What is an unconditioned behavior?

An unconditioned behavior is one that has not been reinforced, positively or negatively, by an outside source. For instance, an unconditioned behavior is one that occurs because it exists naturally, i.e a baby crying because it is hungry. It will not continue as a true behavior if it is not reinforced. Reinforcement can occur either negatively (you get hurt for doing it, for instance) or positively (something that feels good). Either way, an unconditioned behavior will only continue (and becomes a conditioned behavior) if it creates some kind of response. Here's an example: A child cries because s/he fell and skinned his/her knee. The parent ignores the cries of the child. The other parent oohs and aahs over the kid. Over time, if the cries get no response, the child will not cry when s/he falls and skins his/her knees. If there is a response from the parent, the child will continue to cry about minor injuries.