Similar but less physically coercive approaches may involve holding the child and psychologically encouraging the child to vent anger toward her or his biological parent.
Such a distinction is useful when the individual who is considered the legal parent of the child is not the individual who is believed to be the child's biological parent.
Any person (other than the biological parent of a child) who marries the parent of that child becomes the stepparent of the child, either the stepmother or stepfather.
As such, in a species that requires two parents to reproduce, an organism is most likely to show altruistic behavior to a biological parent, full sibling, or direct offspring.