One critique of Freud's theory of the Oedipus complex is that it cannot truly be tested. This critique holds that it is impossible to prove that conflicts between children and their parents (particularly their fathers) are caused by an underlying Oedipal urge.
To this way of thinking, the idea of the Oedipus complex is too simplistic. There are many other things, the critique goes, that could cause children and their parents to come into conflict with one another. Because there are so many possible causes of conflict, and because it is impossible to prove what the source of conflict is, the theory of the Oedipus complex is inherently unprovable.