Testosterone and Behaviour
Testosterone is generally a male hormone, from the androgen group. The hormone is secreted in testes of males. However, small amounts of the hormone are secreted in the ovaries of females and by the adrenal glands (Mehta, Jones and Josephs, 2008). This is the reason why the hormone is in higher levels in males than females. Studies have revealed the fact that the hormone has some effect on human behaviour. Hormones have been associated with behaviour as evident in the impact its presence or absence has on a human being. Testosterone reveals its hormonal and behavioural impacts when it interacts with androgen or estrogen receptors (Van Goozen, 1994). Some researchers have argued that there are “critical time period” when the hormone operates a sensitizer of some specific neural circuits in the mind. It is presumed that this sensitization is provides for the influences of the hormone that are manifested as someone grows.
There has been another hypothesis that has built upon this claiming that the hormone leads to the development of an “androgen-responsive system” in men (Dabbs, 1990). There is also an assumption that there are similar effects in females though to a lesser degree. Despite the fact that it is not the basic function of many hormones, neutral action can be motivated by their presence. For instance when testosterone acts on a targeted neuron, the level of neurotransmitter released is adversely affected. For instance, tentative data has been used to suggest that the hormone acts on serotonergic synapses and reduces the level of 5-HT that is present for synaptic transmission. This crucial when linked with the fairly well accepted notion that the availability of high amount of 5-HT serves to limit aggressive behaviour. This is convincingly revealed in studies carried out on male rhesus monkeys. The conclusion is that Serotonin reuptake inhibitors for example the Fluoxentine cause a remarkable reduction in aggressiveness in both monkeys and human beings (Swaab and Garcia-Falgueras, 2009).
In the prenatal stage, the hormone builds the muscular system of the fetus, while in grown ups the hormone has more effects. Experiments have revealed the fact those women having high levels of testosterone tend to be more sexually active, take a lot of alcohol, engage in more competitive experiences and behave in more masculine manner than those who have lower levels. Most of these characteristic are prevalent in men. It has also been revealed that criminals with more testosterone tend to commit more serious crimes and misbehave in prison that their counterparts who have lower levels of the hormone. Baron-Cohen (2003) men required systemising skills to make it possible for them to invent tools and equipments that would enable them hunt and gain more status in the society. Testosterone has been connected with the differences in the behaviour and characteristics between women and men. Men tend to have more of the hormones as compared with women (Lutchmaya, Baron-Cohen and Raggatt, 2002).
The practical is aimed at proving whether there is a relationship between testosterone and behaviour such as autistic traits and whether testosterone related tests can be used to tell sex differences.
Testosterone across gender
It is obvious that despite the fact that some human behaviours cuts across the gender, there are those that are specific to males and others to females. Popular culture as well as some experiments supports the fact that the differences are as a result of this particular hormone.
The effects of testosterone on behaviour vary from males and females. According to Baron-Cohen (2003) Men and women underwent different pressures and circumstances during their evolution. This is in terms of the hunter-gatherer experiences. The differences are also manifested in possibility of there being sex differences in Theory of Mind capacities. The research argues that women are better in understanding the feelings and desires of other people as compared to men. This means that women are good empathisers. Men on the other hand are good systemisers. This is because men are good at building systems and making them work. It is argued that testosterone makes men selfish and controlling. They always want to see things done from their point of view (Baron-Cohen, 2003). To test the empathising and systematising abilities, the following test was used.
Empathy Quotient (EQ) and Systemising Quotient (SQ)
Baron-Cohen has developed two separate tests for these attributes; the Empathy Quotient (EQ) and the Systemising Quotient (SQ). These tests are based on self reports of an individual’s abilities, interests and beliefs about various day-to-day experiences. These take the form of comments that ask the individual to either agree with or disagree with, for example: It upsets me to see an animal in pain strongly slightly slightly strongly
agree agree disagree disagree (Baron Cohen, 2003).
Testosterone and autistic traits
This study is cantered on this subject. The effects of testosterone on behaviour have also been analysed in terms of prenatal levels. The exact measure used in this analysis is second-to-fourth digit ratio (2D:4D). They results have revealed a relationship between the levels and behavioural traits like sporting and musical capabilities. This means that high (2D:4D) shows higher level of abilities in individuals, while low (2D:4D) shows low level of abilities. This is the reason the ratio has been used as a predictor of autistic traits. Researches have revealed the fact that those people who are autistic as well as their parents tend to have low (2D:4D) (Lutchmaya et al., 2002). Geschwind and Galaburda (1985) argued that from their research they discovered that high levels of prenatal testosterone, shown by low 2D:4D are linked to autistic traits. In a research where autism is described as a disorder of the “extreme male brain” the researcher argues that fetuses exposed to high levels of prenatal testosterone are more danger of developing autism. This is basically the reason why some of the autistic patients tend to be hyperactive as compared to their counterparts who are health and have high 2D:4D (Manning et al., 2002). Additionally in some previous researches it was discovered that children with high prenatal testosterone tend to make less eye contact and have basic problems with language. Some other studies present findings revealing the fact the children with higher levels of prenatal testosterone have lower social skills and are more restricted in their interests (Knickmeyer et al., 2005). This is the reason why autism is typified by impaired development in social and communication capabilities. All these findings match and present the fact that high level of prenatal testosterone is associated with autistic traits (Lutchmaya et al., 2002).
‘Reading the Mind in the Eyes’
Baron-Cohen has also devised a further test of empathy, and that is the ‘Reading the Mind in the Eyes’ test. Here, individuals are presented with a series of photographs of a pair of human eyes that are expressing an emotion. Each photo is accompanied by a list of four different emotions, and the participant has to select which of these emotions the eyes are portraying. It is predicted that as empathy involves being able to understand and acknowledge the emotional states of others through non-verbal cues, then a high score in this test is indicative of a high empathic ability (Baron Cohen, 2003).
The reason for the association between high level of prenatal testosterone and autistic traits is because prenatal testosterone tends to affect the growth of some parts of the brain. Conventionally, autism is defined as a developmental disorder that has irregularities in communication, socialization and stereotypical abnormal characteristics. Autism is a disorder of neural development that is typified by impaired development in social and communication capabilities. This problem is known to affect the information processing capability of the brain. Children suffering from this disorder tend to have delay in, and deviation from the usual patterns of development. Autism in children takes place in three main areas of development: social interactions and interrelations; communication; and activities and interests. Where a child is seen to have difficulties in these three areas of development, and normally at a higher degree than in normal children, then it can be realized that the child might be suffering this disorder. This means that autism occur when prenatal testosterone affect the information processing part of the brain. The higher the level of the hormone, the faster the right hemisphere of the brain develops. This part of the brain is linked to special capability, which is a significant element of systemising. The left part of the brain the one that is associated with language and communication development, which is a significant element of empathising. Due to the fact that males have higher levels of the hormone, this is the reason why they are good at systematising than their counterparts. The high ability of empathising is inherent in females on the other hand since they have lower levels of the hormone. Systematisers are good at recognising rules and patterns. According to Baron-Cohen the characteristics of systematisers are the same characteristics that define autism. This is what led the researcher to the conclusion that the disorder is one of the extreme male brains. Autism is known to be about three or four times as common in males than females.
In a research conducted by Baron-Cohen and published in the British Journal of Psychology, he studied 235 pairs of children and their mothers. All the children who were over eight years were provided with questionnaires. The questionnaires were meant to measure autistic traits in the children. There was no child in the experiment who was diagnosed with the disorder. However, the researcher noted the fact that children who were exposed to high prenatal testosterone, measured through amniocentesis before birth, were at a greater risk of developing autistic straits. From the research, Baron-Cohen conclude that the research indicates for the first time the link between prenatal testosterone and autistic traits and reveals the fact that fetal testosterone not only makes the body masculine, but also the brain. All the questionnaires administered by Baron-Cohen that score higher in autistic traits score higher in males than females (Baron Cohen, 2003).
The results from the researches by Baron-Cohen could one day lead to screening tests for autism. The results also reveal the fact that, as many have speculated, a genetic condition. Many of the researchers have concluded that the condition is an extreme male behaviour. This study is in a way related to this hypothesis. In the research seventy pregnant women were exposed to amniocentesis. This research was also headed by Baron-Cohen. After birth, he was able to do a follow up on the children when they were four years old. He studied the seventy children in details. When they attained the age of four, their mothers were require to fill a checklist. The checklists were developed to capture any indication of behavioral and social difficulties. Essentially, they were designed to capture any forms of autistic-related traits. From the study it was revealed that those children who had higher levels of prenatal testosterone had difficulties fitting in social groups. He also explained in a British Psychological Society’s annual meeting that in the cases where the mother had high levels of testosterone in the uterus, their babies tended to be less curious than their counterparts. He concluded that despite the fact that the children were not diagnoised with autism, they tended to exhibit slight signs of autistic-like characteristics. He added that at twelve months those children whose mothers had high levels of the hormone were less willing to maintain eye contact. These researches also reveal the fact that sexes are different (Knickmeyer, Baron-Cohen, Raggatt and Taylor, 2005).
Testosterone is a predictor of sex differences. This is the reason why it is possible to predict relationships between 2D:4D ratio and the following: EQ, SQ, Mind in the Eyes. As already seen from various researches males tend to have more of the hormone than females. This is the reason why they are systematisers while women are empathisers. This is also the reason why males are more masculine than females, not only in their bodies, but also their minds. Based also on the characteristics and abilities of the different categories of participants it is possible to predict the relationships. The research is generally a proof of the fact that the tests developed by Baron-Cohen can reveal the relationship between prenatal testosterone and sex, and characteristics across sexes.
Baron-Cohen, S. (2003). The Essential Difference: The Truth About the Male and Female Brain.
London: Penguin Books.
Chapman, E., Baron-Cohen, S., Auyeung, B., Knickmeyer, R., Taylor, K., ; Hackett, G. (2006).
Foetal testosterone and empathy: evidence from the Empathy Quotient (EQ) and the ‘Reading the Mind in the Eyes’ Test’. Social Neuroscience. 1:135-148.
Dabbs, J. M. Jr. (1990). Salivary testosterone measurements: Reliability across hours, days, and
weeks. Physiol Behav 48:83—86,
Geschwind, N., & Galaburda, A. M. (1985). Cerebral lateralisation: biological mechanisms,
associations and pathology. II. A hypothesis and a program for research. Archives of Neurology, 42: 521-552.
Knickmeyer, R., Baron-Cohen, S., Raggatt, P., & Taylor, K. (2005a). Foetal testosterone, social
relationships, and restricted interests in children. Journal of Child Psychology and Psychiatry, 46: 198-210.
Lutchmaya, S., Baron-Cohen, S., & Raggatt, P., (2002). Foetal testosterone and vocabulary size
in 18- and 24-month-old infants. Infant Behavior and Development, 24:418-424.
Manning, J.T., Baron-Cohen, S., Wheelwright, M.A., & Sanders, G. (2001). The 2nd to 4th digit
ration and autism. Developmental Medicine and Child Neurology, 43: 160-164
Mehta, P. H., Jones, A.C., & Josephs, R. A. (2008). The social endocrinology of dominance:
basal testosterone predicts cortisol changes and behavior following victory and defeat. J Pers Soc Psychol 94 (6): 1078–93.
Swaab, D., & Garcia-Falgueras, A. (2009). Sexual differentiation of the human brain in relation
to gender identity and sexual orientation. Funct. Neurol. 24 (1): 17–28.
Van Goozen, S (1994). Male and female: Effects of sex hormones on aggression, cognition, and
sexual motivation. Amsterdam: University of Amsterdam.