The choice of a long-term romantic partner is one of the most important decisions in people’s lives. But how do humans do that?
From both personal experience and psychological research, we know that there are universally preferred characteristics in a potential mate, such as intelligence, physical attractiveness, agreeableness, etc. However, this is not the whole (love) story.
When choosing a partner, it is not only important to us to catch the good-looking, smart, and nice girlfriend/boyfriend, but that he/she is also our “match.” The meaning of a “match” comes in two forms, which are reflected in folk sayings, “Birds of feather flock together,” and “Opposites attract.”
Everyone has heard of these wise words, and many use them when describing couples that they know, choosing whichever is suitable at the time. Both are frequently depicted in romantic comedies, where the protagonists either fall in love because they adore identical music, movies, hobbies, have the same opinions on basically anything, and are also similarly attractive; or they fall in love precisely due to their opposite natures, backgrounds, and attitudes (but rarely looks). These two ideas on how people pair up are completely incongruent, and both of them cannot be true. So, what does science have to say about this?
Many, many studies showed that people mostly form romantic bonds with partners similar to them. This can be said about age, education, socioeconomic status, attractiveness, intelligence, attitudes, values, physical characteristics like height and weight, but also more surprising ones like finger length. When it comes to personality, the findings are pretty much the same, although couples are not as similar in their character as they are in age, socioeconomic status, education, attitudes, and intelligence.
Now, there are many reasons why such resemblances between couples could be observed, and this does not mean that people are purposefully trying to find their exact replica inside another body. For example, people with similar personalities could have similar interests, and hence, more opportunities to meet and mate. This is only one of many possible explanations, which we will not get into.
This is mainly because the focus of our study titled “The effects of similarity in the Dark Triad traits on the relationship quality in dating couples,” published recently in the journal Personality and Individual Differences was on the possible outcomes of couples’ similarity in an interesting set of personality traits. Namely, we wanted to find out if similarity in personality could predict the quality of the relationship. Previous studies have found this to be the case. For example, couples that are more similar in the Big5 personality traits (i.e., openness, conscientiousness, extraversion, agreeableness, and neuroticism) were more satisfied with their relationships.
In our research, we focused on the so-called Dark Triad of personality and its relation to the quality of relationship. The Dark Triad includes psychopathy, narcissism, and Machiavellianism. Now, none of these refers to psychopathology, and although obviously socially aversive, they are considered normal. Of course, psychopathy as a personality trait is different from psychopathy in its clinical form and is a much, much milder version of it. This is also true for narcissism in comparison to Narcissistic Personality Disorder.
People with high levels of psychopathy do not empathize with other people, are callous, often have antisocial tendencies (for example to cheat, lie, steal) and seek excitement and thrill. Those of us with a pronounced narcissistic trait have an enhanced image of themselves and often believe they are better than other people are, deserve more, and are offended if they do not get it. They seek the spotlight and enjoy it. Finally, the ones high on Machiavellianism are more strategic in their malevolence than are those high on other two Dark Triad traits. Because they are not as impulsive, they are inclined to manipulative and exploitative behavior. They are often quite cynical, with a negative worldview, always prepared for the less gracious side of human nature.
People with more extreme levels of these three traits are not the best romantic partners. It is not hard to imagine why, but here are a few examples. Psychopathy is associated with rape-enabling attitudes, narcissism with the belief that one has better alternatives, and Machiavellianism with engaging in a relationship for status and resources.
So, in order to test if similarity in these dark traits is also beneficial to the quality of a relationship, we asked 100 young urban heterosexual couples who were dating for at least six months to complete the questionnaires that measure psychopathy, narcissism, and Machiavellianism, as well as questionnaires for assessing different aspects of the quality of their relationship.
Our results showed that only men’s psychopathy predicted the relationship quality of both men and women. This means that men with higher levels of this trait do not think that their relationship is a very good one. Their partners seem to agree; when a woman has a boyfriend with a pronounced trait of psychopathy, she will not be too content with the state of affairs. It is quite clear why a woman with such an insensitive partner might not feel that she has hit the jackpot, but what about a man? Well, this could be the result of the basic incompatibility of psychopathy and being committed to an intimate relationship, for research has found that men with high levels of this trait seek short-term flings, with an emphasis on the sexual aspect.
And what about similarity? Well, the so-called “profile similarity” in narcissism seems to be beneficial for the relationship quality of both men and women. This means that the partners do not necessarily have to have the same level of narcissism, but their responses to many questions that are asked to measure this trait have to be in sync. So, it is more important for the quality of their relationship for a man and a woman to have the same “kind of narcissism” (e.g., they both like to be in the center of attention, but they do not think they have great bodies) than to be equally narcissistic altogether.
A similarity in psychopathy was found to be beneficial for women’s relationship quality. Or, it would be more accurate to say that the more a man and a woman differed in their level of psychopathy, the lower her rating of the relationship. This relationship between a couple’s resemblance in psychopathy and relationship quality is actually curved, which means that a woman’s relationship quality decreases rapidly the larger the difference between her and her partner’s psychopathy. Incompatibility in personality can create disparities in perceptions, expectancies, and behaviors, which hinder reinforcement and understanding between partners. Since women are something like relationship thermometers, their judgment of relationship quality might be especially sensitive to differences between themselves and their partners.
Finally, both women’s and men’s relationship quality suffered when both of them had high Machiavellianism. In other words, couples who have similar but low levels of this trait reported a higher quality relationship than couples who are equally similar but on the high end of Machiavellianism. This effect was especially pronounced in women, for their quality decreased rapidly as the Machiavellianism levels of both partners increased. This finding could be understood if we remind ourselves of the manipulative nature of Machiavellistic individuals.
To conclude, it is definitely better not to meddle with all those attractive bad boys and girls. Especially if you are a girl, and he is high on the psychopathy side. However, if you happen to be one of them, your relationship will probably be the best possible if you and your partner have similar “kind of narcissism,” similar levels of psychopathy, and opposite levels of Machiavellianism.
If you would like to see where you stand on the darkness continuum, follow the links below:
… for psychopathy – https://openpsychometrics.org/tests/LSRP.php
… for narcissism – https://openpsychometrics.org/tests/NPI/
… for Machiavellianism – https://openpsychometrics.org/tests/MACH-IV/
… for the whole Dark Triad – https://openpsychometrics.org/tests/SD3/
These findings are described in the article entitled The effects of similarity in the dark triad traits on the relationship quality in dating couples, recently published in the journal Personality and Individual Differences. This work was conducted by Igor Kardum, Jasna Hudek-Knezevic, and Nermina Mehic from the University of Rijeka, and Melane Pilek from the Josip Juraj Strossmayer University of Osijek.