The basis of a healthy social contract between individuals is reciprocity. At root, individuals bond–as family members, friends, lovers–because they give each other pleasure. The more pleasure–and the more equal the sharing–the closer the bond.
The game starts at birth. Adults must start it, as they are the more competent partner (or should be.) Given the average infant, the average advice on child-rearing results in a baby who soon realizes that people make him feel safe and comfortable and happy. Within weeks, the baby is responding to this with signs of happiness as well as notices of “something’s wrong, fix it!” Caring adults are then rewarded by the baby’s joy. They like the smiles, the coos, the wiggly arms and legs, all the signals that the baby is happy and likes having them around.
Adults then intensify their attempts to get these happy reactions from the baby, repeating the ones that work–because they’re enjoying the baby just as the baby is enjoying them. Before the average baby is a year old, he knows that adults take pleasure in him–some of the time–and can tell when he’s pleased an adult. Average babies begin consciously seeking to please their adults at least some of the time–more if the adults are also playing fair, not demanding more than the baby can give. (Adults have longer attention spans, and often want babies to interact longer than the baby can.)
This is the basis of healthy social motivation.