The trouble is that for most of the five years they've been together, Greg and Emily have been having one version or another of the same fight. Greg, a music promoter with a large circle of friends, wants to host dinner parties every Friday-casual, animated get-togethers with heaping bowls of pasta and flowing bottles of wine. He's been giving Friday-night dinners since he was a senior in college, and they've become a highlight of his week and a treasured piece of his ident.i.ty.

Emily has come to dread these weekly events. A hardworking staff attorney for an art museum and a very private person, the last thing she wants to do when she gets home from work is entertain. Her idea of a perfect start to the weekend is a quiet evening at the movies, just her and Greg.

It seems an irreconcilable difference: Greg wants fifty-two dinner parties a year, Emily wants zero.

Greg says that Emily should make more of an effort. He accuses her of being antisocial. "I am social," she says. "I love you, I love my family, I love my close friends. I just don't love dinner parties. People don't really relate at those parties-they just socialize. You're lucky because I devote all my energy to you. You spread yours around to everyone."

But Emily soon backs off, partly because she hates fighting, but also because she doubts herself. Maybe I am antisocial, she thinks. Maybe there is something wrong with me. Whenever she and Greg argue about this, she's flooded with childhood memories: how school was tougher for her than for her emotionally hardier younger sister; how she seemed to worry more than other people did about social issues, like how to say no when someone asked her to get together after school and she preferred to stay home. Emily had plenty of friends-she's always had a talent for friendship-but she never traveled in packs.

Emily has suggested a compromise: What if Greg gives his dinner parties whenever she's out of town visiting her sister? But Greg doesn't want to host dinners by himself. He loves Emily and wants to be with her, and so does everyone else, once they get to know her. So why does Emily withdraw?

This question, for Greg, is more than mere pique. Being alone for him is a kind of Kryptonite; it makes him feel weak. He had looked forward to a married life of shared adventures. He'd imagined being part of a couple at the center of things. And he'd never admitted it to himself, but for him being married meant never having to be by himself. But now Emily is saying that he should socialize without her. He feels as if she's backing out of a fundamental part of their marriage contract. And he believes that something is indeed wrong with his wife.

Is something wrong with me? It's not surprising that Emily asks herself this question, or that Greg aims this charge at her. Probably the most common-and damaging-misunderstanding about personality type is that introverts are antisocial and extroverts are pro-social. But as we've seen, neither formulation is correct; introverts and extroverts are differently social. What psychologists call "the need for intimacy" is present in introverts and extroverts alike. In fact, people who value intimacy highly don't tend to be, as the noted psychologist David Buss puts it, "the loud, outgoing, life-of-the-party extrovert." They are more likely to be someone with a select group of close friends, who prefers "sincere and meaningful conversations over wild parties." They are more likely to be someone like Emily.

Conversely, extroverts do not necessarily seek closeness from their socializing. "Extroverts seem to need people as a forum to fill needs for social impact, just as a general needs soldiers to fill his or her need to lead," the psychologist William Graziano told me. "When extroverts show up at a party, everyone knows they are present."

Your degree of extroversion seems to influence how many friends you have, in other words, but not how good a friend you are. In a study of 132 college students at Humboldt University in Berlin, the psychologists Jens Aspendorf and Susanne Wilpers set out to understand the effect of different personality traits on students' relationships with their peers and families. They focused on the so-called Big Five traits: Introversion-Extroversion; Agreeableness; Openness to Experience; Conscientiousness; and Emotional Stability. (Many personality psychologists believe that human personality can be boiled down to these five characteristics.)

Aspendorf and Wilpers predicted that the extroverted students would have an easier time striking up new friendships than the introverts, and this was indeed the case. But if the introverts were truly antisocial and extroverts pro-social, then you'd suppose that the students with the most harmonious relationships would also be highest in extroversion. And this was not the case at all. Instead, the students whose relationships were freest of conflict had high scores for agreeableness. Agreeable people are warm, supportive, and loving; personality psychologists have found that if you sit them down in front of a computer screen of words, they focus longer than others do on words like caring, console, and help, and a shorter time on words like abduct, a.s.sault, and hara.s.s. Introverts and extroverts are equally likely to be agreeable; there is no correlation between extroversion and agreeableness. This explains why some extroverts love the stimulation of socializing but don't get along particularly well with those closest to them.

It also helps explain why some introverts-like Emily, whose talent for friendship suggests that she's a highly agreeable type herself-lavish attention on their family and close friends but dislike small talk. So when Greg labels Emily "antisocial," he's off base. Emily nurtures her marriage in just the way that you'd expect an agreeable introvert to do, making Greg the center of her social universe.

Except when she doesn't. Emily has a demanding job, and sometimes when she gets home at night she has little energy left. She's always happy to see Greg, but sometimes she'd rather sit next to him reading than go out for dinner or make animated conversation. Simply to be in his company is enough. For Emily, this is perfectly natural, but Greg feels hurt that she makes an effort for her colleagues and not for him.

This was a painfully common dynamic in the introvert-extrovert couples I interviewed: the introverts desperately craving downtime and understanding from their partners, the extroverts longing for company, and resentful that others seemed to benefit from their partners' "best" selves.

It can be hard for extroverts to understand how badly introverts need to recharge at the end of a busy day. We all empathize with a sleep-deprived mate who comes home from work too tired to talk, but it's harder to grasp that social overstimulation can be just as exhausting.

It's also hard for introverts to understand just how hurtful their silence can be. I interviewed a woman named Sarah, a bubbly and dynamic high school English teacher married to Bob, an introverted law school dean who spends his days fund-raising, then collapses when he gets home. Sarah cried tears of frustration and loneliness as she told me about her marriage.

"When he's on the job, he's amazingly engaging," she said. "Everyone tells me that he's so funny and I'm so lucky to be married to him. And I want to throttle them. Every night, as soon as we're done eating, he jumps up and cleans the kitchen. Then he wants to read the paper alone and work on his photography by himself. At around nine, he comes into the bedroom and wants to watch TV and be with me. But he's not really with me even then. He wants me to lay my head on his shoulder while we stare at the TV. It's a grownup version of parallel play." Sarah is trying to convince Bob to make a career change. "I think we'd have a great life if he had a job where he could sit at the computer all day, but he's consistently fund-raising," she says.

In couples where the man is introverted and the woman extroverted, as with Sarah and Bob, we often mistake personality conflicts for gender difference, then trot out the conventional wisdom that "Mars" needs to retreat to his cave while "Venus" prefers to interact. But whatever the reason for these differences in social needs-whether gender or temperament-what's important is that it's possible to work through them. In The Audacity of Hope, for example, President Obama confides that early in his marriage to Mich.e.l.le, he was working on his first book and "would often spend the evening holed up in my office in the back of our railroad apartment; what I considered normal often left Mich.e.l.le feeling lonely." He attributes his own style to the demands of writing and to having been raised mostly as an only child, and then says that he and Mich.e.l.le have learned over the years to meet each other's needs, and to see them as legitimate.

It can also be hard for introverts and extroverts to understand each other's ways of resolving differences. One of my clients was an immaculately dressed lawyer named Celia. Celia wanted a divorce, but dreaded letting her husband know. She had good reasons for her decision but antic.i.p.ated that he would beg her to stay and that she would crumple with guilt. Above all, Celia wanted to deliver her news compa.s.sionately.

We decided to role-play their discussion, with me acting as her husband.

"I want to end this marriage," said Celia. "I mean it this time."

"I've been doing everything I can to hold things together," I pleaded. "How can you do this to me?"

Celia thought for a minute.

"I've spent a lot of time thinking this through, and I believe this is the right decision," she replied in a wooden voice.

"What can I do to change your mind?" I asked.

"Nothing," said Celia flatly.

Feeling for a minute what her husband would feel, I was dumbstruck. She was so rote, so dispa.s.sionate. She was about to divorce me-me, her husband of eleven years! Didn't she care?

I asked Celia to try again, this time with emotion in her voice.

"I can't," she said. "I can't do it."

But she did. "I want to end this marriage," she repeated, her voice choked with sadness. She began to weep uncontrollably.

Celia's problem was not lack of feeling. It was how to show her emotions without losing control. Reaching for a tissue, she quickly gathered herself, and went back into crisp, dispa.s.sionate lawyer mode. These were the two gears to which she had ready access-overwhelming feelings or detached self-possession.

I tell you Celia's story because in many ways she's a lot like Emily and many introverts I've interviewed. Emily is talking to Greg about dinner parties, not divorce, but her communication style echoes Celia's. When she and Greg disagree, her voice gets quiet and flat, her manner slightly distant. What she's trying to do is minimize aggression-Emily is uncomfortable with anger-but she appears to be receding emotionally. Meanwhile, Greg does just the opposite, raising his voice and sounding belligerent as he gets ever more engaged in working out their problem. The more Emily seems to withdraw, the more alone, then hurt, then enraged Greg becomes; the angrier he gets, the more hurt and distaste Emily feels, and the deeper she retreats. Pretty soon they're locked in a destructive cycle from which they can't escape, partly because both spouses believe they're arguing in an appropriate manner.

This dynamic shouldn't surprise anyone familiar with the relationship between personality and conflict resolution style. Just as men and women often have different ways of resolving conflict, so do introverts and extroverts; studies suggest that the former tend to be conflict-avoiders, while the latter are "confrontive copers," at ease with an up-front, even argumentative style of disagreement.

These are diametrically opposite approaches, so they're bound to create friction. If Emily didn't mind conflict so much, she might not react so strongly to Greg's head-on approach; if Greg were milder-mannered, he might appreciate Emily's attempt to keep a lid on things. When people have compatible styles of conflict, a disagreement can be an occasion for each partner to affirm the other's point of view. But Greg and Emily seem to understand each other a little less each time they argue in a way that the other disapproves of.

Do they also like each other a little less, at least for the duration of the fight? An illuminating study by the psychologist William Graziano suggests that the answer to this question might be yes. Graziano divided a group of sixty-one male students into teams to play a simulated football game. Half the partic.i.p.ants were a.s.signed to a cooperative game, in which they were told, "Football is useful to us because to be successful in football, team members have to work well together." The other half were a.s.signed to a game emphasizing compet.i.tion between teams. Each student was then shown slides and fabricated biographical information about his teammates and his compet.i.tors on the other team, and asked to rate how he felt about the other players.

The differences between introverts and extroverts were remarkable. The introverts a.s.signed to the cooperative game rated all players-not just their compet.i.tors, but also their teammates-more positively than the introverts who played the compet.i.tive game. The extroverts did just the opposite: they rated all players more positively when they played the compet.i.tive version of the game. These findings suggest something very important: introverts like people they meet in friendly contexts; extroverts prefer those they compete with.

A very different study, in which robots interacted with stroke patients during physical rehabilitation exercises, yielded strikingly similar results. Introverted patients responded better and interacted longer with robots that were designed to speak in a soothing, gentle manner: "I know it is hard, but remember that it's for your own good," and, "Very nice, keep up the good work." Extroverts, on the other hand, worked harder for robots that used more bracing, aggressive language: "You can do more than that, I know it!" and "Concentrate on your exercise!"

These findings suggest that Greg and Emily face an interesting challenge. If Greg likes people more when they're behaving forcefully or compet.i.tively, and if Emily feels the same way about nurturing, cooperative people, then how can they reach a compromise about their dinner-party impa.s.se-and get there in a loving way?

An intriguing answer comes from a University of Michigan business school study, not of married couples with opposite personality styles, but of negotiators from different cultures-in this case, Asians and Israelis. Seventy-six MBA students from Hong Kong and Israel were asked to imagine they were getting married in a few months and had to finalize arrangements with a catering company for the wedding reception. This "meeting" took place by video.

Some of the students were shown a video in which the business manager was friendly and smiley; the others saw a video featuring an irritable and antagonistic manager. But the caterer's message was the same in both cases. Another couple was interested in the same wedding date. The price had gone up. Take it or leave it.

The students from Hong Kong reacted very differently from the Israeli students. The Asians were far more likely to accept a proposal from the friendly business manager than from the hostile one; only 14 percent were willing to work with the difficult manager, while 71 percent accepted the deal from the smiling caterer. But the Israelis were just as likely to accept the deal from either manager. In other words, for the Asian negotiators, style counted as well as substance, while the Israelis were more focused on the information being conveyed. They were unmoved by a display of either sympathetic or hostile emotions.

The explanation for this stark difference has to do with how the two cultures define respect. As we saw in chapter 8, many Asian people show esteem by minimizing conflict. But Israelis, say the researchers, "are not likely to view [disagreement] as a sign of disrespect, but as a signal that the opposing party is concerned and is pa.s.sionately engaged in the task."

We might say the same of Greg and Emily. When Emily lowers her voice and flattens her affect during fights with Greg, she thinks she's being respectful by taking the trouble not to let her negative emotions show. But Greg thinks she's checking out or, worse, that she doesn't give a d.a.m.n. Similarly, when Greg lets his anger fly, he a.s.sumes that Emily feels, as he does, that this is a healthy and honest expression of their deeply committed relationship. But to Emily, it's as if Greg has suddenly turned on her.

In her book Anger: The Misunderstood Emotion, Carol Tavris recounts a story about a Bengali cobra that liked to bite pa.s.sing villagers. One day a swami-a man who has achieved self-mastery-convinces the snake that biting is wrong. The cobra vows to stop immediately, and does. Before long, the village boys grow unafraid of the snake and start to abuse him. Battered and bloodied, the snake complains to the swami that this is what came of keeping his promise.

"I told you not to bite," said the swami, "but I did not tell you not to hiss."