Motivation and emotion/Book/2014/Testosterone and emotion

Overview
Patrick is an aspiring fitness model who lives a healthy lifestyle and works as a personal trainer at his local gym. From observing his clients, he has noticed that young males display aggressive behaviour while working out, while older men are often weaker and occasionally seem depressed. He often finds himself trying his absolute best to keep the older men focused on their workout as they often feel like giving up. However, he has some other clients who are significantly old yet work out with the same aggression as the younger men do. Patrick suspects that testosterone may have a relation to the emotions he observes in his clients.

This chapter informs readers about the effects of testosterone on emotion. It investigates testosterone, what it is, and theoretical approaches. The chapter's primary focus is to inform the reader of how testosterone relates to aggression, depression and mood.


 * Learning objectives
 * 1) What is testosterone?
 * 2) What is the challenge hypothesis?
 * 3) What information exists about the relationship between testosterone and aggression, depression and mood?
 * 4) To be able to apply psychological knowledge regarding testosterone and emotion to one's life

What is testosterone?
Hailing from the androgenic family of hormones, testosterone is a steroidal hormone which is present in both men and women (Terburg, Morgan & Van Honk, 2009; Johnson, Nachtigall & Stern, 2013). In men, the predominant purpose of testosterone is for sexual health and maintaining masculine characteristics (Terburg et al., 2009; Johnson et al., 2013). Testosterone is an important factor in the growth of both muscle and bone mass as well as the growth of the male reproductive organs (Terburg et al., 2009; Johnson et al., 2013), and is primarily found in the testicles and adrenal glands (Johnson et al., 2013). In women, testosterone exists in much smaller quantities compared to men (Johnson et al., 2013), and is primarily located in the adrenal glands and ovaries (Johnson et al., 2013). Men are known to have up to 7 times more testosterone than women (Johnson et al., 2013), with the average level of testosterone ranging between 300 and 1000ng/dl (nanograms/decilitre) (Johnson et al., 2013). In research applications, testosterone is primarily measured by the total serum quantity (Johnson et al., 2013). In men, it is noted that testosterone levels decline at a stable rate throughout the lifespan with its highest point occurring during puberty and late adolescence (Johnson et al., 2013). For females, testosterone dramatically declines following menopause when oestrogen production is reduced (Johnson et al., 2013; Rohr, 2002).

Hypogonadism
Men with low testosterone levels have an increased chance in experiencing mild anaemia, loss of muscle mass, decrease in physical strength, increase in body fat, as well as a decline in physical and work performance (Johnson et al., 2013; Wang et al., 2008). Depressive mood, constant fatigue and poor concentration are also consequences a male may experience as the result of having low testosterone (Johnson et al., 2013; Wang et al., 2008). Further problems regarding low testosterone include sexual health complications and in extreme cases, it can be linked to hypogonadism (Johnson et al., 2013; Wang et al., 2008). Hypogonadism is a significant issue concerning men’s health as it is a threat to the sexual functioning of males and is highly correlated with low testosterone levels (Wang et al., 2008). If a male has 1 or more of the direct symptoms (low libido, erectile dysfunction or osteoporosis) and 2 or more of the indirect symptoms (sleep disturbance, depressed mood, lethargy or poor physical performance) as well as testosterone measured to be below 300ng/dl, they are diagnosed by clinicians as having hypogonadism (Wang et al., 2008).

The Challenge Hypothesis
A general theory about how testosterone affects emotion does not exist thus far in the social science arena. There are explanations and perspectives on the biological and physiological aspect of testosterone. The closest application of theory on testosterone and emotions is the challenge hypothesis which has the prime focus of explaining testosterones relationship with aggression. The challenge hypothesis was originally conceptualised to explain how testosterone fuelled acts of aggression occur in monogamous mating birds (Wingfield, Hegner, Dufty & Ball, 1990). Then, Archer (2006) attempted to apply the same theoretical constructs with a hypothetical stance on humans and aggression. There are 6 hypotheticals proposed (Archer, 2006):

“Hypothesis 1: There is no increase in aggression at puberty” (Archer, 2006, p.322).

The initial application of the challenge hypothesis on birds, established two specific testosterone-driven relationships which included the support of courtship and matting during the breeding season. The second was to engage in competitive behaviour when given the opportunity to do so by reproductive competition (Wingfield, Hegner, Dufty & Ball, 1990). Therefore, even though there is an increase of sexual interest that is caused by testosterone during puberty, it is expected that there will be no testosterone-related increases in aggression during puberty of human males (Archer, 2006).

“Hypothesis 2A: Men respond to sexual arousal with increased testosterone” (Archer, 2006, p.323).

The original theoretical application of testosterone in birds acknowledges that testosterone is increased in birds when they are exposed to situations involving mating efforts (Wingfield, Hegner, Dufty & Ball, 1990). There is a significant amount of research which suggests that the testosterone levels of young men increase in response to situations of sexual arousal (Archer, 2006). Therefore it is put forth that there is an increase of testosterone secretion in males when they are sexually stimulated (Archer, 2006).

“Hypothesis 2B: Men respond to competition with increased testosterone” (Archer, 2006, p.324).

It is predicted that testosterone will rise in young men who are in direct competition against one another in the pursuit to receive attention from an attractive female (Archer, 2006). There has been evidence that testosterone has been increased in males who have been in situations that have required physical activity, especially when individuals respond to insults and resort to physical violence as a means to defend their honour, pride, possessions, their woman or their family (Archer, 2006). Therefore, it is predicted that men will respond to competition with increased testosterone.

“Hypothesis 3: The testosterone response to challenge increases aggression” (Archer, 2006, p.329).

The increase of aggression is expected as a result of the testosterone response to challenges (Archer, 2006). This prediction is applicable in situations which may involve competitive scenarios of violence. For example, two fighters will pursue aggressive behaviour in combat to subdue or knock their opponent out, with attack, fighting and threat being present in the scenario (Archer, 2006). However, it is acknowledged that a majority of the research that exists on aggression increasing due to the testosterone response to challenge is primarily on animals (Archer, 2006). Therefore it is difficult to examine the association of competition that is impacted by adults and their testosterone-aggression response to challenge (Archer, 2006).

“Hypothesis 4: Testosterone levels are lower among paternal men” (Archer, 2006, p.331).

There is evidence that hormonal changes occur in paternal birds of which does not occur in non-paternal birds during the time of birth (Wingfield, Hegner, Dufty & Ball, 1990). It has also been indicated that testosterone levels decline in men after the birth of their child (Archer, 2006). Hence the hypothesis that testosterone levels are lower among paternal men than non-paternal men (Archer, 2006).

“Hypothesis 5: Aggressive dominance is correlated with testosterone levels” (Archer, 2006, p.332)

It is predicted that aggression-based dominance is associated with higher testosterone levels amongst humans. The argument is that links between testosterone, aggression and dominance would reflect the snowballing effect of successful reactions to challenges (Archer, 2006).

“Hypothesis 6: Testosterone is associated with alternative life history strategies” (Archer, 2006, p.334).

The final hypothesis predicts that individual differences in testosterone levels reflect a variety of other characteristics which relate to life choices such as short term mating opportunities instead of long-term mating opportunities and paternal care (Archer, 2006). These predicted alternative life history strategies amongst humans refer to the possible choices an individual can make, which may involve pursuing short term relationships, antisocial activities and having certain personality characteristics which may incline individuals to enter different life courses (Archer, 2006).

Testosterone and aggression
There have been multiple studies in the social science arena which have explored the relationship between testosterone and aggression (Book, Starzyk & Quinsey, 2001). Studies have presented inconsistent findings (Book et al., 2001). In a meta-analysis to find the strength of the relationship between testosterone and aggression, one hundred and six articles were examined (Book et al., 2001). It was found that there was a weak, positive correlation between testosterone and aggression (Book et al., 2001). The results were universal and were not affected by sex, it was found that males have more dramatic fluctuations of testosterone throughout their lifespan than females who have lower testosterone levels which remain more stable throughout their life (Book et al., 2001). The age of the participant as well the time of day the testosterone was measured were identified as the two variables which affected the strength of the relationship between testosterone and aggression (Book et al., 2001). The male age range most common in the studies analysed was 13 to 20 years, which were suggested to be ages where testosterone is on a decline, be it prior to puberty or towards its end stage (Book et al., 2001). However, this did not affect the data regarding female testosterone levels, as age was not an issue as their testosterone levels did not fluctuate and remained at a low level regardless of age (Book et al., 2001). A majority of the studies in the meta-analysis measured participants in the morning for their testosterone levels; however, the observation between testosterone and aggression occurred in the afternoon when it is suggested to decline (Book et al., 2001).

Testosterone is a steroidal hormone which is a member of the androgen group of hormones that play a vital role in the sexual health of males as well as muscle growth, bone health and hair growth (Terburg et al., 2009; Johnson et al., 2013). Cortisol is another steroidal hormone that does the opposite of testosterone which is released when humans are in times of stress or there is a diminishing supply of blood glucose within the body (Terburg et al., 2009). The predominant function of cortisol is to control immune functions in times of stress and to increase blood sugar within the body whilst metabolising foods towards fat stores (Terburg et al., 2009). Cortisol is the body’s way to manage stress from psychological or biological stress (Terburg et al., 2009). Terburg and colleagues (2009) set out to discover the evidence between testosterone and cortisol, observing relationships towards human aggression and whether it would facilitate aggressive criminal behaviour. It is discussed that individuals with high testosterone and low cortisol are more likely to approach threat which may result in aggressive behaviour (Terburg et al., 2009). Therefore, it was predicted that high testosterone and low cortisol will facilitate aggression in social situations (Terburg et al., 2009). It was suggested that imbalances in the brain which occur from a high testosterone and low cortisol ratio result in more awareness of anger which may result in confrontations with little to no emotion other than anger or aggression (Terburg et al., 2009). Furthermore, this may motivate individuals to utilise aggressive tendencies towards stressful/threat situations and is then suggested that in an environment of normal social conduct, individuals who have this ratio will have no respect for any social hierarchy and will be more likely to utilise violence, and disregard rules to accomplish goals (Terburg et al., 2009).

Archer, Birring and Wu (1998) investigated the relationship between testosterone and aggression in young males. The empirical study examined 101 male medical students (a majority of the students were either Caucasian or Asian) who completed self report measures which aimed to assess aggressive behaviour, and also contributed blood samples which were used to measured levels of testosterone (Archer et al., 1998). The results were non significant as the testosterone levels did not show any correlations with the self reported behaviour measures on aggression and there were no differences between Caucasians or Asians within the findings (Archer et al., 1998). One justification for non significant findings were that testosterone may not be relatively high in students that have low levels of physical aggression (Archer et al., 1998). In an attempt to further investigate the implications of testosterone on aggression, a meta-analysis was conducted to observe any possible associations (Archer et al., 1998). It was hypothesised that testosterone elevates aggression in aggressive individuals. Two reviews were examined and studies which focused on students and had key words such as ‘testosterone’, ‘aggression or violence’ and ‘human’ were included in the meta-analysis. The results did not support the hypothesis, even when the testosterone levels of high and low aggression samples were selectively compared; no correlations were found (Archer et al., 1998). Therefore, it can be observed that there are bodies of research which contain little to no significance of measuring testosterone and aggression with only suggestions being put forth for future research objectives and experiments (Archer et al., 1998).

In the attempt to determine whether testosterone has a direct effect on aggression, Olweus, Mattsson, Schalling and Low (1988) examined 58 adolescent males from public schools in Sweden. Each males testosterone levels were analysed (Olweus et al., 1988). Participants were aged 15-17 years which was assessed as either being in their pubertal stage or reaching the adult stage of testosterone development (Olweus et al., 1988). A month prior to the collection of the blood samples, the participants were required to complete self-report measures which assessed aggressive traits of verbal aggression and physical aggression (Olweus et al., 1988). A physical examination was conducted on each participant to acquire variables such as pubertal stage, height, weight and chest circumference for extra data regarding the participant’s physicality (Olweus et al., 1988). A significant correlation was found between testosterone and verbal aggression as well as testosterone and physical aggression which was measured by the self report scores (Olweus et al., 1988). Further analysis suggested that there was a pattern on testosterone with verbal and physical aggression in the instances of provocation and threat or unfair treatment (Olweus et al., 1988). Therefore, it was suggested that aggressive responses to threat or being provoked were directly related to testosterone (Olweus et al., 1988). Weaker correlations were found with unprovoked physical or unprovoked verbal aggression with testosterone (Olweus et al., 1988).

Testosterone and depression
Research regarding testosterone and its affects on depression has been of focus by Booth, Johnson and Granger (1999). In the attempt to investigate testosterone and its implications for antisocial behaviour and depression, 4,393 service men who had served in Vietnam, United States, Germany and Korea between 1965 and 1971 were interviewed and physically examined (Booth et al., 1999). Depression and antisocial behaviour was assessed through interviews whilst testosterone was measured from blood samples which were collected in the morning from all participants (Booth et al., 1999). The results indicated that there was a relationship between testosterone and depression; those who had average or below average levels of testosterone had lower risk of depression (Booth et al., 1999). Whereas those who had average or above average levels of testosterone and also did not enjoy either their marriage or employment, they had greater chances of becoming depressed and were more likely to engage in antisocial behaviour (Booth et al., 1999). However, when those who had high levels of testosterone did enjoy their marriage or employment, it was found that they were less likely to be depressed (Booth et al., 1999).

Kenny, Fabregas, Song, Biskup and Bellantonio (2004) investigated older men with mild cognitive deficiencies and how testosterone would affect their functions relative to cognition, depression and behaviour (Kenny et al., 2004). A synthetic form of testosterone (Testosterone Enanthate) was provided to all participants (11 men all aged 65+) for 12 weeks which was to be intramuscularly injected (Kenny et al., 2004). It was a randomized double-blind trial where participants received either the synthetic testosterone or a placebo (Kenny et al., 2004). The aim was to discover the effect of the testosterone on the behaviour, depression and cognition of the male participants (Kenny et al., 2004). The testosterone levels were measured via blood samples, prior, during and after the 12 week cycle of testosterone or the placebo (Kenny et al., 2004). Depression was evaluated by self-report questionnaires which assessed depressive traits as well as aggressive traits (Kenny et al., 2004). Cognitive abilities were assessed on a separate test by the recognition of clock faces and abstract problem solving which were administered during each blood collection (Kenny et al., 2004). There were no significant findings on the participants in relation to depression or their cognitive functions, only their testosterone levels were higher in comparison to beginning the study (Kenny et al., 2004). It was concluded that testosterone replacement therapy may be productive and can be administered to men of older age without any depressive, aggressive or cognitive complications (Kenny et al., 2004). The study failed to find any significant relationship between testosterone and depression for the better or worse, nor with cognitive function (Kenny et al., 2004).

Rohr (2002) discussed and evaluated the potential impact an imbalance of testosterone may have on women and their mental health with a focus on depression. The possible delivery methods and side effects were also discussed in relation to administering testosterone replacement therapy to women who are suffering from depressive symptoms (Rohr, 2002). Testosterone in females is predominantly produced in the ovaries of women and the daily production is 5% of the daily production in men (Rohr, 2002). Androgenic hormones such as testosterone decline in women as they age, specifically between 20 and 40 years (Rohr, 2002). In correspondence with menopause, testosterone, although significantly low, remains at a constant level between the ages of 40 to 60 for females (Rohr, 2002). In an attempt to counteract depression in women during their menopausal transition, hormone replacement therapy has existed with a surplus of oestrogens (steroidal hormones which enhance feminine characteristics) to decrease the risk of heart attack and osteoporosis; it has not been effective in uplifting depressive moods or emotional well-being (Rohr, 2002). A suggestion has been made that testosterone replacement therapy may assist in treating depressive symptoms and emotional states of women who are complaining of fatigue, low libido and a diminishing well-being (Rohr, 2002). Androgenic deficiencies may be a supporting factor in the depression of women and the integration of testosterone to revive depreciated levels may be beneficial (Rohr, 2002). Furthermore, thorough research on administering testosterone to females with the goal to deter depressive symptoms and encourage a positive emotional state has been suggested for the future (Rohr, 2002).

Testosterone and mood
The effects of testosterone on mood in men have been reviewed by Johnson et al., (2013). The effects of testosterone were summarised after examining various studies with discussion on the variables of high and low testosterone in men (Johnson et al., 2013). There has been an increase in curiosity on the implication of testosterone and how it affects men as testosterone deficiencies are increasing worldwide (Johnson et al., 2013). The testosterone replacement therapy (TRT) market is also increasing in its popularity within the pharmaceutical industry as a result of more men requiring TRT as a means to revive multiple physiological and psychological aspects of their well-being (Johnson et al., 2013). Synthetic testosterone is formulated in various forms to be either injected intramuscularly, received orally in tablet form or as gel which is applied on the body (Rohr, 2002). Replacing testosterone has been shown to repair various complications in men who are suffering from low testosterone or hypogonadism (Johnson et al., 2013; Wang et al., 2008). Problems with libido, focus, sleep, mood and cognition (which can be symptoms of many mood disorders) have been suggested to be improved by TRT (Johnson et al., 2013).

A majority of the studies regarding the implications of high testosterone on mood, have had to assess men through external methods of administering high levels of testosterone as it is difficult to obtain reasonable sample sizes of men with naturally elevated testosterone levels (Johnson et al., 2013). Research thus far on naturally high testosterone on mood, suggests an increased chance of risk taking or aggressive behaviour (Olweus et al., 1988; Johnson et al., 2013). However, there is no substantial evidence to indicate the prevalence of mood disorders as a result of naturally elevated testosterone (Johnson et al., 2013). O’Connor, Archer and Wu (2004) conducted a placebo-controlled investigation on the moods and behaviours of men who were administered 1000mg of testosterone. Twenty-eight male participants satisfied the physical criterion and were recruited for this study (O’Connor et al., 2004). Participants were randomly assigned to receive 1000mg of testosterone or placebo under double-blind, cross-over circumstances throughout a 16 week cycle with regular monitoring and follow ups (O’Connor et al., 2004). Mood, behaviour and sexual behaviour were assessed through self report measures (O’Connor et al., 2004). The most significant finding was that those who had been intramuscularly injected 1000mg of testosterone reported an increase of anger and hostility in comparison to those who took placebo (O’Connor et al., 2004). Additional studies on elevated testosterone and how it affects the moods of males have been prevalent in the investigations of anabolic steroids being administered to participants (Johnson et al., 2013). However, such studies go beyond the scope that is relative to natural testosterone or rejuvenating natural testosterone levels.

Research on low testosterone and mood has had a dominant focus towards its relationship with depression. The effects of low testosterone on mood have been recorded to have associations with depressive symptoms (Amore et al., 2012; Johnson et al., 2013). Men who have low testosterone often tell their clinicians that they are experiencing a loss of libido, irritability, fatigue and dissatisfaction with life (Amore et al., 2012; Johnson et al., 2013). These neuropsychiatric symptoms can be relative to factors which may lead to major depression in men (Amore et al., 2012; Johnson et al., 2013). There is no direct causal link between depression and low testosterone thus far, however, there are multiple studies which document correlations between depression and low testosterone (Amore et al., 2012; Johnson et al., 2013).

Conclusion
Research on testosterone, what it is and how it affects aggression, depression and mood has been addressed within this chapter. The challenge hypothesis is a theory which has attempted to explain the link between testosterone and aggressive behaviour. It is intended that a sufficient understanding on testosterone and its relationship with emotion has developed from reading the content within this chapter. Now that you have been able to understand how important testosterone is in a males health, it may encourage you to let others know about testosterone replacement theory. It may develop more discussions on low testosterone amongst peers, removing the taboo on such a topic and be able to identify symptoms of hypogonadism. May the testosterone be with you in a functional, healthy life full of positive emotions.


 * Don't forget
 * Testosterone is an important hormone for men's health, specifically in sexual health as well as physical health
 * The Challenge Hypothesis attempts to explain testosterone fuelled aggression in males
 * Unnaturally high levels of testosterone may contribute to feelings of anger or hostility
 * There are correlations between low testosterone and experiencing depressive symptoms
 * Above average levels of testosterone may warrant antisocial or risk taking behaviour if the individual is not happy with either marriage or employment
 * Hypogonadism is a serious issue in mens health which can be treated by testosterone replacement therapy

Quiz
{Testosterone is a? - Roid + Steroidal hormone - Needle - Vial
 * type=""}

{ Low testosterone may lead to? - Acne - Increased libido - Happiness + Hypogonadism
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{ The Challenge Hypothesis was originally conceptualised for? - Aliens + Birds - Dogs - Lions
 * type=""}

{ TRT is? + Testosterone Replacement Therapy - Test Reviving Tren - Testosterone Rejuvenation Tactic - Test Real Test
 * type=""}