Daily interactions in the parent-adult child tie: Links between children's problems and parents' diurnal cortisol rhythms.

•We conducted a daily diary study in which middle aged respondents reported their daily social interactions with their adult children and provided saliva which was assayed for cortisol.•We examined whether daily social interactions (negative and positive) with children who suffer problems (e.g., health problems, trouble with the law, financial trouble) were associated with parents’ diurnal cortisol rhythms.•Parents have more negative interactions with children who suffer problems but no fewer positive interactions with those children.•Negative interactions were associated with cortisol but differentially for interactions with children who suffer health vs. lifestyle problems (e.g. trouble with the law).•Interactions with children who suffer lifestyle problems appear to have more lingering effects on parents’ cortisol responses.