I was thinking that there had to be a flaw in the study because my intuition tells me that the opposite of what they found is true. Altruistic people would hav

I was thinking that there had to be a flaw in the study because my intuition tells me that the opposite of what they found is true. Altruistic people would have more difficulty breaking up with their sexual partners (they care more about the other person); so I would assume that they would be more willing to compromise and, therefore, their relationships would last longer (and thereby they would have fewer of them). You could argue that altruistic people get dumped more often but that would go against basic evolutionary principles.