One partner is more in love than the other. And more love the loving partner wants from the other, the less the other partner feels like giving. … the more-in-love partner was in what I term the “one-down position,” while the less-in-love partner was in the “one-up position.”

One-downs try harder. Feeling insecure and wanting to regain a sense of control, they labor to enhance their “attraction power”: wearing most flattering clothes, spending hours at the mirror, thinking up clever things to say, honing culinary skills, spending money freely on gifts, restaurant meals, and romantic diversions – in sum, making yourself as desirable as possible. … If you prove too appealing to the one you want – to the point where he’s clearly more in love with you than you with him – your relationship will fall out of balance. You’ve become the one-up. Or, if you’re frightened by your partner’s distance, you become the one-down. And herein was the missing link I sought:

The very urge to attract someone, to bring another person under your emotional control, contains the potential for upsetting the balance of the relationship. And that is because the feeling of being in love is biochemically linked to the feeling of being out of control. Once you feel completely in control or sure of another person’s love, your feelings of passion begin to fade. Gone is the challenge, the emotional spark, the excitement.

Of course, we all know that the dizzy, delicious feelings of new love can’t last forever. In a balanced relationship, after the initial passion fades, the partners move into a phase of enduring intimacy and warmth. But when one partner falls more deeply in love than the other, it can trigger harmful patterns between them.