What's Love Got to Do with It?

Romance, family, and big life events: they may seem disparate at first glance, but the Personality, Relationships, and Hormones Lab at U-M examines the ways they are intimately connected. Robin Edelstein, the lab’s principal investigator and a professor of psychology, dives into the ways in which our individual differences affect our bodies and, in turn, our relationships. 

LSA: What have you learned about some of the ways that personality types can play a role in romantic relationships?

Robin Edelstein: I see a few broad themes emerging from research on personality and romantic relationships: First, prosocial traits such as extroversion, emotional stability, and agreeableness are consistently associated with better relationship outcomes. Second, although our partners’ personalities do matter for relationship outcomes, our own characteristics and perceptions typically play a much larger role. So people might benefit more from focusing on their own contributions to a relationship (e.g. their reactions to a partner’s behavior) than from trying to change their partner’s personality or behavior. 

There’s still a lot that we don’t know about why people choose the partners that they do and why some relationships are more likely to thrive than others. Personality traits certainly play a role here, but likely in complicated ways that are best understood with intensive, longitudinal studies that can address how both personality traits and relationships change over time and across relationship partners.    

LSA: Some of your research has examined the role of avoidance. What have you found about how avoidance can affect relationships?

RE: One of the personality traits that I’ve focused on in my own work is “attachment avoidance,” or the extent to which people feel comfortable with closeness and intimacy. People who are more avoidant tend to find it difficult to get close to others and prefer to be more self-reliant and independent as opposed to interconnected with relationship partners. 

People who are less avoidant, on the other hand, find it easier to express emotion, are more comfortable with physical and emotional intimacy, and are better able to communicate their needs to their partners. I’m especially interested in how avoidant people maintain that distance from others, including how they navigate relationship stressors and transitions. We’ve found that more avoidant people are less likely to be in romantic relationships in the first place; they’re also less satisfied with and committed to the relationships they do find themselves in (as are their partners). We’ve also found that more avoidant people tend to pay less attention to information that might cause them distress, perhaps in an attempt to protect themselves from threats to their sense of self-sufficiency.  

I do want to note, though, that personality traits such as avoidance, while fairly stable over time, are not necessarily set in stone—meaning that there is potential for change. Work with one of my former graduate students, Bill Chopik, demonstrated that people generally become less avoidant with age and when they’re in high-quality relationships. Therapy can also be helpful. So there are ways for people to become less avoidant and more comfortable with closeness over time and with experience. 

LSA: There’s a lot of social media content about what makes people compatible. How is your research similar to or different from popular online compatibility tests like the Enneagram? 

RE: Popular media and our own lay intuitions have led many to assume that people are happier in relationships with partners who are more similar to them. But the scientific evidence for this assumption is actually quite limited. 

Although people do tend to be similar to their partners in many ways, particularly with respect to demographic characteristics (e.g., education, political orientation, race/ethnicity, income), it’s not clear that similarity alone predicts relationship success. One of my current doctoral students, Annika From, has been studying similarity and complementarity in romantic relationships; her findings suggest that whether people perceive themselves to be similar to their partners may be more important than their actual levels of similarity. These findings again suggest that our own perceptions may be more important for relationship outcomes than “reality.” 

I think it’s also important to note that “compatibility tests” and dating sites claiming to help you find your perfect match are not generally based on sound scientific research. We still have a lot to learn about why some relationships are more successful than others, and it’s unlikely that any simple measure is going to provide answers to long-standing questions about romantic compatibility. But I do think that these sorts of tests and quizzes can be informative insofar as they help people think about their own personalities and the ways that they might differ from their partner.  

LSA: What are some ways that our hormones affect intimacy, whether emotional or physical?

RE: My research has focused primarily on two hormones that are linked with close relationship processes: cortisol and testosterone. Cortisol is one of the body’s major stress hormones; it typically increases when people face physical or psychological stressors, especially stressors that involve other people. Chronically elevated cortisol levels can lead to physical health problems. 

Recent work with two of my current doctoral students, Annika From and Janae Sayler, suggests that experiences of racial discrimination may also increase daily cortisol levels, highlighting a pathway through which external stressors may impact physical health. We are also examining how relationship partners can help to mitigate the physiological effects of stress: People who are partnered tend to have lower cortisol levels than those who are unpartnered, and cortisol often decreases in the presence of a partner. Partners often help one another regulate their emotions, and these findings suggest that they may also help to buffer the physiological effects of stress.

Testosterone is a hormone most commonly associated with dominance, aggression, and competition. Although commonly thought of as a “male” hormone, testosterone plays an important role in physical development and behavior in both men and women. We’ve found that lower testosterone is associated with better outcomes in both romantic and parent-child relationships. For instance, people with lower testosterone report greater romantic relationship satisfaction and commitment, as do their partners. Among new parents, both men and women with lower testosterone (and those who show larger prenatal declines in testosterone) report being more involved in infant care and household labor.

Of course, our findings are specific to testosterone levels that are within a normative, healthy range; people with clinically low (or high) testosterone could experience difficulties in relationships that may require pharmacological intervention.

LSA: How do certain life milestones (e.g. parenthood) affect our relationships? 

RE: Major life events and transitions can affect relationships in a few ways: First, even events that are welcome and eagerly anticipated, such as buying a house or having a baby, can be quite stressful and disruptive to our daily routines. These kinds of external stressors can also increase distress within a relationship. Insofar as stress reduces people’s ability to cope and regulate their emotions, people may be less empathetic or patient with their partners. 

Second, major life events can change the way we think about ourselves and our relationships; for instance, new parents may be more focused on caring for their infant than nurturing their romantic relationship, which could lead to resentment or dissatisfaction down the road. 

Finally, major life events and stressors, particularly those surrounding pregnancy and parenthood, can have significant physiological effects. For instance, stress can increase cortisol, which is helpful in the short-term for managing demanding situations; however, chronic elevations in cortisol can take a toll on cognitive resources and physical health.

Illustration by Becky Sehenuk Waite

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