The entire family participates in the success of the home dialysis patient. Isolation and study of discrete quantifiable aspects of behavior within the family may allow identification of patients with a greater risk of failure, thus making it possible to help such patients succeed. A single such factor, ‘intrafamily identity’, measured in each of 40 diverse families before one family member began a home dialysis program, was found to correlate with success in the program 1 year later. This finding also may contribute to an understanding of systematic patterns of behavior within all families, with special emphasis upon the ability of family members to cope with continuing stress.