Essay: How is testosterone relevant to human social interactions?

How is testosterone relevant to human social interactions? Critically discuss what we do and do not know about the role of testosterone in the expression of social behaviour in humans.
Testosterone is a hormone that acts through androgen receptors and is essential for both the maintenance of a good quality of life (particularly in males’ due to the associated increase in secondary sexual characteristics such as muscle growth as a consequence of testosterone) and for the continuation of the human species due to its status as the primary male sex androgen. (Mooradian, Morley, & Korenman, 1987). The hormone is produced in the testes and ovaries for males and females respectively, however both sexes also secrete the hormone via the adrenal cortex. (Mazur & Booth, 1998). It has been suggested that testosterone is extremely relevant with regards to human social interactions as there is wealth of research into the association between increased testosterone levels and subsequent increases in aggressive behaviour – although this causal link is often stronger in animal studies in comparison to human studies (Kouri, Lucas, Pope, & Olivia, 1995). However, more recent evidence suggests that a stronger association can be assumed between testosterone and status seeking/ dominance behaviour, with a positive relationship between baseline testosterone level and corresponding status sensitivity. (Josephs, Newman, Brown, & Beer, 2003). Testosterone’s influence on both the social phenomena’s of aggression and status seeking behaviour can be accurately measured due to the improvements in the standardisation of the methodology used to test the aforementioned correlations, thus the relationships observed between the hormone and the subsequent social behaviour can now be critically evaluated (Rosner, Vesper & Endocrine Society the endorsing organisations, 2010).
One way in which testosterone is relevant to human social interactions is via its influence on the behaviour of aggression. Aggression can be defined as a “generic assertiveness which includes both constructive and destructive behaviours” (Rozenweig, 1977) and there is a weak positive relationship between the hormone and the behaviour, although this relationship is often viewed as controversial within the research community ( Book, Starzyk, & Quinsey, 2001).
An interesting hypothesis that explains testosterones’ direct influence on aggression is the challenge hypothesis (Archer, 2006). Archer (2006), argues that, akin to monogamous birds, testosterone levels will naturally increase when young males are subject to challenges, with the act of competition itself spurring a rise in aggressive behaviour. This hypothesis has been well supported by the works of Salvador, Martinez-Sanchis, Simon, & Brain (1999), whereby larger natural increases of testosterone level were correlated with participants being a more violent competitor and looking angrier whilst fighting, both classic signs of aggressive behaviour in the face of a challenge. Indeed, an additional study conducted by Salvador et al (1999), further suggests that pre-contest testosterone levels predict the degree of offensive fighting, with the participants with higher testosterone levels performing moves that represented ‘attack’ and ‘fighting’ more frequently in a judo match than those with lower levels of testosterone. The aforementioned research allows us to assume that the challenge hypothesis is supported as testosterone levels rise before and during a challenge, therefore facilitating aggression – although contradictory research by Salvador, Simon, Suay & Llorens (1987), casts doubt on the robustness of this hypothesis, suggesting that testosterone levels actually decrease after competition. In addition to this, we do not know whether testosterone is a cause or a consequence of aggression as the hormone wasn’t experimentally manipulated in this research as the experiments occurred in a natural setting, thus testosterone cannot be assumed to be the sole cause of aggressive behaviour. Furthermore, the actual act of aggression is a subjective behaviour, casting doubt on the measures of an “angry face’ as there is no definitive scale for measuring facial expression.
In order to investigate the causality of testosterone directly influencing aggressive behaviour, we must evaluate the effects of the artificial administration of testosterone in laboratories, such as the research conducted by Pope, Kouri, & Hudson (2000). 600mg a week of testosterone (or a placebo drug) was administered for 6 weeks in 56 male participants ranging from ages 20 to 50. The testosterone treatment greatly increased manic scores in daily dairies, manic scores on the young mania rating scale and also aggressive responses on the point subtraction aggression paradigm. This range of results suggests that testosterone does directly cause manic and aggressive behaviour in men. However, the results were variable as the levels of psychiatric effects varied between men, therefore it is unexplained as to why testosterone treatment effects some participants to a larger extent than others. In addition to this, the research focuses solely on male participants and therefore the effects of testosterone on women are questionable.
Contrastingly, research conducted by Dabbs & Hargrove (1997), focuses on female inmates, providing insight into the effects of testosterone with regards to women . 87 female inmates at a maximum-security prison were scored on their criminal behaviour using court records and prison records/interviews with staff, with their testosterone levels also recorded from a radioimmunoassay of saliva samples. Dabbs & Hargrove (1997), found a correlation between lower testosterone levels (as a result of increasing age) and decreased aggressive criminal acts and inmate misbehaviour. They proposed a causal model which provides an explanation of aggressive behaviour being caused by testosterone, although as testosterone wasn’t experimentally manipulated, other factors could’ve impacted behaviour. For example, aggressive traits may be exclusively demonstrated in prison as a means of survival amongst other inmate’s due to a hostile prison environment. Furthermore, factors such as socio-economic status may also cause aggressive behaviour and therefore causality cannot be demonstrated in this research.
Another way in which testosterone has helped researchers to understand social behaviour is by increased levels of the hormone being used to predict future aggressive behaviour – such as in studies by Carré &McCormick (2008). 38 male participants provided saliva samples before and after completing the point subtraction aggression paradigm – a task which provides an opportunity for aggressive behaviour and reward. Those who acted most aggressively had the highest increase in testosterone levels, supporting the challenge hypothesis mentioned previously by Archer (2006). However, in an interesting discovery, the males that showed this rise in testosterone were more likely to express the desire to compete in the aggressive task again. This therefore suggests that rising testosterone levels can predict aggressive behaviour – however further research is needed to account for males that experience this rise in testosterone but choose not to compete- thus diverting from the expected predications of behaviour.
A second way in which testosterone is relevant to human social behaviour is via its influence on status seeking behaviour. Social status can be defined as “relative access to contested resources within a social group” (Von Rueden, Gurven, & Kaplan, 2010) , with higher testosterone levels being associated with a higher social status ranking and increased dominance behaviours (Grant & France, 2001). This correlation between testosterone and status seeking behaviour is more widely supported than that of aggression, as demonstrated by the wealth of research mentioned below.
Mazur & Lamb (1980) explored the conditions needed to facilitate a rise in testosterone in line with status seeking behaviour. The research consisted of three experiments with testosterone being measured via blood samples , one whereby a tennis match was held, one whereby a random lottery draw was held and one whereby a graduation ceremony took place. Testosterone levels increased significantly after the match for the winner but only if there was a significant difference between the score of the winner and loser. During the lottery draw testosterone levels remained the same for winner and loser. After graduation, testosterone levels continued to rise in the participants for 1 to 2 days after the ceremony. These experiments lead us to draw the conclusion that testosterone rises when the participant’s status has been increased by his own effort (such as in the tennis match and graduation ceremony) but not if the rise in status was due to means outside his control. Therefore, a link between testosterone and status seeking behaviour can be assumed, as long as the rise in status has occurred by the participants own effort expenditure. However, there is still a lot that we don’t know about this trend, such as why testosterone doesn’t increase if the rise in status occurs randomly and why testosterone increases immediately after a tennis match but gradually after graduation. Thus, the correlation between status and testosterone requires further exploration.
Another aspect of the relationship between testosterone and status seeking behaviours is the ability to predict future status seeking behaviour in line with testosterone increase. Research by Mehta & Josephs (2006), saw 64 male participants provide saliva samples immediately before and after a rigged competition that saw them become the winner or the loser. An increase in testosterone of the loser after the competition made the participant more likely to want to compete again compared to losers who decreased in testosterone level and were subsequently less likely to want to compete. This could be due to the fact that those whose testosterone levels increased wanted to compete again to improve their status and those whose testosterone levels decreased wanted to avoid further status loss. Thus, the experiment suggests that testosterone is a key component involved in the motivation that humans experience to perform status seeking behaviours. However, the experiment didn’t allow an opportunity to explore whether winners that increased in testosterone would take the opportunity to increase their status further and compete against a more prestigious opponent, leaving a gap for further exploration. Furthermore, testosterone can’t be seen to directly cause status seeking behaviour as it wasn’t directly manipulated.
In addition to this, testosterone also influences social behaviour via the mismatch effect (Josephs, Sellers, Newman, & Mehta, 2006). Research by Josephs et al (2006), examined the effects of a mismatch between testosterone level and status whereby those with high testosterone levels were given low status and vice versa. The mismatch between these two components resulted in decreased cognitive functioning and greater emotional arousal, suggesting that testosterone levels could predict where participants fit into society in terms of status. The theory is robust as it has been replicated by the same researchers many times however it is unclear whether testosterone levels would balance out over time to match the participants newly acquired mismatched status level in the real world – as it is impractical to assume that hormones can limit the status we acquire in the world of work. Thus, the aforementioned effect may be of short term significance until it is proved otherwise.
However, recent research suggests that testosterone isn’t the only mechanism that effects status seeking behaviour. Mehta & Josephs (2010), found that testosterone and cortisol jointly facilitate dominance behaviours. Their research concluded that the relationship between increased testosterone level and increased status seeking behaviour was only facilitated when the participant had low cortisol levels. In contrast, when the participant had higher cortisol levels the relationship was blocked or reversed, suggesting that hormones other than testosterone jointly manage status seeking behaviour. However, the hormones weren’t experimentally manipulated and therefore it is impossible to deduct whether cortisol or testosterone had a larger impact on dominance behaviours in isolation, leaving room for further exploration.
Overall, there is more convincing evidence for testosterone’s effect on status seeking behaviours in comparison to testosterone’s impact on aggressive behaviour, due to the more consistent results that status seeking research holds. Within both areas of research there is often the issue of causality when the hormones aren’t experimentally manipulated (for example Salvador et al, 1999) and, contrastingly, the issue of generalisability when the hormones are artificially administered (for example Pope & Hudson, 2000). Thus, it is essential to evaluate a range of natural and artificial research to draw valid conclusions. In conclusion, testosterone is extremely relevant to human interactions however further research must be completed on female and child participants to further extend our knowledge of the hormone and its associated effects on behaviour.