Higher testosterone linked to reduced closeness in social relationships

New research suggests that hormones such as testosterone and cortisol may be associated with closeness in social relationships.

The study of 166 college students, published in the journal Psychoneuroendocrinology, found that people with relatively lower cortisol and testosterone levels were more likely to feel closer to a stranger they had a conversation with. Higher testosterone was associated with lower closeness.

PsyPost interviewed the study’s corresponding author, Sarah Ketay of the University of Hartford. Read her responses below:

PsyPost: Why were you interested in this topic?

Ketay: Close relationships are linked with happiness, well-being and even lower mortality. Understanding the biological correlates of new friendships allows us to see what factors are associated with closeness as it develops. There’s a growing body of literature suggesting testosterone and cortisol may have detrimental effects on long-term romantic relationships, but this is the first study to examine how these hormones operate in friendship formation.

What should the average person take away from your study?

An important take-away is that this work suggests hormones shape our social interactions, even with people we’ve just met. Further, our daily social interactions also can alter our hormone levels. At the same time, people have relatively stable hormone profiles. These hormone profiles may also impact how we form new friendships and become close to others.

Are there any major caveats? What questions still need to be addressed?

The main caveat is that this research is correlational, and therefore no causal conclusions can be made. To explore if hormones are causally linked with closeness, we would need to manipulate hormonal levels. With testosterone, this can be done in many ways, such as through gels, patches, or even placing drops or tablets into the mouth, and several research labs are employing this to manipulate hormone levels in controlled psychological studies.

Is there anything else you would like to add?

We had two conditions in our study, one that encouraged high self-disclosure and another that encouraged low-self-disclosure. Across both samples, people reported feeling quite close to one another. This is heartening, as even in our society where loneliness, social isolation and technology can get in the way of our relationships, most people become close to one another, given the opportunity.

The study, “The roles of testosterone and cortisol in friendship formation“, was also co-authored by Keith M. Welker and Richard B. Slatcher.