Prosocial behavior intends to help others.
Defensive behavior intends to protect oneself from the aggressive behaviors of others.
In a study of children in day care centers, a researcher found that very young children took objects from others, hit others, interfered with others' activities, or made commands in about half of their interactions with other children. Most conflicts were over possession of a toy. These toddler struggles appeared to be truly social in nature . Rather than treating the other child as a physical obstacle to toy possession, these youngsters showed evidence that they recognized the human qualities of their adversaries. They used language and appropriate gestures, and would often wrangle over a toy even when a duplicate of that toy was available to them.