The debate between whether nature is the cause of human behaviors, or nurture, is ongoing, and there have been many studies in the recent past that have tried to conceive a conclusion. Most of these studies have indicated that it is not one or the other that makes humans do what they do, but it is, to an extent, a combination of both.
Of course, some situations call for one rather than the other, but if the discussion is revolving around the topic of behaviors, I believe that the root motivator for what we do, is for the most part, nurture, rather than nature. To clarify, my opinion of what nurture is, is that it is anything around us, in our environment, that has affected the way we behave. For example, it is arguable that our gender genes (Y/X chromosomes) are the reason why females may pick something that resembles more care-taking (e.i. the monkey experiment when the female monkeys chose the fluffy dolls), but I think that rather than our genes being the motivator, it is that our mothers have acted a certain way to raise us, with care and love, that makes females more attracted to something that requires responsibility and care-giving. It is shown, in the Cambridge Experiment, that a parent naturally prefers their daughter to be choose more mild toys that require less intense action, which already points the child into the direction of making that choice in their future. (Vise Versa for a boy).