Motivation and emotion/Book/2023/Testosterone and violent crime

Testosterone and violent crime:
What is the relationship between testosterone and violent crime?

Multimedia presentation (3 min)

Overview

Scenario: Imagine you are called in for jury duty. There are 3 cases which required your attention. The first a aggravated assault case, the second an armed robbery case and the final case, rape. Sat in the holding cell are three perpetrators. The first, a large, muscular man, with a stubble beard, the second an average, normal looking male, and finally, another average looking male with what appear to be a very bushy beard. Its is apparent that these man all are here on any of the 3 cases presented to you that day. You are sat there unsure which man was suspected of committing any of these crimes, it could have been any one of them for any of the three cases. One thing become apparent to you whilst sitting in the courtroom, that all 3 cases are that of violent crime. You think, violent? Only one of the 3 males in the courtroom looks like he could have committed all 3 of the crimes, but then again these are 3 separate cases. You begin to think if only one male looks like he can commit all 3 of these crimes, what makes the other 2 males similar to the first?

Figure 1. Image illustrating violence

,

Testosterone is commonly known as the male reproductive hormone. It is also know that testosterone help in increasing muscle mass, bone density and sex drive, however is is also known for aggressive behaviours. Crime are present in everyday life, where it can be viewed as opposing the law and order that uphold our society, a constant tango between good and bad, yin and yang. *** Violent crimes are one of the many crimes that can be committed which appose law and order. These crimes are constitute murder, robbery, assault and rape. Criminals that commit such unlawful acts do so on their own motives which they choose to act upon. Such motives include intrinsic motive such as revenge or seeking of the "thrill" of commit these unlawful act, extrinsic motivation where criminals commit these acts for external rewards, and finally dominance over their victims. Although some motivation can be due to personality disorders such as borderline personality disorder and antisocial personality disorder. Investigation of inmate testosterone indicates that such crimes are committed by criminals with high levels of testosterone in the bodies. As mentioned before testosterone has been liked to aggression, could it also be indicative of violent crime?

Focus questions: How does testosterone affect brain structures? How does testosterone affect aggression? How does aggression correlate with violent crime?

Testosterone

Testosterone is a human hormone produced in the gonads. In males’ production of testosterone is done by Leydig cells in the testes and by the ovaries in women (Nassar & Leslie, 2023). Although testosterone is commonly viewed as the male hormone it is still present in females. Testosterone plays a role in the development of the male reproductive tissues in early development and has further characteristics in muscle and bone mass, growth of body hair, effects on sex drives (Anthony, 2017). Males with low testosterone levels may experience weight gain, worst moods and mental health, lower muscles and bone mass and less body hair. Low testosterone levels can be due to a hyposecretion of testosterone in the testes, tremors caused to the testes or old age (E. Charles Osterberg et al., 2014). For female’s testosterone is used in combination with oestrogen the female sex hormone, for growth, maintenance and repair of female reproductive tissue and bone mass. However, it is not uncommon for females to also experience high levels of testosterone, which may have characteristic features such as, deepening of the voice, excess body hair, increased muscle mass and decreased breast size (Anthony, 2017)

Testosterone replacement therapy and testosterone abuse

Testosterone replacement therapy is a commonly used treatment for men with hypogonadism. As testosterone declines due to age or because of other reasons such as tremors or hyposecretion testosterone replacement therapy may become a desirable treatment for males with lowered Testosterone levels (E. Charles Osterberg et al., 2014). Testosterone replacement therapy can be administered via tablets taken orally, through intramuscular injections, transdermal patches and using creams and gels. The Therapy is meant to increase the levels of testosterone to allow males to increase muscle mass and bone density and increase libido. (Jockenhovel, 2023) Anabolic steroid are manufactured drugs which imitate testosterone. These drugs are classified as a class C drug and are frowned upon in competitive sports. Such drugs are used as performance enhancing tools that help increase muscle mass, decrease fat, build the body to improve physical performance (Kuhn, 2002, Ganesan et al., 2016). People with body dysmorphic disorders may take these drugs to achieve what they perceive to be their ideal body (Vashi, 2016). However, abuse of these drugs has serious and dangerous side affects for both males and female that use anabolic steroids. such health risks include, heart attacks and strokes, liver and kidney failure, hypertension, fluid retention and high cholesterol. Furthermore, abuse of these drugs can have negative psychological affects too such as aggressive behavior, paranoia, manic behavior, and delusions (NHS Choices, 2023)

What constitutes violent crime?

Figure 2. Painting of a knight killing a priest.

Murder

Murder is defined as taking someone else's life without justification or a valid excuse. While it might have been considered justifiable in past cultures, today, it is universally regarded as an unlawful act in society. Murder is classified into three categories or degrees. First-degree murder is defined as the unlawful killing of another human being with intent, deliberation, premeditation, and malice aforethought. "Intent" refers to the perpetrator's conscious intention to end another person's life. "Deliberation" and "premeditation" mean that the perpetrator has planned and considered ending another individual's life beforehand, rather than acting impulsively. "Malice aforethought" is a legal term indicating that the perpetrator committed the act with a disregard for human life. Second-degree murder is a lesser degree than first-degree murder. It is described as the unlawful killing of another individual without premeditation, meaning that the perpetrator acted without prior planning. Murder in the third degree involves understanding the dangerous behavioural risks that can cause the death of others but acting anyway, resulting in the death of another individual. For example, ending another person's life while driving under the influence may lead to a charge of third-degree murder, as the perpetrator understood the risks but still engaged in the behaviour that resulted in someone's death.

Forcible Rape

Violent crimes also include unlawful sexual acts, with rape being one of them. Rape is the unlawful act of sexual intercourse without consent, regardless of the gender of the victim. Although rape is more commonly committed against females, cases of male victims also exist, albeit less frequently. Forcible rape involves the act of forcibly committing sexual acts against another person's will. The perpetrator may attempt to commit rape using force or threats to cause harm or injury to the victim. This is known as first-degree rape. Second-degree rape still involves forcible rape, but the victim is either physically helpless or mentally incapacitated. Additionally, rape can occur when individuals in positions of power take advantage of those under their care, such as caregivers or healthcare workers. Third-degree rape refers to committing sexual acts with another person without clear and expressed consent and with threats to harm the victim's property. Statutory rape is another category and involves unforced intercourse between an adult and a child or teenager, where the minor may not be legally capable of giving appropriate consent. It's important to note that laws related to statutory rape may vary across states and countries due to differences in the age of consent.

Robbery

Figure 3. Newspaper image of a man assaulting another man.

Robbery is defined as the theft from a person accomplished through the use of force, intimidation, or threats either before, during, or after the theft. Robbery is considered a composite offense, combining elements of both violent crimes and property offenses. It's important to distinguish between robbery and theft, as theft is a property offense conducted without the aspect of violence. Types of theft include burglary, shoplifting, pickpocketing, and grand theft auto. Aggravated robbery is a more serious offense than basic robbery. It occurs when the crime of robbery is committed in the company of more than one person and with the use of a weapon. A prime example of aggravated robbery could be a home invasion, where perpetrators enter a victim's home with the intent to steal property while the occupants are present, often using threats, fear, and intimidation to achieve their goals. Robbery can lead to aggravated assault and possibly second-degree murder if the perpetrator encounters resistance from the victim.

Aggravated Assault

Aggravated assault involves the intentional harming of another human being. This harm can be done with or without intent and premeditation, but unlike murder, aggravated assault does not result in the death of the victim. Aggravated assault can be committed with or without a weapon. Assault without a weapon involves the perpetrator intending to cause harm to another individual by using parts of their own body, such as fists, elbows, knees, and feet. Assault with a weapon is a more serious crime and encompasses harming another individual with non-lethal objects, such as chairs, tables, bottles, or shoes. It's important to note that although these objects are considered "non-lethal," they can still cause significant harm to another person. Assault with a lethal weapon occurs when the perpetrator intends to cause harm using objects that have the potential to end another person's life, such as knives, garden tools, axes, or bricks. Assault with a lethal weapon can easily escalate to second-degree murder if the perpetrator's assault results in the victim's death, making it the most serious charge related to aggravated assault

Theoretical underpins of violent crime

Intrinsic motivation

Intrinsic motivation is the act of doing something for the inherit satisfaction rather than an external reward (Reiss, 2016). For criminals that commit violent crimes they might be intrinsically motivated by revenge, an act of hurting or harming someone in return for their wrongdoing towards you or someone you know (Schumann & Ross, 2010), or for the “Thrill” of the crime. Some criminals maybe find excitement or a desire to commit these crimes as they begin to find them enjoyable. This could be linked to personality or mental illness, such as antisocial personality disorder, psychopathy, and borderline personality disorder, the thrill for committing violent crimes intrinsically motivates criminals to commit such crimes. Violent crimes such as murder, rape and aggravated assault are most likely to be intrinsically motivated as in committing such acts provide no external reward for the perpetrator.

Figure 4. Maslow's hierarchy of needs

Extrinsic motivation

Extrinsic motivation is the act of doing something for an external reward (Reiss, 2016). Criminals would be extrinsically motivated to commit violent crimes if in return the criminal gets something in return. For example, a perpetrator maybe motivated to commit and aggravated robbery to obtain money that could be used to fuel a gambling or drug addiction. The external reward here is the money that is used to gain internal satisfaction (drug or gambling addition). Robbery is most likely out of the violent crimes to be extrinsically motivated as for the criminal there is a reward. Murder, aggravated assault, and rape don’t reward the criminal externally.

Maslow's Hierarchy of needs

Abraham Maslow first proposed the hierarchy of needs in his paper, “A Theory of Human Motivation” (Maslow, 1943). Since then, the theory commonly known as Maslow’s hierarchy of needs has been broadly studied. The model Maslow proposed is quite simple, it consists of a pyramid with five stages (Figure 4). To reach the top of Maslow’s pyramid of needs you need to first have all the needs below it stratified. At every base of the pyramid is physiological needs (food water, shelter, sleep), then the next stage up is safety needs (employment, resources, health), further up on the nest stage is, love and belonging (friendships, family, sense of connection), further up on the next stage, esteem (respect, status, recognition) and finally at the very top self-actualization (becoming the most some can be). For criminals they may be motivated to commit violent crimes to achieve some aspect of any of the 5 stages in the hierarchy of needs. For example, to fulfil their physiological needs criminals may commit acts of robbery to afford food and clothing.

Power Motivation

Power motivation is the desire to have an impact on other people’s behaviour and emotions (Winter, 1992). Power motivated people are said to be especially concerned about their prestige, social status, and reputation; however, power motives are also significant predictors of aggressiveness, risk taking in gambling and autocratic business decisions (Wang et al., 2022). Furthermore, such power motives can be indicative of the “thrill” of murder.  One of the most common motives for murder is the perpetrator feels the need to exercise control and power over their victims, to resolve feelings of inferiority (Hickey, 2003). Furthermore, people in position of power as mentioned before, may be motivated to rape their victims to assert power over them and give them a sense of control (Yourell et al., 2014)

How is testosterone associated with violent crime?

Affects of testosterone of the amygdala

Figure 5: Where the amygdala is located on a model of the brain.

The amygdala is a subcortical brain structure that is part of the limbic system in the brain. It is located deep within the medial temporal lobe and consists of two almond-shaped clusters of nuclei. The amygdala plays a crucial role in managing information between the prefrontal-temporal cortices and the hypothalamus (Figure 5). Additionally, it is involved in the regulation of anxiety, aggression, fear conditioning, emotional memory, and social cognition (AbuHasan et al., 2023).

Testosterone may increase aggressive behaviours, as it enhances activity in the amygdala when an individual perceives a threat. Neuroimaging techniques have shown that, in adult males, testosterone activates the amygdala, promoting emotional activity and reducing the inhibitory control of the prefrontal cortex (Batrinos, 2012).

Cortisol, commonly known as the stress hormone, is synthesized from cholesterol in the zona fasciculata layer of the adrenal cortex (Thau et al., 2022). In the brain, cortisol acts as an antagonist to testosterone, as high levels of cortisol are often associated with submissive behaviours, whereas high levels of testosterone are linked to aggressive behaviours. Therefore, a high testosterone-to-cortisol ratio is more likely to result in aggressive behaviour, thus a high cortisol-to-testosterone levels would result in submissive behaviours (Batrinos, 2012). Therefore, high levels of hormones such as testosterone influence brain structures like the amygdala, causing hyperactivity in the structure and leading to aggressive behaviours, while cortisol, another hormone, activates the amygdala in the opposite manner.

Aggression

Figure 6: Drawing depicting aggressive behaviour.

Aggression is a feeling of anger that often results in physical or emotional harm to another human or leads to property damage or destruction. Although aggression is commonly associated with a violent nature, not all aggression is based on violence but rather on using strategic force to achieve a goal. Combat and contact sports, such as mixed martial arts and rugby, utilize one of the four types of aggression: instrumental aggression, where aggression is used to achieve a goal like defeating your opponent or making a tackle to regain possession of the ball. In sports, instrumental aggression is employed in a controlled manner to prevent harm to athletes. Accidental aggression occurs as a result of an accident, without intent, such as accidentally bumping into someone, knocking them over, or breaking a glass at dinner because it was misplaced on the table. Hostile aggression is used with the purpose of intentionally harming another individual physically or psychologically. Expressive aggression involves committing acts of aggression because it provides a sense of satisfaction (Kostelnik et al., 2010). Hostile and expressive forms of aggression are most likely to be observed in violent crimes such as murder, aggravated assault, rape, and robbery, as they are motivated by the "thrill" of aggression.

Aggression and violent crime

How aggression influences motives of violent crimes

Aggression may serve as a motivating factor for violence, as it is often associated with causing harm to others. For individuals who commit violent crimes, aggression plays a crucial role in motivating their actions. According to the Power Motivation and Dominance Theory, people have a desire to exert influence over others' behaviour and emotions (Winter, 1992), and aggression is a significant predictor of such motives. This phenomenon is closely tied to the concept of the "culture of honour. “The culture of honour encompasses a set of beliefs, attitudes, and norms related to personal reputation and the imperative to protect and defend one's reputation and social image. Social and environmental factors also contribute to the development of the culture of honour. Exposure to violence at home and association with peers engaged in criminal activities can be predictors of the culture of honour, leading to increased aggressive behaviours (Lansford, 2018).

In addition to general aggression, instrumental aggression is often used in violent crimes to achieve specific goals or exert control over others, as seen in cases of robbery, assault, and rape. Instrumental aggression can be linked to various motivational theories, including intrinsic motivation, extrinsic motivation, and Maslow's Hierarchy of Needs. Furthermore, the use of hostile aggression can be a predictor of intrinsic motivation in violent crimes. Criminals seeking the "thrill" or internal satisfaction through committing violent crimes employ hostile aggression to satisfy their intrinsic motivation.

Figure 7: Image of an inmate behind bars.

How aggression influences psychological factors

Aggression is often associated with intense emotional states, such as anger, fear, or frustration, as well as psychopathological factors. Disorders like antisocial personality disorder and conduct disorder are linked to higher levels of aggression and an increased risk of committing violent crimes (Stålenheim et al., 1998; Räsänen et al., 2007). This could be attributed to a lack of impulse control. Impulse control is characterized by urges and behaviours that can be excessive and harmful to oneself or others (Schreiber et al., 2011). Individuals who lack impulse control may act on aggressive urges without considering the consequences, potentially leading them to commit violent crimes (Carmen et al., 2016). It's worth noting that while impulse control is often comorbid with psychological disorders, it can also occur in individuals without such disorders. Emotional factors may serve as predictors of a lack of impulse control, as heightened levels of negative emotions can escalate and result in outbursts or impulsive behaviours, ultimately contributing to the commission of violent crimes (Carmen et al., 2016).

Testosterone and incarceration

Many studies have been conducted in studying the levels of testosterone of prison inmates. One study conducted by Dabbs and colleagues (1995) finds that inmates who had committed violent and sexual crimes had higher levels of testosterone than inmates who committed property crimes such as burglary, theft, and drug crimes. Furthermore, to these findings Dabbs and colleagues go on to say that inmates with higher testosterone levels were more likely to violate rules in prisons. These findings indicate that inmates who committed violent crimes such as murder, rape, assault, and robbery where more likely to be higher in testosterone levels than those inmates that didn’t commit violent crimes.

Conclusion

There seems to be no direct association between violent crime and testosterone. However, testosterone is positively associated with aggressive behaviour, which is an influencing factor in committing violent crimes. High levels of testosterone don’t indicate violent crimes as it can be found in athletes and normal people who do not and are not motivated to commit violent crimes. For those individuals that do choose to commit these violent crimes, high levels of testosterone may be an influencing factor in their aggressive behaviours but does not directly motivated people to commit violent crimes. Such motives could be intrinsic, extrinsic based of their perceived needs or want for power and control over their victims, all of which are not directly influence by testosterone. Thus testosterone may be associated with aggressive behaviour but it doesn’t directly motivate violent crimes.

Quiz 1 The amygdala is involved in the regulation of:: memory, emotional intelligence, social cognition. anxiety, aggression, fear conditioning and emotional memory. joy, anger, sadness and empathy. anxiety, depression, social cognition. 2 Male with low levels of testosterone may experience: Less body hair, increase muscle mass, decrease mental health. Weight gain, lower muscle tone, increase bone density. Muscle loss, less body hair, better temperament. Weight gain, worst moods and mental health, lower muscles and bone mass. 3 What are the five levels of Maslow's hierarchy of needs?: Self actualisation, esteem, love/belonging, safety, physiological and emotional intelligence. Self actualisation, love/belonging, safety, emotion and motivation. Social cognition, self actualisation, esteem, love/belonging and safety. Self actualisation, esteem, love/belonging, safety and physiological.

See also

• Violent crime motivation (Book chapter, 2010)
• Domestic violence motivation (Book chapter, 2020)
• Testosterone and emotion (Book chapter, 2014)
• Testosterone and sexual motivation (Book chapter, 2017)
• Aggression (Book chapter, 2011)
• Neurobiology of aggression (Book chapter, 2010)

References

AbuHasan, Q., Reddy, V., & Siddiqui, W. (2023, July 17). Neuroanatomy, Amygdala. Nih.gov; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK537102/#:~:text=The%20amygdala%20is%20an%20almond,extensive%20internuclear%20and%20intranuclear%20connections.

Anthony, K. (2017, October 13). High Testosterone Levels in Women. Healthline; Healthline Media. https://www.healthline.com/health/high-testosterone-in-women#-Women-with-high-testosterone

Armstrong, T. A., Boisvert, D., Wells, J., Lewis, R. H., Cooke, E. M., Woeckener, M., Kavish, N., Vietto, N., & Harper, J. M. (2022). Testosterone, cortisol, and criminal behavior in men and women. Hormones and Behavior, 146, 105260–105260. https://doi.org/10.1016/j.yhbeh.2022.105260

Batrinos, M. L. (2012). Testosterone and aggressive behavior in man. International Journal of Endocrinology and Metabolism, 10(3), 563–568. https://doi.org/10.5812/ijem.3661

Carmen, del, Mar, del, Carrión, J., Isabel Mercader Rubio, & Gázquez, J. J. (2016). Sensation-Seeking and Impulsivity as Predictors of Reactive and Proactive Aggression in Adolescents. Frontiers in Psychology, 7. https://doi.org/10.3389/fpsyg.2016.01447

Dabbs, J. M., Carr, T. S., Frady, R. L., & Riad, J. K. (1995). Testosterone, crime, and misbehavior among 692 male prison inmates. Personality and Individual Differences, 18(5), 627–633. https://doi.org/10.1016/0191-8869(94)00177-t

E. Charles Osterberg, Bernie, A., & Ramasamy, R. (2014). Risks of testosterone replacement therapy in men. Indian Journal of Urology, 30(1), 2–2. https://doi.org/10.4103/0970-1591.124197

Ganesan, K., Rahman, S., & Zito, P. (2016). Europe PMC. Europepmc.org. https://europepmc.org/article/NBK/nbk482418

Giammanco, M., Tabacchi, G., Giammanco, S., Majo, D., & Guardia, L. (2005). P E R S O N A L U S E O N L Y Testosterone and aggressiveness Word count. https://hormonebalance.org/images/documents/Testosterone%20and%20aggressiveness.pdf

Hickey, E. W. (2003). Encyclopedia of Murder and Violent Crime. In SAGE Publications, Inc. eBooks. https://doi.org/10.4135/9781412950619

Jockenhovel, F. (2023). Testosterone therapy - what, when and to whom? The Aging Male. https://www.tandfonline.com/doi/abs/10.1080/13685530400016557

Kostelnik, M., Purcell, S., Schroeder, D., Nelson, M., Krumbach, E., Effken, Hanna, J., Durden, T., Renee, Defrain, J., & Bosch, K. (2010). Helping Children Resolve Conflict: Aggressive Behavior of Children .G2016 (p. 72). https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1072&context=cyfsfacpub#:~:text=Aggression%20is%20any%20behavior%20that

Kuhn, C. (2002). Anabolic Steroids. https://www.endocrine.org/~/media/endosociety/Files/EP/RPHR/57/RPHR_vol_57_ch_19_anabolic_steroids.pdf

Lansford, J. E. (2018). Development of aggression. Current Opinion in Psychology, 19, 17–21. https://doi.org/10.1016/j.copsyc.2017.03.015

Maslow, A.H. (1943). “A Theory of Human Motivation”. In Psychological Review, 50 (4), 430-437. Washington, DC: American Psychological Association.

Nassar, G. N., & Leslie, S. W. (2023, January 2). Physiology, Testosterone. Nih.gov; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK526128/#:~:text=Testosterone%20is%20the%20primary%20male,males%20and%20females%20are%20identical.

Räsänen, P., Helinä Hakko, S. Visuri, Jarmo Paanila, P. Kapanen, Suomela, T., & Jari Tiihonen. (2007). Serum testosterone levels, mental disorders and criminal behaviour. Acta Psychiatrica Scandinavica, 99(5), 348–352. https://doi.org/10.1111/j.1600-0447.1999.tb07240.x

Reiss, S. (2016). Intrinsic and Extrinsic Motivation - Steven Reiss, 2012. Teaching of Psychology. https://journals.sagepub.com/doi/full/10.1177/0098628312437704?casa_token=vFN7BmAXQGsAAAAA%3ArXsilVm77yE_gGZsggrN3SGiwnqMkG1XGTeXl18lYuQDeS_w3bHc6SuOLWESWtKyhYCYdUaheBQE2Q

Rowe, R., Maughan, B., Worthman, C. M., E. Jane Costello, & Angold, A. (2004). Testosterone, antisocial behavior, and social dominance in boys: pubertal development and biosocial interaction. Biological Psychiatry, 55(5), 546–552. https://doi.org/10.1016/j.biopsych.2003.10.010

Schreiber, L., Odlaug, B. L., & Grant, J. E. (2011a). Impulse Control Disorders: Updated Review of Clinical Characteristics and Pharmacological Management. Frontiers in Psychiatry, 2. https://doi.org/10.3389/fpsyt.2011.00001

Schreiber, L., Odlaug, B. L., & Grant, J. E. (2011b). Impulse Control Disorders: Updated Review of Clinical Characteristics and Pharmacological Management. Frontiers in Psychiatry, 2. https://doi.org/10.3389/fpsyt.2011.00001

Schumann, K., & Ross, M. (2010). The Benefits, Costs, and Paradox of Revenge. Social and Personality Psychology Compass, 4(12), 1193–1205. https://doi.org/10.1111/j.1751-9004.2010.00322.x

stålenheim, E. Gunilla., Eriksson, E., Lars von Knorring, & Wide, L. (1998). Testosterone as a biological marker in psychopathy and alcoholism. Psychiatry Research, 77(2), 79–88. https://doi.org/10.1016/s0165-1781(97)00143-1

Thau, L., Gandhi, J., & Sharma, S. (2022, August 29). Physiology, Cortisol. Nih.gov; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK538239/

Vashi, N. A. (2016a). Obsession with perfection: Body dysmorphia. Clinics in Dermatology, 34(6), 788–791. https://doi.org/10.1016/j.clindermatol.2016.04.006

Vashi, N. A. (2016b). Obsession with perfection: Body dysmorphia. Clinics in Dermatology, 34(6), 788–791. https://doi.org/10.1016/j.clindermatol.2016.04.006

Wang, J., Qu, S., Li, R., & Fu, Y. (2022). Power motivation arousal promotes prosocial behavior in the dictator game depending on social presence. PLOS ONE, 17(11), e0277294–e0277294. https://doi.org/10.1371/journal.pone.0277294

Winter, D. G. (1992). Power motivation revisited. Cambridge University Press EBooks, 301–310. https://doi.org/10.1017/cbo9780511527937.022

Yourell, A. M., A, B., & McCabe, M. P. (2014). The Motivations Underlying Male Rape of Women.: Australian Journal of Sex, Marriage and Family: Vol 9, No 4. Australian Journal of Sex, Marriage and Family. https://www.tandfonline.com/doi/epdf/10.1080/00021369.1988.11005977?needAccess=true

External links

• Maslow's Hierarchy of Needs (YouTube video)
• Intrinsic and extrinsic motivation (YouTube Video)
• The puzzle of motivation (TED Talk)
• Antisocial Personality Disorder (APA article)
• Trend in violent crime (Australian Government)
• Testosterone Therapy (YouTube Video)