And that can have costs in a relationship

The answers confirmed her initial suspicions. It was fairly common for the students to be turned off by the very thing that first attracted them to the person they were-or had been-dating. In the past few decades Felmlee has been conducting studies with couples to explore this problem of what she calls “fatal attractions.” “We asked one guy what he liked about a former girlfriend, and he listed every part of this woman’s body, including the most intimate parts. And when he answered the question ‘Why did you split up?’ he said that the relationship was based only on lust. I thought, ‘Well, he got what he wanted initially.’”

Felmlee says that someone who is seen as humorous at the start of a relationship can later be considered “flaky” or “immature

The list goes on. ” One woman reported that she was attracted by her boyfriend’s sense of humor, but then she complained that he “doesn’t always take other people’s feelings seriously (jokes around too much).”

Caring is another positive quality with a downside. Felmlee reports that one woman was attracted to a man who was “very attentive” and persistent, but she disliked that he “tries to be controlling.” Another woman described a former partner as “caring,” “sensitive” and someone who listened to her. Yet she did not like the fact that he also got jealous very easily, and “he hated it when [she] wanted to spend time with other friends.”

In a way, fatal attraction resembles the inverse of a concept called hedonic reversal, which is when something that is intrinsically unpleasant-like eating hot chili peppers-becomes enjoyable with repeated exposure. We start off finding a quality of our mates attractive, and over time it becomes annoying. Felmlee has tested people all over the world, and the same pattern seems to hold.

The other thing she consistently finds is that the more strongly someone exhibits a particular trait, the more likely that trait is to become aggravating. Again, the dose matters. So, for example, a spouse will sooner become annoyed with a partner who is exceptionally funny and endlessly telling jokes than with one who makes a witty remark on occasion.

What’s going on here? Why do strengths become weaknesses and endearing qualities irritants? “I call it disillusionment,” Felmlee says. She believes the answer may be related to something called social exchange theory. “Extreme traits have rewards,” she says, “but they also have costs associated with them, especially when you are in a relationship.”

Take independence. “Independence can be valued in a partner, one who can stand on his own two feet,” Felmlee says. “But if you’re too independent, that means you don’t need your wife. ”

Felmlee has thought a lot about how couples might get around some of these points. Self-awareness helps. She recalls one man who complained that his wife was stubborn. “On the other hand, what he really liked about her and loved from the beginning was her strength of character. And he said he was entirely committed to her and planned to be with her for the rest of his life.” This man, at least, seemed to be aware that positive qualities have an inherent downside. “And he seemed aware of his own limitations. He said, ‘I’m stubborn, too, and she has to put up with that.’”

There wasn’t enough love

“It’s not like you get this perfect person, and there are no downsides to his or her qualities,” Felmlee says. “It just doesn’t happen.”

Social AllergensEven if your partner only occasionally leaves a clump of hair in the drain or talks while he is eating, spending a lifetime with someone creates ample opportunities for repeated exposure. “The same thing keeps happening over and over and over again in a marriage,” says Elaine Hatfield, a psychologist at the University of Hawaii at Manoa, “because we all have our goofy little quirks.” Hatfield says that these annoyances get amplified according to the principles of something called equity theory.