It's so obvious and I may have stated it before, but the theory of memetic rewards(1) and memetic closure clearly predict the Freudian observation that we tend to marry our fathers and mothers.
As the professor in Woody Allen's film Crimes and Misdemeanors points out, we want to escape the wrongs our parents have done us, but we also expect the spouse to act as the surrogate of the parent so that we may re-fight and finally win the battles that we lost as children.
This is exactly what the principle of memetic closure tells us, and it also predicts intergenerational cycles of abuse, and even patterns of genocide at a national level.
Basically, we don't get the "reward" until we have closed the circle, the circuit, i.e., we have "learned" the whole action. We have either succeeded in imitating the other, or in being imitated by them, i.e., achieved memetic closure. Our in-built trafficking in memes becomes destructive when we get stuck in these compulsive cycles of abuse.
How to break them? Whatever therapy must needs be build upon this theory.
(1) "Memetic orgasm"