Select your language

Suggested languages for you:
Log In Start studying!
StudySmarter - The all-in-one study app.
4.8 • +11k Ratings
More than 3 Million Downloads
Free
|
|

All-in-one learning app

  • Flashcards
  • NotesNotes
  • ExplanationsExplanations
  • Study Planner
  • Textbook solutions
Start studying

Testosterone Research

Save Save
Print Print
Edit Edit
Sign up to use all features for free. Sign up now
Testosterone Research

Testosterone functions as an androgen (a hormone that plays a role in the development of male characteristics) and as an anabolic steroid (protein building for muscle). It is produced in the gonads (the male testes and the female ovaries) and the adrenal cortex, although it’s produced at a much smaller rate in the female ovaries. Hormones act as chemical messengers in the body, stimulating various cells and tissues depending on the reason behind the testosterone secretion.

The hypothalamus regulates testosterone production in the brain, and the pituitary gland acts as the overseer of the gonads and adrenal glands.

Testosterone also enables secondary ‘male’ characteristics, such as muscle and skeletal growth, as well as body hair and facial hair. These characteristics tend to be less developed when there is not enough testosterone in the body of males undergoing puberty.

Did you know? Testosterone is also important in reproductive systems such as sex drive and sexual health.

Testosterone Research Chemical form of testosterone StudySmarterThe chemical form of Testosterone, commons.wikimedia.org.

How does testosterone affect aggression?

Testosterone is one of the main driving forces behind the actualisation of aggressive behaviours in psychology (Batrinos, 2012). These can be:

  • Anger (thoughts, feelings).

  • Verbal aggressiveness.

  • Dominance.

  • Competitiveness.

  • Physical aggression.

Amongst other similar traits.

Testosterone Research Illustration of a boxer StudySmarterA person with boxing gloves and an aggressive stance, flaticon.com.

Fluctuating levels of testosterone can have various effects on the body and brain. Testosterone is also closely linked with the brain regions associated with how aggressive behaviours come about—namely, the amygdala.

Testosterone activates the amygdala, enhancing its resistance to regulation from the prefrontal cortex (PFC), and increasing its emotional reaction to stimuli (Batrinos, 2012). Thus, when something threatening comes along and stimulates the amygdala, the person will have an emotional response. High testosterone levels mean that the areas of the brain that usually ‘calm down’ the amygdala if the threat is not as serious as once thought, are no longer as effective. As a result, emotions run higher and aggressive behaviours increase.

Usually, testosterone is mediated by different brain regions, as well as cortisol and serotonin. In healthy, normal levels, aggression occurs and is mediated correctly, so people can react appropriately to different situations. Without this mediation, aggressive behaviours are more likely to occur.

High levels of testosterone are linked to aggressive behaviours.

In animals, testosterone affects behaviours differently. However, it is usually linked to aggressive behaviours, such as defending territory and ensuring the male members of the species are the ones to mate with the females.

The Basal model of testosterone

The Basal model of testosterone suggests that testosterone changes a person’s level of dominance. In this model, testosterone is a stable factor in a person, and it determines how dominant they are as a result. According to the model, testosterone can be measured to predict aggressive behaviours.

  • The more testosterone they produce, the more dominant and competitive an individual may be. If a male has high levels of testosterone, he may take part in antisocial behaviour, such as fighting.

Mazur (1995)

In this study, researchers measured 4179 Vietnam veterans’ hormone levels (testosterone, cortisol, and thyroxine). They found that basal testosterone levels were positively correlated with aggressive behaviours.

The Reciprocal model of testosterone

The Reciprocal model of testosterone suggests the opposite of the Basal model. According to it, testosterone is determined by a person’s standing in their social hierarchy, which determines their dominance levels. Testosterone varies in this model in accordance with a person’s ranking.

Mazur and Michalek (1998)

In this study, male air force veterans who were going through a divorce had higher levels of testosterone compared with those who were currently married. This suggested that testosterone levels are not constant. They vary depending on a person’s social standing and context.

Testosterone Research Hierarchy Reciprocal Model of Testosterone StudySmarterSocial hierarchy, flaticon.com.

Evaluation of research on testosterone’s effects on aggression

Considering the above, it’s important to evaluate the studies and research surrounding testosterone and its association with aggression.

Kreuz and Rose (1972)

In this study, they measured the testosterone levels of 21 young male prisoners who had a history of aggressive behaviour, and who had displayed aggression whilst in prison.

Researchers found that those who had committed violent crimes or had a history of aggressive behaviours had higher levels of testosterone compared to those who didn’t have this history. This suggests that higher levels of testosterone are related to aggressive or violent behaviours.

The sample size for this study was low, which is something that we need to keep in mind.

Dabbs et al. (1987)

In this study, they measured the testosterone levels in the saliva of 89 prisoners.

Researchers found that 9 out of 11 inmates with low testosterone levels had committed nonviolent crimes in their past compared to 10 out of 11 inmates with high testosterone levels, who had committed violent crimes in their past.

This suggests again that high levels of testosterone are linked to more aggressive or violent behaviours, even when associated with crime.

This study, as well as Kreuz and Rose’s, has a relatively low sample size and is quite specific as it focuses on prisoners. This makes it hard to apply the results to the general population.

Mazur (1985)

In his analysis of aggression and dominance, Mazur found that high testosterone levels are directly related to dominance behaviours, specifically, aggressive behaviours. Criminals and those involved in military professions who had high levels of aggression were found to also have high levels of testosterone.

However, this does not mean high levels of testosterone result in aggression every time. Mediating factors, such as social contexts and the individual levels of control, especially when we consider serotonin and cortisol, affect how these aggressive behaviours manifest.

Mazur suggested that there isn’t a completely causal relationship, either. Testosterone is associated with aggressive behaviours, but we can’t say that it’s the direct and only cause.

Wagner et al. (1979)

In this study, Wagner et al. analysed the effects of varying hormone levels on biting behaviors (aggressive behaviours) in mice. They referred to these as bite-attack levels.

Castration affected hormones in male mice and the bite-attack levels lowered upon castration. However, these mice showed an increase in bite-attack levels after being injected with testosterone to regain normal hormonal levels.

This shows that testosterone is important in the expression of aggressive behaviours in male mice and is critical for bite-attack behaviours. Some suggest this study is a good model for studying pharmacological and physiological effects on aggressive behaviours.

Motta et al. (2018)

Motta et al. found that those who take suppressants to reduce testosterone (for example if they were transitioning from male to female) were less aggressive, and those taking more testosterone were more aggressive.

In some athletes, testosterone levels would supposedly be at an all-time high, perhaps all of the time, as usually testosterone levels are associated with muscle growth.

Testosterone boosters or supplements are seen as performance enhancers. In recent news, for example, some women with naturally high testosterone have had trouble competing in sports because of this.

However, this isn’t always the case. Sönksen et al. (2018) tested elite athletes in the Olympics for various chemical levels in their bodies. This included testosterone. They found lower testosterone levels in 25.4% of male elite competitors in 12 of the 15 sports analysed. They also found high testosterone levels in 4.8% of female elite athletes in 3 of the 8 sports analysed.

These results suggest that the body differences developed may not be a result of the hormones beforehand and that androgynous traits (high testosterone in women, for instance) may either be a result or a cause of these differing levels.

Thus, while testosterone may facilitate muscle growth and competitiveness, a lack of testosterone or lower levels doesn’t mean that individuals can’t perform well.

Testosterone Research - Key takeaways

  • Testosterone is an androgen (male hormone) and an anabolic steroid. It aids in the development of secondary male characteristics such as hair growth on the face and body, muscle and skeletal development, and sexual and reproductive health.
  • It is said to be one of the main driving forces behind aggressive behaviours such as anger, verbal aggressiveness, and dominance.
  • The basal model suggests aggression is a stable trait and can predict aggressive behaviours. The reciprocal model suggests the opposite and that it is determined by social ranking and dominance levels.
  • Multiple studies show criminals with violent pasts had higher levels of testosterone, whilst criminals with nonviolent pasts had lower levels of testosterone.
  • Dominance is related to testosterone in mice, and those who were taking supplements to increase testosterone levels tended to display more aggressive behaviours. The opposite is also true.

Frequently Asked Questions about Testosterone Research

Testosterone is a hormone produced by the gonads and the adrenal gland that plays a role in the development of male characteristics. As established in this article, it also is associated with certain behaviours, such as aggression, dominance, competitiveness, and self-control/confidence. 

Yes, especially for males during puberty. It’s important in healthy development in males, and somewhat in females. In men, it is associated heavily with regulating sex drive, bone mass and fat distribution, muscle mass and other sexual health-related functions.

As testosterone affects the amygdala by enhancing its emotional reactivity and reducing its inhibition by the prefrontal cortex, it affects emotional behaviours. This can translate to an effect on mental health. Low levels have been associated with depression, irritability, and other mental health-related issues. 


StudySmarter is not a licensed medical practitioner. This information is for educational purposes only.

If levels are too high or too low, yes, it can affect your personality. If you have high levels of testosterone, research suggests you will show more dominant, aggressive behaviours. Low levels may produce the opposite.

Testosterone levels can facilitate feelings of anger, yes. However, it is not the direct cause of anger.

Final Testosterone Research Quiz

Question

What is testosterone?

Show answer

Answer

It is an androgen and an anabolic steroid. It is a hormone.

Show question

Question

Where is testosterone produced?

Show answer

Answer

In the gonads and the adrenal cortex.

Show question

Question

What does testosterone enable?


Show answer

Answer

Testosterone enables the development of male characteristics, and secondary ‘male’ characteristics such as muscle and skeletal growth, as well as body hair and facial hair.

Show question

Question

What happens if testosterone levels are low during puberty in men?

Show answer

Answer

When there is not enough testosterone in the body, especially for males undergoing puberty, the development of male characteristics is affected, such as hair growth on the body and face, as well as affecting healthy sexual development.

Show question

Question

What are examples of aggressive behaviours?


Show answer

Answer

Anger, verbal aggression, dominance, competitiveness.

Show question

Question

How does testosterone affect the amygdala?


Show answer

Answer

Testosterone activates the amygdala, enhancing its resistance to regulation from the prefrontal cortex (PFC), and increasing its emotional reaction to stimuli.

Show question

Question

What helps mediate testosterone and the amygdala/frontal cortexes?


Show answer

Answer

Cortisol and serotonin.

Show question

Question

What is the Basal Model?

Show answer

Answer

The Basal Model of testosterone suggests that testosterone changes a person’s level of dominance.

Show question

Question

What is the Reciprocal Model?


Show answer

Answer

Testosterone is determined by a person’s standing in their social hierarchy, which determines their dominance levels.

Show question

Question

What did Kreuz and Rose (1972) find in their study?

Show answer

Answer

They measured testosterone levels in prisoners. Those who had committed violent crimes or had a history of aggressive behaviours had higher levels of testosterone compared to those who didn’t have this history.

Show question

Question

What did Dabbs et al. (1987) find in their study?


Show answer

Answer

They measured the testosterone levels in the saliva of 89 prisoners: 9 out of 11 inmates with low testosterone levels had committed nonviolent crimes in their past, whereas 10 out of 11 inmates with high testosterone levels had committed violent crimes in their past.

Show question

Question

What does Mazur (1985) say about testosterone and dominance?


Show answer

Answer

High levels of testosterone are positively correlated with levels of dominance.

Show question

Question

In those who are transitioning, what does an increase in testosterone cause when they take supplements?


Show answer

Answer

Increased levels of anger/aggression.

Show question

Question

What did Mazur and Michalek (1998) find in their study?

Show answer

Answer

Men who were going through a divorce had higher testosterone levels than those who were still married.

Show question

60%

of the users don't pass the Testosterone Research quiz! Will you pass the quiz?

Start Quiz

Discover the right content for your subjects

No need to cheat if you have everything you need to succeed! Packed into one app!

Study Plan

Be perfectly prepared on time with an individual plan.

Quizzes

Test your knowledge with gamified quizzes.

Flashcards

Create and find flashcards in record time.

Notes

Create beautiful notes faster than ever before.

Study Sets

Have all your study materials in one place.

Documents

Upload unlimited documents and save them online.

Study Analytics

Identify your study strength and weaknesses.

Weekly Goals

Set individual study goals and earn points reaching them.

Smart Reminders

Stop procrastinating with our study reminders.

Rewards

Earn points, unlock badges and level up while studying.

Magic Marker

Create flashcards in notes completely automatically.

Smart Formatting

Create the most beautiful study materials using our templates.

Sign up to highlight and take notes. It’s 100% free.