The feelings associated with romantic love function to ensure the greater reproductive fitness of individuals. The obligations of individuals in romantic relationships to preserve these bonds are based in kin selection theory, where by exhibiting aggressive behavior, a mate can use intimidation and dominance to ward off other potential predators, thus protecting the pair bond and their actual or potential offspring. This has however evolved to the point where it has become detrimental to the fitness of individuals; what is causing attachment to occur in a relationship, is now causing one partner to harm the other.