The aim of this study was to examines the effects of life-span contextual variation on father-child relationships. Sixty families in which both parents were either younger than 26 or older than 29 when they began childbearing, and whose oldest or only child was between the ages of 3 and 5 at the time of the study participated. Questionnaires were administered to fathers, assessing their conceptualizations of child development, identification with social and parental roles, time spent with children, marital satisfaction, and job satisfaction, work-home compatibility, and social network attributes. Videotaped observations of father-child play were also collected. Older fathers established stronger connections to extra-familial contexts, displayed more complex conceptualizations of child development, and relied more upon verbal mechanisms to engage children during play than younger fathers. Younger fathers were more strongly tied to kin, maintained a more traditional style of fathering, and engaged their children through physical stimulation more than older fathers. Older fathers' more perspectivistic, verbal style is likely to be more cognitively stimulating, and may stimulate faster cognitive advances and subsequent academic success in their children. The children of younger men, on the other hand, should benefit from heightened affective arousal of their style of play. Contains 67 references. (Author/MDM)