D: Hormones
Writers who look to biological explanations for all sex differences tend to see hormones as having an irresistible power to mould our behaviour. Hormones are indeed what make us male or female. Information encoded in the genes begins the process of physical sex differentiation, but it is the production of testosterone and the response of cells to testosterone that turns a foetus fully male. For instance, if a boy foetus has a rare condition that means his cells do not respond to testosterone (Complete Androgen Insensitivity Syndrome), he will look exactly like a girl when he is born even though he is genetically male; testosterone is essential to make a boy a boy.
The promoters of biological explanations for sex differences are keen to establish direct links not only between hormones and physical sex differences, but also between hormones and those differences in intelligence and behaviour that they believe are innate to men and women. If those links didn’t exist, or were tenuous, then we might have to look again at the influence of society and parents and friends. I would have thought that nobody would want to deny that our personalities and our moods, as well as our physical being, are affected by the hormone environment in the womb or the levels of our sex hormones during our lifetimes. But current theories of how sex hormones act tend to gloss over all complexities. While many scientists suggest that we are only at the beginning of understanding how hormones can interact with one another and with other physical experiences, we often hear from the media and some popular writers that certain hormones simply pull the strings of our personalities. For instance, a television programme called Battle of the Sexes that aired on ABC in Australia in 2002 laid out its agenda from the start. ‘Program one presents men and women as two separate species with radically different evolutionary agendas…. The film then takes the hormone-fuelled rocket journey to puberty to show that many of the differences between the sexes are pre-programmed.’67
More than one hormone has been implicated in the creation of feminine behaviour. For a long time the spotlight was on oestrogen, and it was suggested that men who were exposed to elevated levels of oestrogens would have no choice but to fall in with feminine patterns of behaviour. There was a time when women were prescribed a synthetic oestrogen (diethylstilbestrol) in an attempt to prevent repeated spontaneous miscarriages, so studies were then carried out to find out whether this had any effect on the behaviour of the babies after birth. According to some writers, the observed effects were clearcut, as Simon Baron-Cohen explains: ‘Boys born to such women are likely to show more female-typical behaviours – enacting social themes in their play as toddlers, for example, or caring for dolls.’68
Yet such a categorical claim is not supported by much of the evidence, as Melissa Hines shows in her book Brain Gender: ‘Information on boys exposed to DES or other estrogens prenatally … suggests a general lack of influences on childhood behaviour,’ she states.69 For instance, one large study confounded the expectations of the researchers. They tested 140 adult subjects whose mothers had taken female hormones during pregnancy, asking them about their childhood play behaviour and running various cognitive and psychological tests on them. One key finding was that, ‘The DES [diethylstilbestrol] exposed subjects had the most conventionally “masculine” childhood behaviours.’70
More recently the idea has taken hold that the hormone responsible for femininity is oxytocin. Many scientists and media commentators have turned to this hormone for the explanation for women’s apparently innate abilities to empathise and nurture. For instance, both the ABC series Battle of the Sexes and a very similar BBC series Secrets of the Sexes showcased the same ‘experiment’, in which a little girl was left alone on a street to see who would stop to offer help, men or women. Women stopped far more often; which is what one would expect in a society in which to be suspected of interest in pre-pubescent girls is likely to lay men open to intense criticism. But only one explanation was offered – as the Australian series put it: ‘There is a chemical reason for empathic behaviour in women,’ the narrator told the viewers. ‘Women produce more oxytocin, which is a brain chemical stimulated by childbirth. Oxytocin is designed to help mothers nurture their offspring, and it also gives women a greater ability to empathise with others. Why do men not share this natural ability?’71 The writer John Gray has also embraced oxytocin as a catch-all explanation for feminine behaviour. As he puts it, oxytocin creates the need in women to invest a great deal of energy in loving and being loved: ‘Oxytocin creates a feeling of attachment. Levels increase when women connect with someone through friendship, sharing, caring and nurturing and decrease when a woman misses someone or experiences a loss or breakup or feels alone, ignored, rejected, unsupported, and insignificant. To feel good in a relationship, a woman needs to trust that her partner cares for her as much as she cares for him. This kind of support directly affects her oxtyocin levels, which in turn will lower her stress. Messages from him of caring, understanding, and respect can build trust and nourish her soul while stimulating higher levels of oxytocin.’72
Oxytocin is indeed released during childbirth and during breastfeeding, when it stimulates the contractions of the womb and the let-down reflex of breasts, and for both sexes it seems to be released at orgasm. At these times it certainly does correlate to the moving sense of being connected and in love with another being. There has also been interesting research carried out which suggests that if individuals’ levels of oxytocin are artificially raised they may be more ready to behave in a trusting manner. But if you search for the evidence to prove that higher levels of oxytocin are behind women’s greater investment in their social and family lives, you will be a long time looking. Most research on oxytocin has been carried out on other animals, especially rodents, and one recent review of all the human and animal studies on the effects of oxytocin could only conclude that the evidence for the influence of oxytocin on human behaviour seemed ‘contradictory’ and open to ‘competing’ interpretations.73
At times elevated levels of this hormone correlate with loving and unstressed behaviour in humans, but at times they correlate with the opposite. For instance, when scientists at the University of California investigated the relationship between older women’s social networks and their oxytocin levels, they found the opposite result to the one that the popular narrative would predict. Oxytocin was actually higher in women experiencing chronic problems in their social relationships, including ‘decreased contact with friends and family and an unrewarding partner relationship’.74 These researchers had to conclude that far from being John Gray’s straightforward hormone of love and understanding, ‘Oxytocin levels may be a marker of relationship stress.’75 Similarly confusing for the idea that oxytocin is behind women’s feminine, empathetic behaviour was a recent study which found that when couples kissed, oxytocin levels went up for men, but down for women; which was in the opposite direction to that predicted by the theory that women look for love in order to boost their oxytocin levels.76
It is often assumed that typical femininity is created not just by the presence of some magical pink elixir, but also by the absence of a magical blue elixir. As we all know, the hormone testosterone is thought to create the mythical masculinity of aggression and competitiveness, and women’s low levels of testosterone are often assumed to lie behind their poor showing in masculine traits. That BBC1 series Secrets of the Sexes presented the idea that men are innately better at logical thinking and competing because of their testosterone, and in a driving competition in which men did better than women the voiceover intoned: ‘Women can be competitive, but they don’t have the edge that testosterone gives men.’77 There is nothing new about the reliance on testosterone as the explanation for everything we associate with masculinity. Connections have been made between testosterone and all kinds of power-hungry, aggressive, competing behaviour everywhere in the media, in fiction, non-fiction, journalism and broadcasting. As one typical commentator in The Times put it, ‘My sons charging around, competing, building, cli
mbing and fighting, are run on that human rocket fuel, testosterone.’78 Testosterone has been implicated in men’s greater reliance on logic, on their supposedly greater sense of humour,79 apparently greater artistic abilities, and perceived advantage in systemising and spatial skills.80
To find evidence for this picture of the effects of testosterone, scientists over the years have been particularly interested in those people who were exposed to high levels of testosterone as foetuses. In the rare condition called Congenital Adrenal Hyperplasia, foetuses, male or female, are exposed to excessive levels of testosterone in the womb. We know what many writers would assume would be the results of this deluge of testosterone for girls: they will lose their femininity and become more aggressive, less empathetic, and better at systemising. Many writers would also assume that it means they would have better spatial skills, so Simon Baron-Cohen tells us: ‘As one would predict, girls with CAH have enhanced spatial systemising, compared with their sisters or other close female relatives without CAH … Girls with CAH score as well as normal boys, and dramatically better than normal girls.’81 Helena Cronin, the Darwinian philosopher, writes in the Guardian: ‘females exposed to “male” hormones in the womb are typically “tomboyish” and surpass the female average in spatial skills – and vice versa for males’.82 Steven Pinker in The Blank Slate says that girls with CAH ‘grow into tomboys, with more rough and tumble play, a greater interest in trucks than dolls, better spatial abilities.’83 Susan Pinker, in The Sexual Paradox, says, ‘They have better spatial skills and are more competitive, aggressive, and self-confident than other girls.’84 [My italics all through.] However, if you look at the evidence, this has simply not been proved. Melissa Hines analysed all the available studies in her book Brain Gender, and found that of seven studies assessing spatial abilities in females with CAH, only three found evidence that females with CAH perform better than unaffected females, and the largest studies showed no such result – indeed, the study with the second largest sample found that females with CAH performed worse than matched female controls.85
Similarly unpredictable results are seen throughout the literature on the effects of testosterone. Far from bringing us a clearcut story of how testosterone sets up stereotypical masculinity, we find a very muddled picture about how this hormone affects behaviour. Some studies go in the right direction for the biological narrative. For instance, Simon Baron-Cohen’s team at Cambridge University tested samples of amniotic fluid from women who had given birth at Addenbrooke’s Hospital and then observed their babies as toddlers. They found that toddlers who had been identified as having been exposed to less testosterone in the womb had ‘higher levels of eye contact and a larger vocabulary’.86 Other studies have also shown a relationship between pre-natal testosterone and whether children will fall in with stereotypical masculine behaviour. For instance, one large recent study has suggested that high levels of testosterone in the womb correlate with masculine play behaviour for girls.87
These are two studies that do show a role for testosterone in creating masculinity along the expected lines, and you can find others.88 But as I trawled through some of the literature I found there is also a lot of research that has failed to reinforce the expected narrative, and that gives us a much more complicated picture of the effects of testosterone in the womb.
For instance, a Canadian psychologist, Jo-Anne Finegan, measured testosterone in amniotic fluid and outcomes in children at the age of four years. She found that for the girls in the study, the more testosterone they were exposed to, the worse they were at counting and sorting, number questions, and block building. That result is in the opposite direction to the one you would expect if you assumed a link between testosterone and systemising skills. She also found that there was a relationship between higher levels of testosterone in girls and higher language comprehension, which was also against the direction predicted. For the boys in the study, no relationships were found.89 When four Dutch psychologists set out to test whether higher prenatal testosterone was associated with more masculine play behaviour in toddlers, they found no significant relationship between maternal sex-hormone levels and masculine or feminine play behaviour in either boys or girls. The only correlation those psychologists found was between progesterone and masculine play for boys, which was hardly predicted.90
There is much other evidence on the record that shows how the predicted relationships between testosterone and masculinity have been hard to find.91 When I looked through the studies that fall on one side and those that fall on the other I could not judge which of them were right, as obviously I am not qualified to do that, but I could see, very clearly indeed, that the consensus some commentators assume is there does not, in fact, exist. Where consensus does exist in the academy about testosterone, it often works against the traditional narrative. One of the links that is always made most strongly in the popular imagination is, of course, the link between testosterone and aggression. The reason why women are so much more cooperative and gentler than men, it is thought, is simply because they don’t get the necessary injection of testosterone. In animals, the relationship is very clear. Melissa Hines, who started her career more than thirty years ago by looking at aggression and the correlation with testosterone, laughs when she says how simple it is in rats. ‘If you give rats more testosterone they become more aggressive; take it away and they become less aggressive. But in humans? People have been trying to find the same pattern in humans for years. But it’s much, much harder to find. We do have to ask if it’s really there.’
What we may think is evidence of the effects of testosterone may in fact be evidence of the effects of social expectations. Take this famous Californian experiment as an example. It was a double-blind experiment – an experiment in which neither the subjects nor the administrators know who is receiving the real drug – in which forty-three healthy men were given either a high dose of testosterone or a placebo for ten weeks. Those who received testosterone, but did not know it, did not experience increased anger, according to self-reports, and ratings by observers including parents and spouses suggested no changes in angry or aggressive moods or behaviour. On the other hand, in a second study those men given a placebo and told it was testosterone did report greater anger, irritation and impulsivity. This shows that when we are talking about what we think are the results of men’s higher testosterone we may be talking about something else altogether.92
Our belief that there must be a direct, one-way link between hormones and typically masculine behaviour may blind us to the part that social expectations play in keeping women and men within stereotyped roles. I was very taken by the description of one intriguing study, which seemed to dramatise the way that women mask their own aggressiveness – even from themselves. Two Princeton psychologists asked eighty-four men and women to play a video game in which they would be bombed by an opponent and then would have the chance to bomb that opponent. Half the study participants were told that their identities were known to the researchers; the other half were told they were anonymous. What was so interesting was that women became as aggressive as men when they thought they were anonymous, but held back when they thought they were being watched. What’s more, when, after the game, participants were asked to describe their own aggressiveness and the number of bombs they dropped, the men accurately described themselves as aggressive. But the women reported that they had behaved less aggressively than they really had. The failure of women’s self-reports to reflect their own high levels of aggression in the anonymous condition was striking, given the evidence that they were at least as aggressive as males. The researchers concluded, ‘We consider the findings to be evidence that people do not accurately perceive their own behaviour, but instead assume it to be in accordance with established norms and expectations.’93
Such research alerts us to the possibility that even though we are so eager to look for biological reasons behind masculine and feminine behaviour, other factors could be equally, if not more, important
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E: Brains
Alongside the theory that the differences in feminine and masculine behaviour are produced by the action of certain hormones, is the theory that the proof that we are destined for such different roles can be seen in physical differences in men’s and women’s brains. This theory has really taken off in this generation, since recently developed techniques such as positron emission tomography and functional magnetic resonance imaging make it possible to look into the workings of the living brain, and these techniques have spawned much research that shows differences between male and female brains. Month after month, broadcast media and broadsheet and tabloid newspapers make excited statements such as: ‘Do men really listen with just half a brain? Research sheds some light’94 or ‘Men may as well be from Mars and women from Venus for all the sexes have in common emotionally; brain scans showed major differences in the ways in which men and women responded to emotional stimuli.’95
One of the most commonly expressed ideas about men’s and women’s brains is that women use the left brain more, and men use the right brain more, and that the right hemisphere processes space and systems while the left processes words and emotions. As one commentator in The Times put it when writing about her sons, ‘With their greater muscle bulk and right-brain development, they are less likely to sit around threading beads, making subtle, nuanced, left-brainy conversation [my italics].’96 Neuroscientists over the years have examined whether this difference can be seen in a physically larger right hemisphere in men’s brains. And much of the media have now assumed that this is the case, so a recent study of the relative sizes of brain hemispheres among gay and straight men and women was reported as though there was a simple consensus that straight men’s brains show greater rightward asymmetry. ‘Scans reveal homosexual men and heterosexual women have symmetrical brains, with the right and left hemispheres almost exactly the same size. Conversely, lesbians and straight men have asymmetrical brains, with the right hemisphere significantly larger than the left,’ was how this study was reported in the Guardian in a huge and lavishly illustrated article.97
Living Dolls: The Return of Sexism Page 19
