I watched a great FA Cup football final last night, and was amused as always when players confronted each other after tackles with aggressive postures and pouting anger-filled stares – all occurring in front of a huge crowd looking on and under the eyes of the referee to protect them. On Twitter yesterday and this morning I was engaged in a fun scientific debate with some male colleagues and noted that each time the arguments became ‘ad hominem’ the protagonists became aggressive and challenging in their responses, and only calmed down and became civil again when they realized it is banter. I have over many years watched my wonderful son grow up daily, and now he is ten have observed some changes occurring in him that are related to increasing development of ‘maleness’ which occurs in all young men of his age. In my twenties while completing my medical and PhD training, I worked part time as a bouncer, and it was always fascinating to see the behaviour of males in the bars and clubs I worked in then change when around females ‘dressed to kill’ and out for the evening. With the addition of alcohol this became a dangerous ‘cocktail’ late in the evenings, with often violence breaking out as the young men tried to establish their dominance and ‘turf’, or as a result of perceived negative slights which ‘honour’ demanded they respond to, and which resulted in a lot of work for me in the bouncer role to sort out. All this got me thinking of the male hormone testosterone and its effect on males through their lifetime, both good and bad.
Testosterone is the principal male sex hormone that ‘creates’ the male body and mind from the genetic chromosomal template supplied at conception. It is mostly secreted by the testicles in men, and to a lesser degree from the ovaries in women, with some secretion also from the adrenal glands. There is approximately 7-8 times higher concentration of testosterone in males than females, but it is present also in females, and females are susceptible to (and may even be more sensitive to) its actions. Testosterone is a steroid type hormone, derived originally from cholesterol related chemical substances which are turned into testosterone through a complex pathway of intermediate substances. Its output from the testes (or ovaries) is stimulated by a complex cascade of neuro-hormonal signals that arise from brain structures (gonadotrophin release hormone is released by the hypothalamus structure in the brain and travels to the pituitary gland, which in turn releases luteinizing hormone and follicle stimulating hormone, which travels in the blood to the testicles and in turn cause the release of testosterone into the bloodstream) in response to a variety of external and internal stimuli (though what controls testosterone’s release, and how it is controlled, in this cyclical manner over many years is almost completely unknown). The nature of ‘maleness’ has been debated as a concept since antiquity, but it was in the 1800’s that real breakthroughs in the understanding that there was a biological basis to ‘maleness’ occurred, with hormones being identified as chemical substances in the blood, and several scientist folk such as Charles Brown-Sequard doing astonishing things like crushing up testicles and injecting the resultant product into their own bodies to demonstrate the ‘rejuvenating’ effect of the ‘male elixir’. Eventually in the late 1800’s testosterone was isolated as the male hormone – it was named as a conglomerate derivative of the words testicle, sterol and ketone – and in the 1930’s, the ‘golden age’ of steroid chemistry, its structure was identified, and synthetic versions of testosterone were produced as medical treatment analogues for folk suffering from low testosterone production due to hypogonadism (reduced production of testosterone due to testicular function abnormality) or hypogonadotropism (reduced production of testosterone due to dysfunction of the ‘higher’ level testosterone release control pathways in the brain described above).
Testosterone acts in both an anabolic (muscle and other body tissue building) and androgenic (male sex characteristic development) manner, and one of the most fascinating things about it is that it acts in a ‘pulsatile’ manner during life – increasing dramatically at very specific times in a person’s life to effect changes that are absolutely essential for both the development and maintenance of ‘maleness’. For example, in the first few weeks after conception in males there is a spike in testosterone concentration in the foetus that results in the development of genitals and prostate gland. Again, in the first few weeks after birth testosterone concentrations rise dramatically, before attenuating in childhood, after which a further increase in the pre-puberty and the pubertal phases occurs, when it is responsible for increases in muscle and bone mass, the appearance of pubic and axillary hair, adult-type body odour and oily skin, increased facial hair, deepening of the voice, and all of the other features associated with (but not all exclusive to) ‘maleness’. If one of these phases are ‘missed’, normal male development does not occur. As males age, the effects of continuously raised testosterone associated with adulthood become evident as loss of scalp hair (male pattern baldness) and increased body hair, amongst other changes. From around the age of 55 testosterone levels decrease significantly, and remain low in old age. Raised testosterone levels have been related to a number of clinical conditions that in the past have been higher in males than females, such as heart attacks, strokes and lipid profile abnormalities, along with increased risk of prostate (of course it’s not surprising that this is a male specific disorder) and other cancers, although not all studies support these findings, and the differences in the gender-specific risk of cardiovascular disorders in particular is decreasing as society has ‘equalized’ and women’s work and social lives have become more similar to those of males in comparison to the more patriarchal societies of the past.
More interesting than the perhaps ‘obvious’ physical effects are the psychological effects of testosterone on ‘male type’ behaviour, though of course the ‘borders’ between what is male or female type behaviour are difficult to clearly delineate. Across most species testosterone levels have been shown to be strongly correlated with sexual arousal, and in animal studies when an ‘in heat’ female is introduced to a group of males, their testosterone levels and sex ‘drive’ increases dramatically. Testosterone has also been correlated with ‘dominance’ behaviour. One of the most interesting studies I have ever read about was one where the effect of testosterone on monkey troop behaviour was examined, in which there are strict social hierarchies, with a dominant male who leads the troop, submissive males who do not challenge the male, and females which are ‘serviced’ only by the dominant male and do not challenge his authority. When synthetic testosterone was injected into the males, it was found that the dominant male become increasingly ‘dominant’ and aggressive, and showed ‘challenge’ behaviour (standing tall with taught muscles in a ‘fight’ posture, angry facial expressions, and angry calls, amongst others) more often than usual, but in contrast, there was no effect or change of the testosterone injections on non-dominant male monkeys. When the females were injected with testosterone, most of them became aggressive, and challenged the dominant male and fought with him. In some cases the females beat the dominant male in fighting challenges, and became the leader of the troop. Most interestingly, these ‘became dominant’ females, when the testosterone injections were discontinued, did not revert back to their prior submissive status, but remained the troop leader and maintained their dominant behaviour even with ‘usual’ female levels of testosterone. This fascinating study showed that there is not only a biological effect of testosterone in social dominance and hierarchy structures, but that there is also ‘learned’ behaviour, and when one’s role in society is established, it is not challenged whatever the testosterone level.
Raised testosterone levels have also been linked with level of aggression, alcoholism, and criminality (being higher in all of these conditions) though this is controversial, and not all studies support these links, and it is not clear from the ‘chicken and egg’ perspective if increased aggression and antisocial behaviour is a cause of increased testosterone levels, or is a result of it. It is also been found that athletes have higher levels of testosterone (both males and females) during sport participation, as have folk watching sporting events. In contrast, both being ‘in love’ and fatherhood appears to decrease levels of testosterone in males, and this may be a ‘protective’ mechanism to attenuate the chance of a male ‘turning against’ or being aggressive towards their own partners or children. Whether this is true or not requires further work, but clearly there is a large psychological and sociological component to both the functionality and requirements of testosterone, beyond its biological effects. One of the most interesting research projects I have been involved with was at the University of Cape Town in the 1990’s, where along with Professor Mike Lambert and Mike Hislop, we studied the effect of testosterone ingestion (and reduction of testosterone / medical castration) on male and female study participants. We found not only changes in muscle size and mass in those taking testosterone supplements, but also that participants ingesting or injecting testosterone had to control their aggression levels and be ‘careful’ of their behaviour in social situations, while women participants described that their sex drive increased dramatically when ingesting synthetic testosterone. In contrast, men who were medically castrated described that their libido was decreased during the study time period when their testosterone levels were reduced by testosterone antagonist drugs to very low levels (interestingly they only realized this ‘absence’ of libido after being asked about it). All these study results confirm that testosterone concentration changes induce both psychological and social outcomes and not just physical effects.
Given in particular its anabolic effects, testosterone and its synthetic chemical derivatives, known commonly as anabolic steroids, became attractive as a performance enhancing drug by athletes in the late 1950’s and 1960’s as a result of it being massed produced synthetically from the 1930’s, and as athletes became aware of its muscle and therefore strength building capacity after its use in clinical populations. Until the 1980’s, when testing for it as a banned substance meant it became risky to use it, anabolic steroids were used by a large number of athletes, particularly in the strength and speed based sporting disciplines. Most folk over 40 years old will remember Ben Johnson, the 1988 Olympic 100m sprint champion, being stripped of his winner’s medal for testing positive for an anabolic steroid hormone during a routine within-competition drug test. Testosterone is still routinely used by body-builders, and worryingly, a growing number of school level athletes are being suggested to be using anabolic steroids, as well as a growth of its use as a ‘designer drug’ in gyms to increase muscle mass in those that have body image concerns. An interesting study / article pointed out that boy’s toys have grown much more ‘muscular’ since the 1950’s, and that this is perhaps a sign that society places more ‘value’ on increased muscle development and size in contemporary males, and this in a circular manner probably puts more pressure on adolescent males to increase their muscle size and strength due to perceived societal demands, and thereby increases the pressure on them to take anabolic steroids. There is also suggested to be an increase in the psychological disorder known as ‘muscle dysmorphia’ or ‘reverse anorexia’ in males, where (mostly) young men believe that no matter how big they are muscle size wise, they are actually thin and ‘weedy’, and they ‘see’ their body shape incorrectly when looking in the mirror. This muscle dysmorphia population is obviously highly prone to the use of (perhaps one should say abuse) anabolic steroids as a group. There appears to be also an increase in anabolic steroid use in the older male population group, perhaps due to a combination of concerns about diminishing ‘male’ function with increasing age, a desire to maintain sporting prowess and dominance, and a perception that a muscular ‘body beautiful’ is still desirable by society even in old age – which is a concern due to the increased cardiovascular and prostate cancer risks taking anabolic steroids can create in an already at-risk population group. There is also a growth in the number of women taking anabolic steroid / synthetic testosterone, both due to its anabolic effects and its (generally) positive effects on sex drive, and a number of women body builders use anabolic steroids for competitive reasons due to its anabolic effect on muscles, despite the risk of the development of clitoral enlargement, deepening voice, and male type hair growth, amongst other side effects, which potentially can result from females using anabolic steroids. Anabolic steroid use therefore remains an ongoing societal issue that needs addressing and further research, to understand both its incidence and prevalence, and to determine why specific population groups choose to use them.
It has always been amazing to me that a tiny biological molecule / hormone, which testosterone is, can have such major effects not only on developing male physical characteristics, but also on behavioural and social activity and interactions with other folk, and in potentially setting hierarchal structures in society, though surely this ‘overt’ effect has been attenuated in modern society where there are checks and balances on male aggression and dominance, and females now have equal chances to men in both the workplace and leadership role selection. Testosterone clearly has a hugely important role in creating a successfully functioning male both personally and from a societal perspective, but testosterone can also be every males ‘worst enemy’ without social and personal ‘higher level’ restraints on its potential unfettered actions and ways of working. It has a magic in its function when its effects are seen on my young son as he approaches puberty and suddenly his body and way of thinking changes, or when its effects are seen (from its diminishment) in the changes of a man in love or in a new father. Perhaps there is magic also in the reduction of testosterone that occurs in old age, as this is likely to be important in allowing the ‘regeneration’ of social structures, by allowing new younger leaders to take over from previously dominant males, by this attenuation of testosterone levels perhaps making older males ‘realize’ / more easily accept that their physical and other capacities are diminished enough to ‘walk away’ gracefully from their life roles without the surges of competitive and aggressive ‘feelings’ and desires a continuously high level of testosterone may engender in them if it continued to be high into old age. But testosterone has an ugliness in its actions too, which was evident in my time working as a bouncer in bars and clubs, when young men became violent with other young men as a way of demonstrating their ‘maleness’ to the young females who happened to be in the same club and were the (usually) unwitting co-actors in this male mating ritual drama which enacted itself routinely on most Friday and Saturday nights, usually fuelled by too much alcohol. Its ugliness is also evident on the sporting field when males kick other men lying helpless on the ground in a surge of anger due to losing the game or for a previous slight, despite doing so within the view of a referee, spectators and TV cameras. Its ugliness is also evident in the violence that one sees in fans after a soccer game preying on rival fans due to their testosterone levels being high due to watching the game, and in a myriad of other social situations where males try to become dominant to lever the best possible situation or to attract the best possible mate for themselves, at the expense of all those around them – whether in a social or work situation, or a Twitter discussion, or even a political or an academic debate – the ‘male posturing’ is evident for all to see in each situation, whether it is physical or psychological. Perhaps it was not for the sake of a horseshoe that the battle was lost, but rather because of too little, or too much, testosterone coursing around the veins of those directing it. There are few examples as compelling as that of the function of the hormone testosterone in making male behaviour what it is which demonstrates how complex, exquisite and essential the relationship between biological factors and psychological behaviour and social interplay is. What truly ‘makes up’ a man and what represents ‘maleness’ though, is of course another story, and for another debate!