In medicine, an important concern is the etiology of diseases. The same can be said about nonverbal behavior in the social sciences. The problem is that there is an inconsistency and lack of agreement in the discussion of nature versus nurture; genes versus environment etc. These either-or-all fallacies tend to ignore and neglect the reality that our social interactions and sociality are more complex and that it is not unilaterally determined. The purpose of this thesis is to shed light on the complexity of the matter at hand and to provide evidence for both sides of the argument.