Transsexuality is different from homosexuality and is shown when an individual is absolutely certain that he or she belongs to the opposite sex; this may lead him or her to seek sex-reassignment surgery. Transsexuality can be caused by hormones and chromosomal abnormalities. A study of male-to-female transsexuals found that they were more likely than normal men to have a long version of a gene that reduces testosterone binding to cells in the developing embryo. In the brains of male-to-female transsexuals, the nucleus of the stria terminalis (BSTc) was found to be characteristically more female in size and in number of neurons. Similarly the INAH-3 in male-to-female transsexuals was found to be small and of female size and cell number. Conversely a female-to-male transsexual subject was found to have an INAH-3 volume within the male range, even though treatment with testosterone had been stopped three years before. Another female-to-male transsexual subject had a BSTc and INAH-3 with clear male characteristics. This sex reversal of the INAH-3 in transsexual people may indicate an early atypical sexual differentiation of the brain, and changes in both the INAH-3 and BSTc may be part of a complex brain network related to gender identity and sexual orientation. The present data do not support the notion that brains of male-to-female transsexuals are feminised, but they do have smaller BSTc regions than both heterosexual and homosexual men. On the other hand, female to male transsexuals were shown in a study to have four regions of white matter, which normally differ significantly between the sexes, in areas that resembled a male brain, indicating that they were masculinised. A girl with CAH will have a small increased chance of becoming transsexual. About three per cent of women with CAH want to live as men in adulthood, despite having been reared as girls.
There are a few reports of families where there are several transsexual individuals. A handful of twin studies have been conducted, but they are inconclusive and have shown differing rates for transsexualism. But some transsexuals show chromosomal abnormalities and all these cases involved the sex chromosomes. A major output pathway of the amygdala and part of the hypothalamus are about twice as large in men as in women, but in male-to-female transsexuals these differences were absent.
Men have the distinction of being responsible for abnormal, criminal sexual behaviours like rape, which might be seen as a kind of perverted sexual strategy to gain access to females, and paedophilia, the causes of which are not yet clearly understood. An estimated 85,000 women a year are victims of rape or sexual assault by penetration in England and Wales according to a 2013 report by the United Kingdom’s Ministry of Justice. One in twenty women aged between sixteen and fifty-nine is raped or suffers a serious sexual assault before the age of sixty, and one in five women has suffered some form of sexual molestation. There do not seem to be any strong biological mechanisms for preventing sex between adults and children except with respect to incest. Abnormal sexual behaviour is shown by paedophiles who have distinct characteristics and whose preferred sexual objects are children. What causes paedophilia is not known, but recent investigations have concentrated on the brain and its functions. Male paedophiles tend to have lower IQs, possibly suffered childhood head injuries and have been shown by MRI scans to have differences in their brain structure. But in some societies such sexual activity has been thought acceptable. When Captain Cook visited Tahiti he was astonished to find that the Tahitians ‘gratified every appetite and passion before witnesses’ by having sexual intercourse in public. He reported in his Account of a Voyage Around the World (1769):
A young man, nearly six feet high, performed the rites of Venus with a little girl about 11 or 12 years of age, before several of our people and a great number of natives, without the least sense of its being indecent or improper, but, as appeared, in perfect conformity to the custom of the place. Among the spectators were several women of superior rank who . . . gave instructions to the girl how to perform her part, which, young as she was, she did not seem much to stand in need of.
8
Emotions
I would rather trust a woman’s instinct than a man’s reason.
Stanley Baldwin
It is widely believed that women are more emotional than men, and this gender stereotype is supported by a body of scientific research. Women show their emotions more than men and are more facially expressive for both positive and negative emotions. They are also better than men in reading emotional facial expressions both in adults and children, and they show a stronger emotional response than men when looking at or listening to infants. Women also use emotional terms to describe themselves and others several times more frequently than men. They express more emotions more frequently and have stronger emotional responses when viewing images of facial expressions such as fear, sadness and embarrassment. Men, by contrast, are believed to feel and express anger and pride more often and more strongly, and we shall see this particularly in relation to aggression.
A major difference between the emotions of men and women lies in this expression of aggression, for which men enjoy a pronounced physical advantage. Men, as already mentioned, are more physically aggressive than women, and men commit about ninety per cent of all murders and almost all sexual crimes. Crime statistics show that women account for only about six per cent of prison inmates, irrespective of nationality, culture, religion and age. One recent survey found that more than one in four women experience violence from an intimate partner at some stage in their lives. The greater frequency of male physical aggression is one of the strongest behavioural sex differences, regardless of many different age groups and cultures. It has an evolutionary origin, as discussed, and men tend to show less aggression against women than against other men. On the other hand, women can be equally aggressive towards men and other women, but their aggression tends to be much less physical as they are more likely to fear all kinds of events that might involve a physical injury. Women can be aggressive by using a number of non-physical means.
Aggression is linked most strongly to the amygdala, which is larger in men, and when influenced by testosterone can trigger aggression and stimulate competitiveness. The prefrontal cortex is the decision-making executive centre of the brain, and it controls emotional information and can put a check on the amygdala. The prefrontal cortex is larger in women and this enables them to look for solutions to conflict more effectively. As Ohrmann and his co-authors point out, significantly, stronger activation of the amygdala was observed in women than in men while looking at angry, fearful, or neutral facial expressions, but not at happy ones. Prenatal testosterone exposure directly relates to physical aggression and many studies have demonstrated this. Girls and women with CAH are more like males, with an increase in physical aggression and increased activity in the amygdala in response to negative facial emotions. The hormone cortisol increases aggressive behaviour in women, but not in men. So there is support for the view that healthy men and women derive their aggression from a different biological basis. There are also significant gender differences in the frequency of physical aggression from as early as seventeen months old, with five per cent of boys but only one per cent of girls often displaying physical aggression.
Boys tend to keep themselves to themselves and adopt wider interpersonal distances, and use their body language to assert dominance differently from females as described by Vigil, and men show dominance through forward-leaning postures, and approaching rapidly. Girls and women show dominance in a completely different way by tilting their heads down, using intense eye contact and smiles in accordance with their partner’s responses.
According to Kuschel, on Bellona Island in the Solomons, there is a culture based on male dominance and physical violence, and women tend to get into conflict with other women more frequently than with men. When in conflict with men, instead of using physical means, they make up mocking songs which spread across the island and humiliate their target. If a woman wants to kill a man, she will either convince her male relatives to kill him or hire an assassin. Although these two methods involve physical violence, b
oth are forms of indirect aggression, since the aggressor herself avoids getting directly involved or putting herself in immediate physical danger.
Almost the opposite of aggression is empathy, an emotion which marks a fundamental difference between the two sexes. Empathy is the ability to share others’ feelings and to take a positive interest in them, and involves the ability to decode non-verbal emotional cues, as has been well explored by Simon Baron-Cohen. Responding to other people’s emotions and sharing emotional responses are fundamental human characteristics. Proverbio and his team pointed out that, because human babies are more vulnerable than other primate infants, knowing how to interpret and respond to crying and other forms of infant communication is crucial, and has an evolutionary origin in women since it is adaptive. Infant survival will depend heavily on a mother’s responsiveness to her offspring’s visual and auditory signals.
He adds that an example of greater female empathy is their early interest in infants, which has been observed by anthropologists in virtually all human societies, whereas interactions between boys and infants are far less common. The behaviour of non-human primates strongly suggests that this early female interest in infants is a biological adaptation rather than a product of human culture and socialisation, and is supported by comparative evidence; rhesus macaques, for example, show a strong sex difference in interest in infants which persists throughout adult life.
As we have seen, girls as young as twelve months old respond more sympathetically to the distress of other people. But one study has shown that one-year-old boys preferred to watch a film of cars rather than one of people’s faces showing strong emotional expressions. By twelve months girls make more eye contact than boys, a difference partly determined by lower prenatal testosterone levels. Making eye contact in this way may be related to sociability and empathising. Female toddlers are more empathetic, showing concern for the distress of others, and heart rates in girls increase when they are told sad stories.
Adolescents aged between thirteen and sixteen years were evaluated by Simon Baron-Cohen and Sally Wheelwright for empathy, and there was a greater empathic response in girls than in boys of the same age, the difference increasing with age. In this study empathy was measured by a set of forty statements to which the subjects answered how strongly they agreed or disagreed. The sort of statements were:
I can easily tell if someone wants to enter into a conversation.
I find it hard to know what to do in a social situation.
It does not bother me too much if I am late meeting a friend.
I often find it hard to judge if something is rude or polite.
When I was a child, I enjoyed cutting up worms to see what would happen.
One may doubt the reliability of such a system of measurement but there is evidence supporting it.
Another key emotion is systemising, a natural ability to analyse data and to organise it into a coherent and logical system. Baron-Cohen’s theory is that the female brain is predominantly hard-wired for empathy, while the male brain is predominantly hard-wired for systemising, that is, for understanding and building systems. Empathising and systemising thus differ to a significant degree between the two sexes. So, for example, it has been suggested that a systemiser in our culture will probably choose magazines dealing with computers, technology and science, whereas an empathiser will choose fashion, romance and beauty. In support of these stereotypes it has been noted that psychiatric illnesses which manifest a lack of empathy, such as autism, are far more prevalent among males than among females. Many of the social differences between men and women may be influenced by these two key traits. It is essential to recognise that not all males have ‘male brains’ or all women ‘female brains’ with respect to empathy and systemising. There is much variation, and some men have ‘female brains’ and some women ‘male brains’. In general, however, the trend may be summarised as males tending to think narrowly while females think broadly. Boys born with an insensitivity to testosterone are worse at systemising, and girls born with CAH, with their high levels of testosterone during development, have enhanced systemising capability and lower empathy. The higher the levels of testosterone received by an embryo, the greater the chances of reduced empathy. A single administration of testosterone to a female embryo can lead to a significant impairment of empathy in later life.
Behavioural findings and neuroimaging support the idea of general sex-related differences in empathising in the function of the brains of men and women. Women react more strongly than men when looking at painful stimuli and are therefore more empathetic. An experiment by Proverbio involving twenty-four Italian students showed changes in the brain differed between the two sexes when shown the same pictures of humans in positive or negative contexts. The brain response to suffering humans was greater in women and resulted in increased activity in the right amygdala and right frontal area. This was observed only in women and reflects their empathy.
Testosterone affects sociability. In a 2005 study by Knickmeyer and his team carried out in England, boys and girls were compared at four years of age on the quality of their social relationships. This comparison included a popularity scale on which they were judged by how many other children wanted to play with them, and little girls won by miles. The same four-year-old children had their testosterone levels measured when they were developing as an embryo at between twelve and eighteen weeks’ gestation, at the time when their brains were being specified as male or female. Those with the lowest testosterone exposure had the best social relationships at four years old. All of these were girls, and this may be related to their capacity for empathy.
A large study of personality differences in some 10,000 subjects found key differences according to fifteen personality scales. Women scored higher on sensitivity and warmth but also on anxiety, while men got higher scores on emotional stability and vigilance, but also on aggression and dominance. The authors of the study, Del Giudice and his team, said: ‘Sensitivity differentiates people who are sensitive, aesthetic, sentimental, intuitive, and tender-minded from those who are utilitarian, objective, unsentimental and tough-minded.’
One survey in the United Kingdom found that women are more selfish than men; they are less likely to return a favour or to hand back money after seeing someone drop it, they are more likely to ignore charity workers at the front door than men, and they are more inclined to make negative remarks about their friends behind their backs. But there are also claims that men are more selfish than women.
With respect to telling lies, men are ahead. A survey commissioned by the Science Museum of London in 2010 and carried out by Onepoll asked 3,000 people about their truthfulness. According to the responses, on average, British men tell three lies every day while women, on average, tell only two. Their lies were similar in many ways, but men lied to their partners most often about their drinking habits, while women most often lied to hide their true feelings. Typical male lies were: ‘I had no [mobile] signal’, ‘No, your bottom doesn’t look big in that’, and ‘You’ve lost weight’. Female lies included: ‘Nothing’s wrong, I’m fine’, ‘I don’t know where it is, I haven’t touched it’, ‘No, I didn’t throw it away’, ‘I’ve got a headache’, and ‘It was in the sale’. Both sexes told several of the same lies, including: ‘It wasn’t that expensive’, ‘I didn’t have that much to drink’, ‘I’m on my way’ and ‘It’s just what I’ve always wanted’.
Schulte-Rüther’s team found that there are rather small differences between men and women in their ability to recognise the emotions of other people, but in women the awareness of the feelings of others is accompanied by stronger emotional resonance, while men tend to have a more cognitively driven and distant approach to the emotional states of others. Women show brain reactivity when aspects of a speaker conflict with the content of his or her message–for example, smiling when giving bad news; an effect found much less strongly in men. Women use more facial expressions than men when it comes to showing both
positive and negative emotions. The extent to which this has a biological or a social basis is far from clear, but it may be related to empathy.
There is evidence for a biological basis for women’s greater sensitivity and vulnerability to adverse and stressful events. The enhanced brain activity in women when viewing suffering humans was recorded in brain regions thought to be part of a mirror neuron system which is believed to support empathy. Mirror neurons fire both when a person carries out a particular action and also when that person sees the same action performed by someone else. There is evidence that overlapping brain activation patterns occur when this happens.
Falling in love involves, to different degrees, sexual attraction and a desire for an intimate relationship. Women are more orientated to friendship-based love, and men to game-playing love, in which they are less dependent and may be more deceptive. Falling in love lowers men’s testosterone levels, while it increases women’s, and these hormonal changes may result in a temporary reduction of sex differences in behaviour. Becoming a father has also been shown to lower men’s testosterone levels. Sexual jealousy is common, and Levy and Kelly reports that studies from around the world have found that men are, in general, more jealous of sexual infidelity than emotional infidelity, while women are more jealous of emotional cheating than sexual cheating. A possible evolutionary cause for this gender difference is that men can never be sure they are a child’s father, while women are most concerned with securing a genuinely loyal father to care for children. Women generally report greater disgust than men, especially sexual disgust. While women are more likely to suffer stress due to problems in personal relationships, men more commonly develop stress due to their work. For the most part women tend to use their emotional resources to cope and look to friends for help, whereas men tend to focus on problem-solving and taking action.
Why Can't a Man Be More Like a Woman? Page 9