How Marriage Changes Your Personality

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It’s often said that married couples grow more alike over the years. But can marriage really change your personality? New research by University of Georgia psychologist Justin Lavner and his colleagues shows that people’s personalities do change, in predictable ways, within the first year and a half after tying the knot.

Psychologists are divided on the question of whether personality is innately determined by your genes or shaped by experiences in early childhood, with many believing it’s probably a combination of both nature and nurture. By adulthood, however, personality is usually established and doesn’t change greatly after that. Still, some research has shown that major life events can nudge personality in particular directions: For example, a strong introvert with a desire to teach can learn to be more extroverted in the classroom.

Marriage, of course, is one of the most important events in a person’s life. Since married couples have to find ways to get along on a daily basis, it’s perhaps not surprising that they’d experience changes in their personality as they adapt to partnered life. This is the hypothesis that Lavner and his colleagues tested.

For the study, 169 heterosexual couples were recruited to respond to questionnaires at three points in their marriage—at 6, 12, and 18 months. This way, the researchers could detect trends in personality change. At each point, the couples (working individually) responded to two questionnaires, one assessing marital satisfaction and the other measuring personality.

The most widely accepted theory of personality is known as the Big Five. This theory proposes that there are five basic personality dimensions. The Big Five are usually remembered with the acronym OCEAN:

1. Openness. How open you are to new experiences. If you’re high in openness, you like trying new things. If you’re low in openness, you’re more comfortable with what’s familiar.

2. Conscientiousness. How dependable and orderly you are. If you’re high in conscientiousness, you like to be punctual and keep your living and working spaces tidy. If you’re low in conscientiousness, you don’t get uptight about deadlines, and you’re comfortable in your cluttered environment.

3. Extraversion. How outgoing you are. If you’re high in extraversion, you like socializing with lots of other people. If you’re low in extraversion (that is, introverted), you like having time to yourself.

4. Agreeableness. How well you get along with others. If you’re high in agreeableness, you’re easygoing and happy doing what everyone else is doing. If you’re low in agreeableness, you’ve got to have things your way, no matter what the rest of us want.

5. Neuroticism. How emotionally stable you are. If you’re high in neuroticism, you experience big mood swings and can be quite temperamental. If you’re low in neuroticism, your mood is relatively stable, and you live your life on an even keel.

When the researchers analyzed the data after 18 months of marriage, they found the following trends in personality change among the husbands and wives:

• Openness. Wives showed decreases in openness. Perhaps this change reflects their acceptance of the routines of marriage.
• Conscientiousness. Husbands increased significantly in conscientiousness, whereas wives stayed the same. The researchers noted that women tend to be higher in conscientiousness than men, and this was the case with the husbands and wives in this study. The increase in conscientiousness for men probably reflects their learning the importance of being dependable and responsible in marriage.
• Extraversion. Husbands became more introverted (lower in extraversion) over the first year and a half of marriage. Other research has shown that married couples tend to restrict their social networks compared to when they were single. This drop-in extraversion probably reflects that trend.
• Agreeableness. Both husbands and wives became less agreeable over the course of the study, but this downward trend is especially noticeable for the wives. In general, women tend to be more agreeable than men. This data suggests that these wives were learning to assert themselves more during the early years of marriage.
• Neuroticism. Husbands showed a slight (but not statistically significant) increase in emotional stability. The wives showed a much greater one. In general, women tend to report higher levels of neuroticism (or emotional instability) than men. It’s easy to speculate that the commitment of marriage had a positive effect on the wives’ emotional stability.

It probably comes as no surprise that marital satisfaction went downhill for both husbands and wives over the course of the study. By 18 months, the honeymoon was clearly over. However, the researchers did find that certain personality traits in husbands or wives predicted how much their marital satisfaction decreased.

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• Husbands who were high in openness at the start of the marriage showed little change in marital satisfaction, while those who were low in openness experienced the greatest drop in conjugal bliss. Perhaps high-openness husbands found ways to keep the relationship exciting.
• Wives who were low in neuroticism at the beginning also showed little change in marital satisfaction, while those who were high in neuroticism were much less happy after 18 months. This makes sense, since low neuroticism means living life on an even keel. Meanwhile, the high-neuroticism wives probably experienced an upward swing in positive mood around their wedding day with a return to a normal, less happy state afterwards.
• Likewise, husbands whose wives were low in neuroticism remained happy in their marriages after a year and a half. No doubt the emotional stability of their wives provided a stable base for these husbands.

With correlational data like this, it’s impossible to say that getting married caused these changes in personality. Most of the couples in this study were in their 20s, a time when other major life changes were occurring as well—you mature, start a career, and have children, all of which could affect your personality. So the researchers also tested whether the following variables could predict the personality changes they observed.

• Age: Those who married later showed similar personality changes to those who married younger. This suggests that maturity isn’t the only explanation for a personality change.
• Cohabitation before marriage: Those who cohabited before marriage showed the same personality changes as those who only started living together after marriage—with one exception. Women who cohabited with their future husbands before marriage exhibited low levels of neuroticism at the beginning of the marriage, and this emotional stability endured throughout the course of the study. Two possible explanations come to mind: 1) The period of cohabitation helped these women become more emotionally stable, so they were better prepared for married life; and 2) men ditched the girlfriends they were living with if they found them to be emotionally unstable, but committed to marriage otherwise.
• Parenthood: Some of the couples in the study became parents during the time period of observation. However, they didn’t differ significantly in their changes in personality compared with those who didn’t become parents. While parenting is definitely a stressful and life-changing event, it doesn’t affect personality in the way that getting married does.

Since none of these variables account for the data, the researchers maintain it’s likely that getting married is the cause of the personality changes they observed. These changes probably involve responses to the repetitive demands of a committed relationship. While they may not keep the flames of passion ablaze, they probably do reflect adjustments husbands and wives make as they negotiate patterns of behavior that will make their marriages sustainable.

If you’re thinking of getting married, you can expect your partner to change, but maybe not in ways you were expecting. Still, the best predictor of whether a marriage will thrive is the personalities of the two partners as they enter into the relationship. Happy, emotionally stable couples make for happy, emotionally satisfying marriages. But when partners bring emotional baggage into the relationship, the journey is likely to be bumpy.