; Davies, Harold, Goeke-Morey, & Cummings, 2002) and the specific emotions model (Crockenberg & Forgays, 1994, 1996; Crockenberg & Langrock, 2001a, 2001b) suggest that poor marital functioning constitutes a stressor leading to children’s emotional arousal. Although there has been considerable interest of late in integrating physiological measures into studies examining associations between parent’s marital functioning and child outcomes (Ballard, Cummings, & Larkin, 1993; El-Sheikh, 1994; El-Sheikh, Ballard & Cummings, 1994; El-Sheikh, Cummings, & Goetsch, 1989; Gottman & Katz, 1989; Gottman & Levinson, 1992; Katz & Gottman, 1995, 1995b; Repetti, Taylor, & Seeman, 2002), surprisingly, there are no published studies with children examining how parent marital quality is related to the activity of one of the body’s main physiological systems for responding to stressors, the hypothalamic-pituitary-adrenal axis (HPA axis), and its major endproduct, cortisol. HPA axis activity, as measured by levels of salivary cortisol, is of interest in relation to marital functioning for several reasons. First, cortisol levels are extremely sensitive to social stressors and supports, particularly those emerging from close interpersonal relationships (Adam, Klimes-Dougan, & Gunnar, in press; Gunnar & Donzella, 2002; Repetti et al., 2002;). Second, cortisol levels have effects on many physiological and behavioral processes. When secreted transiently cortisol aids survival by mobilizing energy, increasing cardiovascular tone, focusing attention and redirecting immune resources, while suppressing growth, reproduction, digestion and tissue repair processes that are less important for immediate survival (Johnson, Kamilaris, Chrousos, & Gold, 1992). However, excessive amounts of cortisol can disrupt learning and memory, affect synaptic plasticity and have deleterious physical consequences such as risks of insulin-resistant diabetes mellitus and chronic immune suppression, and as such, has potential implications for children’s immediate functioning as well as their long-term physical, cognitive and emotional development (Repetti, Seeman, & Taylor, 2002; Scerbo & Kolko, 1994; Smider et al., 2002). Third, although there has been less human research on the topic, animal models suggest that frequent or chronic elevation of cortisol levels impairs International Journal of Behavioral Development 2007, 31 (3), 218–231