Delusions of Gender (21 page)

However, Hines has argued that this can’t be the whole answer to gender differences in toy preferences. This is because, remarkably, similar sex differences in toy preference are also seen in monkeys. In a study with Gerianne Alexander, Hines put six toys, one at a time, into a large enclosure of vervet monkeys. There were two boyish toys (a police car and a ball), two girlish toys (a doll and a pan) and two neutral toys (a picture book and a stuffed dog). They measured how long each monkey spent with each toy, as a percentage of total toy-contact time. Both male and female vervets spent about a third of the total time with the neutral toys. Male vervets spent about another third each of their total playing time with the other toys. By contrast, females spent more time with the girlish toys than with the boyish toys.
²⁶
If, by the way, you are curious about the choice of a pan as a girlish toy, you are not alone. Although it is true that primatologists regularly uncover hitherto unknown skills in our nonhuman cousins, the art of heated cuisine is not yet one of them. Frances Burton has informed me that, in her long career of observing monkeys, she has never met one that could cook.
²⁷
(This raises the more general point, spontaneously made by more than one of the academics who read this chapter, that it is not at all clear that a toy taken from human culture has the same meaning to a monkey, to which it is unfamiliar, that it does to a child.)
²⁸
It’s worth noting, then, that when the researchers divided up their stimuli in a different way – comparing amount of play with animate toys (the dog and the doll) with object toys (the pan, ball, car, and book) – they found no differences between the sexes.

After an interval of about six years, a second group of researchers ran another toy-preference study with rhesus monkeys. This study was different in two important ways. First of all, trying to get to the bottom of
why
there are gender differences in toy preference, they compared wheeled toys that invite movement with stuffed-animal toys that supposedly invite nurturing. (Whether or not the stuffed animals
were
actually nurtured is unclear, especially as one trial had to be terminated early when ‘a plush toy was
torn into multiple pieces’.) Second, the researchers gave monkeys an outright choice between the two types of toy – one of each was put into the enclosure at the same time, which is a better test of preference. They found that females were as interested in wheeled toys as they were in plush ones, and played no less with wheeled toys than did male monkeys. However, unlike females, male monkeys had a preference for wheeled toys over plush ones.
²⁹

What are we to make of the subtle sex differences seen in these two slightly contradictory studies? (Which doesn’t seem like quite large enough a number on which to base any terribly firm conclusions about human nature.) One reasonable summary might be that male and female monkeys alike enjoy playing with both stuffed toys and mobile objects, but that in males the cuddly dolls have less of a shine than the mobile toys. (Just to confuse matters, stuffed toys don’t seem to be disfavoured by either vervet males or boys.)
³⁰
What does this mean for humans, and the toys played with by little boys and girls?

These two studies have been taken as strengthening the evidence of ‘inborn influences on sex-typed toy preferences’,
³¹
support for the idea that ‘biologically based sex differences in activity preferences significantly influence sex differences in childhood object choice’,
³²
and ‘another nail in the coffin for the idea that similar preferences in human children are entirely due to culture’.
³³
Yet can we safely move to the conclusion that the higher levels of prenatal testosterone normally seen only in males increases interest in boyish toys that move or stimulate visuospatial skills, and reduces interest in toys related to babies and nurturing? These are two separate effects that are hard to disentangle when you compare interest in a moveable boyish toy
relative
to interest in a nurture-able girlish toy. Although male rhesus monkeys preferred the wheeled toys over the plush ones, because there was no gender-neutral toy condition we don’t really know whether rhesus males were especially drawn to the wheeled toys or simply
less
interested in the plush animals. After all, in the first monkey study male vervets spent no longer with the moveable ball and car than with
the neutral toys or the girlish toys. So neither monkey study does a convincing job of showing that male monkeys are born with a built-in interest in objects that move. Researchers need to get more specific about what particular feature of boyish toys supposedly appeals to the male brain, and then see whether male monkeys more than females prefer novel toys that do have this feature over other equally novel toys that don’t.

But what about the idea that females, thanks to their lower foetal-testosterone levels, are born with a greater built-in interest in toys that lend themselves to nurturing play? It’s a compelling interpretation, especially given the lack of interest in babies and dolls shown by girls with CAH. (Interestingly, they are no less interested in pets.)
³⁴
The only problem is, prenatal-testosterone levels have been found to have
no effect
on male or female rhesus monkeys’ interest in infants. Male youngsters whose mothers had been experimentally treated prenatally with an androgen-receptor blocker were no more interested in infants than control males, despite their more-feminised hormonal environment. And crucially, female youngsters whose mothers had been given testosterone injections during pregnancy were no
less
interested in infants than control females. It should be said that the researchers who reported these surprising results, seeing no evidence that mothers differentially socialised male and female infants, declared themselves ‘reluctant … to dismiss prenatal hormonal influences altogether’ in explaining sex differences in interest in infants among rhesus monkeys.
³⁵
Yet there is good reason to think that this reluctance may be misplaced.

Frances Burton has pointed out that, just like us, primate societies have norms regarding which sex does what: who gets food, rears the young, moves the troop, protects the troop and maintains group cohesion.
³⁶
But, these norms are different across, or even within, primate species. Male involvement in infant rearing, for instance, ranges from the hands-off to the intimate. For example, ‘a specially intimate relation between adult males and infants’ has been seen in some troops of wild Japanese macaque monkeys (the
species
Macaca fuscata fuscata
) during delivery season: males protect, carry and groom one-and two-year-old infants. Yet different troops of the same species, in different parts of the country, show less of this paternal care, or even none at all.
³⁷
Similarly, in another species of macaque (
Macaca sylvanus
) Burton has seen extensive and lengthy male care of young in a Gibraltar troop. Indeed, so important is male baby-sitting in this troop that ‘young females are kept away from infants so that young males may learn their role.’
³⁸
Yet among the very same species in Morocco, male care is much less significant.

As Burton argued, ‘while hormones are the same’ throughout these different species, there is ‘no universal pattern’ to how the different tasks of the society, including infant care, are divided. Sometimes both sexes perform the role, sometimes only one or the other sex does. ‘If the hormones determine the roles, one would expect to find the same sex occupying the same roles in all societies. This is patently not the case’.
³⁹
In line with this flexibility, it seems that the potential for primate male care-giving is by no means destroyed or even diminished by foetal testosterone. Another primatologist, William Mason, points out that ‘schemas for parental behaviour are present in infancy, they appear in the same form in both sexes, and they continue to be accessible throughout life.’
⁴⁰
However, interest towards infants soon begins to diverge in the sexes. At one year of age, male and female rhesus monkeys exhibit few differences in behaviour towards infants. Yet at two and three years of age, females contact, embrace, groom, touch and initiate closeness with infants more often than do males – and the females who show this greater interest in infants include females treated with prenatal androgens.
⁴¹
We may need to look elsewhere to find a reason for the lack of interest in infants and dolls in girls with CAH.

So how does a male macaque monkey in Takasakiyama, Japan, become an involved carer while his counterpart in Katuyama perfects paternal indifference?
⁴²
Perhaps the action of prenatal testosterone on the genitalia plays an important part in explaining
how primate infants come to learn the idiosyncratic traditions of their group. Monkeys take great interest in the genitalia of newborns. Unable to avail themselves of the convenience of observing whether it is a pink or blue balloon tied to the entrance of the nest, monkeys take a more direct approach to satisfying themselves as to the answer to the question that appears to be as important to them as it is to us:

In most monkey societies, the neonate is a strong attraction: all members of the troop rush over; attempt: to touch or hold it, sniff it, lick it, and otherwise exhibit interest in it. Through visual and olfactory stimuli, the sex of the individual is as much registered as its maternity.
⁴³

Is this interest in genitalia purely academic? To suggest that nonhuman primates have socially constructed gender roles seems more or less akin to pinning a notice to one’s back that says,
MOCK ME
. But does the registration of sex – of others and perhaps of self – play an important role in maintaining traditional sex-division of labour in primate societies? When Burton studied troops of macaque monkeys in Gibraltar, she observed that the head male was intimately involved in neonate care: sniffing, licking, caressing, patting, holding and chattering to it, as well as encouraging it to walk. Interestingly, when the head male was in charge of the infant, he would be followed and imitated by subadults – but only males. The male subadults then themselves became involved in caring for the infant.
⁴⁴
As we’ll see in the third part of the book, human children have a powerful drive to self-socialise into gender roles. That is, even in the absence of any encouragement by parents, they are attracted to things and behaviours associated with their sex. Although children from the age of about two have the advantage of an explicit, reportable knowledge of their own sex, is it possible that some primitive sense of sex identity brings about self-socialisation in nonhuman primates? As Hines and Alexander
recently asked, ‘if some animals of one sex could be trained to use a particular object, would others of that sex model them?’
⁴⁵

If more researchers interested in human gender differences start to investigate questions like this, which acknowledge that nonhuman primates, like us, have social norms that need to be learned, perhaps the answers will surprise us.

For many years, attention was focused on adulthood sex differences in the levels of hormones like testosterone and oestrogen. Could these circulating sex hormones, via their effect on cognition, go some way towards explaining gender inequality? Many assumed too quickly that it did. Unfortunately, as Hines concludes from her review of this research, ‘influences have been assumed to exist despite a lack of consistent supporting data.’
⁴⁶
To offer just one comical example, various studies have found that higher testosterone levels are associated with better mental rotation performance, worse mental rotation performance or equal mental rotation performance.
⁴⁷
Likewise, Steven Pinker describes this literature as ‘messy’ and ‘contradictory’ (although he nonetheless thinks that ‘something will be salvaged’ from it).
⁴⁸

And so it seems as though foetal testosterone has become the explanation of choice for gender inequality in science. In a 2005 conference on diversifying the science and engineering workforce, Lawrence Summers, then president of Harvard University, controversially suggested that women might be intrinsically less capable, on average, of high-level science. Foetal testosterone was rushed to the scene of the mishap. In the
New Republic
, Steven Pinker reminded an irrationally outraged public that variations in sex hormones, ‘especially before birth, can exaggerate or minimize the typical male and female patterns in cognition and personality.’
⁴⁹
In the
New York Times
, Simon Baron-Cohen set out a path that passes from foetal-testosterone levels, to different brains, to different cognitive talents. He also cited Connellan’s newborn study, in which
boys looked longer at a mobile, as support for Summers’s suggestion that sex differences in science-related skills are innate.
⁵⁰
And Canadian researcher Doreen Kimura wrote in the
Vancouver Sun
that Larry Summers was not mistaken in his suggestion that men and women differ in their innate talents, because sex differences ‘in levels of sex hormones early in prenatal life … strongly influence many behaviours into adulthood. Those behaviours include the intellectual or cognitive pattern, hormonal influences being especially well-documented for certain kinds of spatial ability, like being able to mentally rotate or manipulate visual objects.’
⁵¹

And yet as we’ve seen, higher foetal testosterone in nonclinical populations has not been convincingly linked with better mental rotation ability, systemising ability, mathematical ability, scientific ability or worse mind reading. Connellan’s newborn study was gravely flawed. And the research with girls with CAH and nonhuman primates – which at first glance seems to show that there are built-in sex differences in toy preferences – turns out to jumble up vague, untested ideas about what the male and female brain might be interested in with what is socially ascribed to the two sexes. One can’t help but feel a weary sense of irony in response to Pinker’s complaint that the ‘taboo’ of innate sex differences ‘needlessly puts a laudable cause [the modern women’s movement] on a collision course with the findings of science’.
⁵²
So far as I can tell, that collision has yet to occur.