Finally, data collected by Harris, Heard & King (2000) from a subsample of Add Health participants (n=13,308), described above, indicate that the makeup of the family may affect the parent-child relationship. The presence of siblings under the age of six, for example, appears to have a negative affect on father-child closeness, though it does not affect the pair's participation in joint activities. Residing with an adult relative, such as a grandparent, appears to have a negative affect on the quantity of time fathers spend with their children.