All marriages have their ups and downs, but the semihappy marriage is chronically ambivalent. It's a marriage that's neither miserable nor all that successful. Semihappy spouses genuinely can't decide if they should stick it out and live with the faults in the marriage, or if those faults are too much to handle. Many semihappy marriages are high-functioning — almost like business partnerships or friendships — but they lack important elements. In other cases, spouses wonder if their expectations are too high and worry that they're being selfish, but they also can't shake the feeling that they might be in the wrong marriage. Researchers estimate that anywhere from 55% to 65% of divorces hail from this group of low-conflict yet listless marriages.