Testosterone and Teenage Boys: What the Research Says

Why puberty is about more than hormones, and why blaming testosterone can mean missing the boy behind the behaviour.

There's a familiar narrative surrounding teenage boys. They become moody, argumentative, withdrawn or impulsive, and we put it down to their hormones. Testosterone gets the blame for everything from slammed bedroom doors to aggressive behaviour, risk-taking and an apparent inability to communicate how they're feeling.

But what if we are missing something important?

What if the changes we see in teenage boys are not simply the result of testosterone surging through their bodies, but part of a much more complex process involving their developing brains, emotional experiences, relationships and the expectations placed upon them?

As a psychotherapist working with men and boys, and someone who spent over 20 years teaching and mentoring teenage boys, I believe we need to look beyond the behaviour we see and be more curious about what might be happening underneath it.

Adolescence is a period of extraordinary change. Boys are navigating physical development, shifting relationships, emerging sexuality, questions about identity and an increasing desire for independence. At the same time, they're learning how to manage emotions that can feel unfamiliar, overwhelming or difficult to express.

Testosterone is part of that picture, but it's far from the whole story.

This is the first in a series of three articles exploring what's happening for boys during adolescence. Here, I look at what the research tells us about testosterone - and what it doesn't.

What happens to testosterone during puberty?

Testosterone is a hormone produced mainly in the testes, with smaller amounts produced by the adrenal glands. It plays an important role in male sexual development, muscle and bone growth, reproductive function and other processes in the body.

During puberty, testosterone production increases significantly. A systematic review published in the Journal of Adolescent Health in 2014 described a roughly 30-fold increase in testosterone production during male puberty.

This increase contributes to many of the physical changes associated with adolescence, including a deepening voice, increased muscle mass, the development of facial and body hair, and sexual maturation.

However, testosterone isn’t simply a hormone responsible for physical development. It also interacts with the brain and is involved in motivation, social behaviour and emotional development.

What remains less clear is precisely how changes in testosterone influence a teenage boy's mood and behaviour.

The 2014 review examined 27 studies involving boys aged 9 to 18. Although some studies identified links between testosterone levels and aggression, the researchers concluded that there was a lack of high-quality long-term evidence to show that changing testosterone levels during puberty directly caused changes in mood or behaviour.

A more recent systematic review, published in eClinicalMedicine in 2024, examined 55 studies exploring pubertal hormones and emotional wellbeing. It identified associations between testosterone and certain behaviours, including aggression and rule-breaking, but concluded that the evidence for a direct causal relationship remained weak.

In other words, testosterone may influence how boys experience and respond to their environment, but it does not determine how they behave.

This distinction is key. When we attribute a boy's anger, withdrawal or distress entirely to testosterone, we risk overlooking the emotional, relational and environmental factors that may be contributing to his experience. We may also miss opportunities to help him understand what he’s feeling and develop healthier ways of responding.

Testosterone, anger and the myth of the aggressive teenage boy

One of the most persistent assumptions about testosterone is that it makes boys aggressive.

We often hear phrases such as 'raging hormones' or 'testosterone-fuelled behaviour' used to explain teenage boys becoming confrontational, competitive or difficult to manage.

Whilst there is some evidence linking testosterone with aggression, the relationship is considerably more complex than these expressions suggest.

A 2025 systematic review examining testosterone, cortisol and aggression in children and adolescents found that most research results were inconclusive or mixed. Some studies identified a modest link between higher testosterone levels and aggression during adolescence, but this relationship was influenced by other factors, including stress and the social environment.

Research has also suggested that the relationship between testosterone and aggressive behaviour may depend on a young person's experiences and the environment in which they're growing up. For example, one study found that harsh discipline influenced the relationship between testosterone and aggression in young people. The findings suggest that the same biological characteristics may be associated with different behaviour depending on the social and relational context.

This challenges the idea that aggression is an inevitable consequence of male puberty. It also raises an important question:

If a teenage boy is becoming increasingly angry, what might that anger be communicating?

Anger is an emotion in its own right, but it can also emerge alongside feelings of shame, fear, rejection, frustration, helplessness or vulnerability.

A young man who feels excluded by his friends may respond with anger rather than acknowledge that he feels hurt. A boy struggling academically may become argumentative when questioned about his schoolwork. A teenager who feels overwhelmed by expectations at home may withdraw or become defensive when someone tries to talk to him.

These are possibilities rather than explanations that apply to every boy, but they illustrate why curiosity matters. If we respond only to the anger, we may never discover what else is happening.

That doesn’t mean accepting aggression or removing responsibility for harmful behaviour. A teenage boy can be held accountable for his actions while also being supported to understand the feelings and experiences that contributed to them. These two things are not mutually exclusive.

The teenage brain is changing too

While testosterone levels are increasing during puberty, the adolescent brain is also undergoing significant development.

The parts of the brain involved in processing emotion, motivation, reward and decision-making continue to develop throughout adolescence. The prefrontal cortex, which plays an important role in planning, considering consequences and regulating behaviour, continues to mature into early adulthood.

This doesn’t mean that teenage boys are incapable of making thoughtful decisions or managing their emotions. Rather, their capacity for emotional regulation and decision-making is still developing, particularly in situations involving heightened emotion, social pressure or uncertainty.

Pubertal hormones may interact with these developing systems, but researchers continue to investigate precisely how.

Consider a teenage boy who has been embarrassed in front of his friends.

He may experience a strong emotional response, particularly if he feels that his social standing or sense of belonging has been threatened. In that moment, his desire to defend himself may become more immediate than his ability to consider the longer-term consequences of his response. He might lash out verbally, walk away or do something impulsive.

Later, when the intensity of the emotion has reduced, he may recognise that his response was unhelpful. He may even feel ashamed of how he behaved. Yet when questioned about what happened, he might struggle to explain it.

This is where adults can make a significant difference. Rather than expecting boys to demonstrate emotional regulation without having been supported to develop it, we can help them recognise what happens in their bodies, identify their emotions and practise responding differently.

Looking beyond the hormones

Testosterone plays an important role in the physical changes of male puberty, and research suggests it may influence aspects of emotional and social development. But it cannot explain a boy's individual experiences, the relationships that shape him or the emotions he may be struggling to understand.

When we reduce teenage boys' behaviour to hormones, we risk overlooking the person behind the behaviour.

In the second article in this series, Why Teenage Boys Struggle to Say What They Feel, I’ll explore what may be sitting beneath the anger, withdrawal and mood changes we so often put down to testosterone.

Research and further reading

Duke, S. A., Balzer, B. W. R. and Steinbeck, K. S. (2014). Testosterone and its effects on human male adolescent mood and behavior: a systematic review. Journal of Adolescent Health. 55(3), 315-322.

Luo, D., Dashti, S. G., Sawyer, S. M. and Vijayakumar, N. (2024). Pubertal hormones and mental health problems in children and adolescents: a systematic review of population-based studies. eClinicalMedicine. 76, 102828.

Cima, M. et al. (2025). A systematic review of the relationship between cortisol, testosterone, and aggression in children and adolescents. Aggression and Violent Behavior. 82, 102051.

Chen, F. R., Raine, A. and Granger, D. A. (2018). Testosterone and proactive-reactive aggression in youth: the moderating role of harsh discipline. Journal of Abnormal Child Psychology. 46(8), 1599-1612.

Forbes, E. E. and Dahl, R. E. (2010). Pubertal development and behavior: hormonal activation of social and motivational tendencies. Brain and Cognition. 72(1), 66-72.