Scientists are untangling the complex interplay between testosterone, aggression, and shame

Scientists have shed new light on the intricate relationship between hormones, shame, and aggression. A recent study, published in the journal Psychoneuroendocrinology, reveals that testosterone reactivity plays a pivotal role in moderating aggressive behavior among young men, especially when coupled with an individual’s tendency to experience feelings of shame.

Previous studies have explored the role of testosterone in aggression and the impact of shame on behavior, but this new research delves deeper into the interplay between these factors. The researchers were motivated by the need to explore how testosterone reactivity, which can fluctuate in response to social inclusion or exclusion, influences aggressive behavior, and how this might be moderated by an individual’s shame proneness.

“Being excluded is a painful but all too familiar experience for most people. Whether it involves the breakdown of a romantic relationship or even being ignored by a complete stranger, most people experience exclusion on a pretty regular basis,” said study author Lindsay Bochon, a PhD student at Simon Fraser University.

“Research has found that exclusion has some profound consequences for our overall mental health and well-being. Being excluded over a long period of time can lead to things like depression and anxiety, but even a short, seemingly benign experience of exclusion can affect our behavior. For example, a lot of research has found that people will often become more aggressive when they have been excluded.

“But why is this?” Bochon continued. “Since aggression has long been associated with the hormone testosterone, we wanted to examine whether changes in this social hormone could explain associations between exclusion and aggression. Some research has also shown that different personality traits can influence how testosterone affects behavior. So, we decided to look at the tendency to experience shame, as well.”

The research involved 199 male undergraduate students, with an average age of 19.54 years. These participants were recruited through a research participation program, and their involvement was voluntary.

To explore the effects of social exclusion, the researchers used a virtual ball tossing game called Cyberball. Participants were randomly assigned to either an inclusion or exclusion condition within this game. In the inclusion condition, they received an equal number of ball tosses from other players, while those in the exclusion condition received only two ball tosses at the beginning and were then ignored for the rest of the game.

Before and after the Cyberball game, participants provided saliva samples to measure their testosterone levels. Additionally, they completed questionnaires, including one to assess their shame proneness using the Experience of Shame Scale. This scale examined shame experiences related to different aspects of the self, actions, and physical characteristics.

Following the Cyberball game, participants engaged in a computer-based aggression task known as the Point Subtraction Aggression Paradigm (PSAP). In this task, they had the opportunity to “steal” points from a fictitious opponent by pressing specific keys, with no financial reward for themselves. This measure allowed researchers to assess aggressive behavior in a controlled setting.

Surprisingly, there were no significant differences in aggression levels between participants in the exclusion and inclusion conditions during the PSAP task. This suggests that social exclusion within the Cyberball game did not directly lead to increased aggression in this controlled setting.

The crucial finding came when the researchers examined the interplay between testosterone reactivity and the Cyberball conditions. In the inclusion condition, an increase in testosterone was associated with a decrease in aggression. However, in the exclusion condition, a decrease in testosterone was associated with a decrease in aggression. This suggests that testosterone reactivity moderated the relationship between exclusion and aggression.

When considering the role of shame proneness, the results became even more nuanced. For individuals low in shame proneness, exclusion was associated with lower post-Cyberball aggression when testosterone decreased. In contrast, those with low shame proneness who experienced an increase in testosterone showed higher post-Cyberball aggression. However, for individuals high in shame proneness, testosterone reactivity did not significantly impact aggressive behavior, regardless of the exclusion condition.

These findings suggest that the relationship between testosterone reactivity and aggression in social situations is highly complex and depends on individual differences in shame proneness. For those low in shame proneness, fluctuations in testosterone can significantly influence subsequent behavior in response to social exclusion or inclusion.

“The high-level take away from this study is that whether or not people behave aggressively after being excluded depends upon different personality and physiological characteristics,” Bochon told PsyPost. “In a sample of men, we found that there was a relationship between testosterone responses to exclusion and aggressive behavior, but only in individuals who experienced low levels of shame. For example, when testosterone decreased in response to exclusion, low shame men behaved less aggressively. However, when testosterone increased, low shame men behaved more aggressively.”

“Testosterone is often linked with behaviors, like aggression, that are intended to improve social status. When you are excluded, this is a signal that you have low status. You can’t be the leader of the group if you are not a part of it. So, increased testosterone may be linked to higher aggression as a way of regaining lost status. But if status cannot be regained, reductions in testosterone decrease potentially costly aggressive behaviors.”

“Interestingly, this relationship between testosterone and aggression was not found in men who experienced higher levels of shame,” Bochon explained. “People who consistently experience shame often feel threatened and will withdraw from social contact or act submissively. So, it’s possible that people with high levels of shame felt threatened and responded with withdrawal, regardless of their testosterone response and whether they were included or excluded. This would explain why there was no relationship found between these variables for high shame individuals.”

While this research provides valuable insights, there are limitations to consider. The Experience of Shame Scale used in the study focuses on avoidance and withdrawal responses to shame, representing only one aspect of shame. Future studies may benefit from exploring shame in a more multifaceted manner.

“Shame is a tricky concept,” Bochon said. “Whether you are discussing shame that is experienced in the moment, or shame that is felt chronically (i.e., a personality trait) can have different consequences for behavior. We focused on chronic levels of shame, but some research shows that transient shame can make people more willing to approach other people and socialize. So, it would be interesting to see whether measuring shame differently would affect the results.”

“In addition, we only measured men in this study, but women have testosterone too. Would they have the same relationship between exclusion, testosterone, and shame? This is a question that future research could potentially answer.”

The study, “Excluded and ashamed: Shame proneness interacts with social exclusion and testosterone reactivity to predict behavioral aggression“, was authored by Lindsay Bochon, Brian M. Bird, and Neil V. Watson.

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