Paternal care by genetic fathers and stepfathers I: Reports from Albuquerque men

We present a biosocial model of human male parental care that allows male p arental allocations to be influenced not only by changes in the fitness (we lfare) of the recipient offspring, but also by their effects on the man's r elationship with the child's mother, The model recognizes four classes of r elationships between males and the children they parent: genetic offspring of current mates (combined relationship and parental effort), genetic offsp ring of previous mates (parental effort solely), step offspring of current mates (relationship effort solely), and stepchildren of previous mates (ess entially no expected investment). We test the model using data on parental investments collected from adult males living in Albuquerque, New Mexico, U .S.A. Four measures of paternal investment are examined: the probability th at a child attends college (2,191 offspring), the probability that a child who attends college receives money for it (N = 1,212), current financial ex penditures on children (N = 635), and the amount of time per week that men spend with children ages 5 to 12 years (N = 2,589), The tests are consisten t with a role for relationship effort in parental care: men invest more in the children of their current mates, even when coresidence with offspring i s not a confounder. (C) 1999 Elsevier Science Inc.