Dr. Shahar Madjar

The idea that opposites attract is appealing. It is romantic. It is rooted in familiar love stories: Cinderella, Pretty Woman, and The Beauty and The Beast, just to name a few. It is a comforting idea: the less fortunate people can still mingle with the lucky ones. The blessings in this world will spread more evenly. Harmony might prevail.

The question of whether opposites attract calls for some critical thinking. I ask myself two questions: What does ‘opposites’ mean? And what are we talking about when we are talk about attraction?

Are we talking complete opposites? In terms of Geography, for example, a complete opposite romantic partner would be a person who lives, or at least has come from the other side of the world. He, or she was brought up in a different culture, belongs to a different class, believes in a different God, and holds opposite values and political affiliations. I imagine a straight line that passes from one spot on Earth, through Earth’s center, and reaches another point on Earth that is diametrically opposite to it (in Geography, such two points are called antipodes). For a person living in the Upper Peninsula of Michigan, this spot falls in the middle of the ocean. If you tried to meet your complete ‘geographical opposite,’ you will find yourself surrounded by water, cold, and alone.

I quickly calculated that a person’s chance to meet their complete opposite is even slimmer than that of finding their perfect soul mate. What we are talking about, then, isn’t a question of complete opposites. Instead, ‘opposites’ relates to only some traits, and only to some degree.

The second question is ‘What are we talking about when we talk about attraction?’ Are we talking about physical attraction that leads to a casual, brief love affair ? A spiritual connection? An attachment that results in a long, committed relationship?

In August 2023, Tanya B. Horowitz, a PhD student at the University of Boulder, Colorado, and her colleagues published an article in Nature Human Behavior. The researchers analyzed correlations between multiple different traits among partners. It was a meta-analysis–a study that combines and analyzes the results of several other research studies. She used two different sources for her calculations. The first was a group of 199 previously published studies where she examined 22 traits. She also calculated the correlations between 133 traits in a group 79,074 couples in the UK Biobank–a large database that collects genetic and lifestyle information from half a million participants in the United Kingdom (participation is voluntary and the data is de-identified). The partners in all of these studies were either engaged, married, or lived together as couples (sometimes co-parenting children).

The traits Horowitz studied were diverse and included health related traits and anthropometric traits (such as overall health, presence of chest pain, height, weight, or hair color), demographic traits (year of birth and birthplace), psychological traits (financial security and happiness), substance use, and behavioral traits (the frequency of visits to family and friends, and time spent on the computer).

The article describes the correlations among partners but doesn’t provide clear information on the characteristics of the relationships themselves. Where these short, or long term relationships? I couldn’t find an answer. I assume that most participants were in a longer-term relationship. Also, these were all male-female couples (the study didn’t include same-sex couples).

The results indicate that the great majority (82%-89%) of the traits that were examined were similar among partners and only 3% of the traits ranked as substantially different.

The couples were closely matched in their political and religious views, level of education, and some measures of IQ. Heavy smokers and heavy drinkers tended to partner with one another.

The couples were also similar in their birth year, and the number of sexual partners they had.

In only a minority of traits the association was weak: early risers tended to pair up with night owls. People who worry a lot tended to pair with those who worry less. And left-handed people tended to match with right-handed people (not surprising because 85%-90% people are right handed which makes it difficult for a left-handed person to match with another left-handed person).

Despite the stories depicting opposites that attract, the findings in Horowitz’s study just make sense. Individuals are much more likely to find their partners in circumstances similar to their own: at the same neighborhood, at the same college, meeting with the same narrow group of friends and like-minded people. It is likely, also, that couples who stayed together, grew more similar to one another and that those who were “opposite enough,” grew even further apart. They are no longer in a relationship and therefore didn’t participate in this study. The study conclusion might therefore read: birds that flock together–for long enough–share similar feathers.

Shahar Madjar, MD, MBA, is a urologist and an author. He practices in Michigan, at Schoolcraft Memorial Hospital in Manistique, and in Baraga County Memorial Hospital in L’Anse. Find his books on Amazon. Contact him at smadjar@yahoo.com.