Marriage can be a wonderful life-long partnership between two people that often results in raising children, shared experiences, better health, and, ultimately, happiness. It can also fall apart, leading to divorce, lifelong trauma for you and the kids, as well as loneliness, which has all the hallmarks of a nationwide epidemic. 47% of Americans do not have meaningful interactions with friends or family on a daily basis, says a 2018 survey by the nationwide insurer Cigna.

Making marriage last requires both work and an understanding of the ebbs and flows that are a part of any relationship. According to a recent study "Personality Change Among Newlyweds" by the researchers from the University of Georgia and the University of California, achieving marital satisfaction also calls for understanding how the personalities of the partners inevitably change over time. The scientists found that personality changes begin right from the onset of a marriage, as partners adjust to their new roles. The most significant difference that takes place is that husbands and wives become less agreeable.

By studying 169 newlywed heterosexual couples for 18 months after marriage, the researchers identified some clear and measurable changes. Husbands, it turned out, became more conscientious, while wives became less anxious and depressed, exhibiting less "neuroticism". For husbands, the changes resulted from working harder and trying to become more responsible. The wives were less prone to emotional swings due to feeling more secure with stable attachments. 

On the flip side, husbands became less extroverted, spending more time at home. And both husbands and wives became less patient with each other and more disagreeable. One explanation for this - once the courtship period is over, old habits can come back. 

According to a theory by the best-selling relationship self-help guru, Harville Hendrix in the book "Getting the Love You Want," there are stages to marriage. Romantic Love, the first stage, has couples bringing out the best in each other. After that sweetest of periods, a Power Struggle follows. During that difficult stage, life is much more worrisome and couples bring out the worst in each other, explains the theory David Woodfellow, Ph.D, a couples therapy expert. 

The goal of a good marriage is then to move past the inevitable power struggle towards Real Love. If you're wondering, the average length of a marriage that ends in divorce in the U.S. is eight years. As the new study shows, figuring out how to deal with the changes while not getting mired in a power struggle may be the direction that can keep a marriage going.

You can read the study here, published in Developmental Psychology. The research team included Justin A. Lavner, Brandon Weiss, and Joshua D. Miller from the University of Georgia as well as Benjamin R. Karney from the University of California, Los Angeles.