Work hours affect spouse's cortisol secretion--for better and for worse.

OBJECTIVE In a sample of 52 German dual-earner couples with at least one child under age 5, we examined the bodily costs and benefits of the amount of time each spouse spent on productive activities. METHODS Diary reports of time allocated to formal and informal work activities were analyzed according to the Actor-Partner Interdependence model. RESULTS Hierarchical linear models showed that each hour an individual allocated to market, as well as household work, increased his or her total cortisol concentration (by 192 and 134 nmol/l, respectively). Unexpectedly, the time the spouse allocated to paid work also raised an individual's total cortisol concentration (by 64 nmol/l). In line with our expectations, there was a tendency for the time the spouse allocated to household work to decrease the individual's cortisol concentration (by 81 nmol/l). CONCLUSIONS This study contributes to the body of evidence on the complex nature of social relationships and complements the literature on specific working conditions and couples' well-being.