Oxytocin is a hormone that promotes bonding during the early stages of relationship development, positive feelings toward relationship partners1, including feelings of trust.2 In fact, oxytocin has been implicated in a variety of positive relationship behaviors, including attachment, social memory, sexual behavior, and orgasm, as well as maternal caring and bonding behaviors.3 As a result, the media often refers to oxytocin as the “cuddle hormone.” However, recent research suggests that the so-called “cuddle hormone” may have a dark side by increasing relationship violence.
How They Did It
Researchers randomly assigned 93 undergraduate students to receive a nasal spray containing either (a) oxytocin or (b) a saline solution (i.e., a placebo spray). Importantly, the administration of the spray was double-blind; neither the researcher nor the participant knew which spray the participant was receiving. Following the spray, researchers provoked participants in an attempt to raise stress levels and establish a context for aggression. The provocations involved giving a brief speech to an audience who disagreed with the speech and experiencing a “cold pressor task” in which extreme cold is applied to the participant’s forehead (resulting in moderate physical pain). Participants then completed a measure of trait aggression (i.e., how much the person is naturally inclined toward aggression) as well as a measure of how likely individuals were to be aggressive toward their partners that asked about the likelihood of engaging in several behaviors toward their romantic partners (e.g., throwing things, twisting their arm/hair, shoving).
What They Found
Those exposed to oxytocin had a greater inclination toward interpersonal violence than those exposed to the placebo. Also, those who had higher trait aggression reported a greater inclination toward interpersonal violence than those with lower trait aggression. These variable also combined or interacted in an interesting way. Specifically, oxytocin increased participants’ inclination toward interpersonal violence only among those who were naturally inclined toward aggression (i.e., those high in trait aggression). However, among those with lower trait aggression, oxytocin did not increase inclination toward interpersonal violence.
When interpreting these results it is important to point out that the observed differences between oxytocin conditions could be due to how the researchers measured interpersonal violence. That is, it is possible that oxytocin increased willingness to more honestly and accurately report their actual inclination, rather than increasing participant’s perceived likelihood of engaging in interpersonal violence. In other words, those receiving oxytocin may have simply been more honest, while those not receiving oxytocin gave answers that made them look good.
What the Results Mean For You
Based on these results, if you’re the type of person who is not generally aggressive, oxytocin probably won’t make you violent. However, if you are someone who tends to be more aggressive, experiencing a rush of oxytocin may exacerbate your natural aggressive tendencies. Admittedly, the fact that the so-called “cuddle hormone” can lead a person to non-cuddly behaviors like grabbing or slapping a romantic partner seems counterintuitive. One potential explanation is that oxytocin drives individuals to seek out their partners, and that for those inclined toward aggression, the way to achieve closeness isn’t always kind and gentle. In fact, we know from other research that individuals employ “mate retention strategies” designed to decrease the chances that their romantic partners interact with new potential partners.5 In this vein, oxytocin may encourage an aggressive individual to exert control, dominance, and perhaps violent behaviors in an attempt to keep a partner close. We shouldn’t blame oxytocin too much, though, since it doesn’t seem to have negative effects for those with low trait aggression. Rather, the take-home message is that this research provides a pretty good reason to avoid relationship partners who are high in trait aggression.
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1Schneiderman, I., Zagoory-Sharon, O., Leckman, J. F., & Feldman, R. (2012). Oxytocin during the initial stages of romantic attachment: Relations to couples’ interactive reciprocity. Psychoneuroendocrinology, 37, 1277–1285.
2Van IJzendoorn, M. H., & Bakermans-Kranenburg, M. J. (2012). A sniff of trust: Meta-analysis of the effects of intranasal oxytocin administration on face recognition, trust to in-group, and trust to out-group. Psychoneuroendocrinology, 37, 438–443.
3Lee, H., Macbeth, A. H., Pagani, J. H., & Young 3rd, W. S. (2009). Oxytocin: The great facilitator of life. Progress in Neurobiology, 88, 127–151.
4DeWall, C., N., Gillath, O., Pressman, S. D., Black, L. L., Bartz, J. A., Moskovitz, J., & Stetler, D. A. (2014). When the love hormone leads to violence: Oxytocin increases intimate partner violence inclinations among high trait aggressive people. Social Psychological and Personality Science (Online). doi: 10.1177/1948550613516876
5Buss, D. M., & Shackelford, T. K. (1997). From vigilance to violence: Mate retention tactics in married couples. Journal of Personality and Social Psychology, 72, 346–361.
Dr. Gary Lewandowski - Science of Relationships articles | Website
Dr. Lewandowski's research explores the self’s role in romantic relationships focusing on attraction, relationship initiation, love, infidelity, relationship maintenance, and break-up. Recognized as one of the Princeton Review’s Top 300 Professors, he has also authored dozens of publications for both academic and non-academic audiences.