Psychologist Karen Horney in her article "The Problem of the Monogamous Ideal", indicates that the overestimation of love leads to disillusionment; the desire to possess the partner results in the partner wanting to escape; and the friction against sex result in non-fulfillment. Disillusionment plus the desire to escape plus non-fulfillment result in a secret hostility, which causes the other partner to feel alienated. Secret hostility in one and secret alienation in the other cause the partners to secretly hate each other. This secret hate often leads one or the other or both to seek love objects outside the marriage or relationship.