Posts Tagged ‘sex differences’
on gender, and bonobos
So there seems to be a lot of noise about gender issues these days, and it has been a topic of much interest to me from pre-pubescent days. I wrote in my novel In Elizabeth about how, even in primary school, I stood at the back of my class line during ‘school assembly’ and surveyed my classmates in terms of ‘likeability’, not so much in sexual terms, though there was probably an element of that. It interested me to think, or feel, that those who attracted me least were the ‘girly girls’ and ‘the boysy boys’, even if I could only judge from the clothes they wore, which may well have been chosen by their parents. But also something in the way they moved, which attracted or repulsed me like no other school-kid.
Later, into my teens, with schooldays happily left behind, I discovered Bowie, and Lou Reed’s Transformer album, and played deliciously transgressive games with lipstick and stockings and a tucked-away penis. It was a phase, you might say, but I do recall that in the pre-pubescent era, I found boys who were just as physically attractive as girls, an attraction that faded with the appearance of facial hair and signs of muscularity. Broken voices might have broken the spell too.
One term that I never had to consider, of course, was the term ‘trans’, a term I’m still not sure that I understand, hence this investigative piece. But before I embark on that prickly issue, here’s a thought.
Do dogs know that they’re male or female? Cats? Birds? Yes, some get pregnant, or lay eggs, while other don’t, and that’s how we distinguish them, as well as anatomically, but… Is it a matter of consciousness, aka the hard problem of philosophy? Of course ‘AI’ provides an answer, which is more or less the one I would give. Gender as we know it is a social construct, as well as an aspect of language, but with other creatures it’s more about biological cues – pheromones perhaps, as well as subtle physiological differences (perhaps not so subtle for them). Chimps/bonobos seem to recognise those of their own sex, not just for sex but for hanging out, for fighting and so on. And it seems that, even with our close cousins, there are girly girls and boysy boys, as Frans de Waal noted in his book Different, particularly in his description of the gender-nonconforming female chimp, Donna, brought up in the Yerkes Field Station in Atlanta, USA:
Donna grew up into a robust female who acted more masculine than other females. She had the large head with the rough-hewn facial features of males, and sturdy hands and feet. She could sit poised like a male. If she raised her hair, which she did more often the older she got, she was quite intimidating, thanks to her broad shoulders. Her genitals were those of a female, however, even though they were never fully swollen. Female chimpanzees, at the peak of their thirty-five day menstrual cycle, sport inflated genitals. But after Donna passed puberty, hers never reached the shiny maximum size that announces fertility. The males were barely interested in her and refrained from mating. Since Donna also never masturbated, she probably didn’t have a strong sex drive. She never had offspring.
Frans de Waal, Different: what apes can teach us about gender, pp 50-51
de Waal spends the next half dozen pages describing Donna in terms of sex (physical elements) and gender (behaviour), which again reminds me of schooldays. Donna was big for a female, just as some human females are taller and heavier than the average male, her calling voice was lower than most females’, and she engaged in hooting, swaggering behaviour with other males, though she was never violent. As with humans, male chimps are hairier than the females, but Donna was hairier than most. In spite of her eccentricity, her tendency to hang out with the males and her unusual appearance, she was well-accepted by her troupe.
So was Donna “trans”? de Waal asks this question himself:
Individuals who are born as one sex yet feel they belong to the opposite sex are known as transgender. Transgender humans actually prefer to turn this description around and prioritise their felt identity. They were born as one sex but found themselves inside the body of the other. We have no way of applying this to Donna, however, because we can’t know how she perceived her gender. In many ways – her grooming relations with others, her non-aggressiveness -she acted more like a female than a male. The best way to describe her is perhaps as a largely asexual gender-non-conforming individual.
Ibid, p54
I mentioned schooldays. A fond memory from when I was around nine years old was of a class-mate, a big strapping thunder-thighed girl who would lie on her back on the school’s grassy knoll and urge us to run and jump on her. She’d catch us, rough us up a bit, then toss us to one side ready for the next victim. As the smallest kid in the class I was an easy toss, and I loved it. I found her totally admirable, perhaps also because she was the smartest kid in my class – along with myself of course.
The point here, I think, is acceptance of difference – which is what de Waal’s Different is all about. In some ways the ‘trans’ thing is about our need to categorise, and our obsession with being hard and fast about those categories. I recall my enthusiasm when unisex toilets became a thing a couple of decades ago, but it doesn’t seem to have caught on, really, though I do know of a few people who subscribe to gender fluidity, and ‘men who want to be men’ and ‘women who want to be women’, are types I prefer to avoid, largely because they tend to want to impose those hard and fast categories on others. But in researching ‘gender fluidity’ I again find this human tendency to categorise gets in the way, with ‘gender fluid’ being described as it own category that requires explaining, like some medical/physiological/psychological condition, as if people who are this way worry about being abnormal in some sense, rather than rarely giving it a moment’s thought.
And yet, what with the patriarchy that is still with us, abetted by all the major religions, gender in a general sense is something we need to face. So I will leave transgender and gender reassignment issues, which are purely human ones, for another piece, and focus for now on sex, or gender, and power, which is an issue for all complex social creatures.
de Waal has a chapter in his book, ‘Bonobo Sisterhood’, which compares those apes with their chimp cousins and neighbours. The Lola ya Bonobo sanctuary near Kinshasa, capital of the embattled Democratic Republic of the Congo (DRC), is home to over 70 bonobos, many of them damaged orphans rescued from poachers and traders. This has made the sanctuary a difficult place for observing the natural life of bonobos, since many of them have experienced injury, separation from parents and other disruptions, including leading pampered lives in human households. One female bonobo who had been brought up with humans was quite bewildered when brought to the sanctuary, where other females greeted her with kisses and presenting of genitals for hoka-hoka, also known as genito-genital (GG) rubbing, a form of female sexual bonding that is key to their collective control of males. Not having been brought up in a bonobo environment, this female took some time to become accustomed to the ‘natural’ behaviour of her kind. Another bonobo had spent his early years in a gorilla enclosure, and was accustomed to making ‘gorilla’ noises and gestures. He was quite bewildered when female bonobos made advances, and didn’t recognise their genital swellings as anything sexual – though he eventually worked it out.
The point here is that there are social cues about sex and behaviour as well as what we might consider natural cues. And, as Donna the chimp has shown us, there may be wide differences in sexual behaviour within species, and it might be well for we humans to note the tolerance within the chimp community shown to Donna’s quasi-male behavioural traits.
de Waal provides a description of bonobos, particularly in contrast to chimps, that I’ll set down here to remind myself, more than anyone, of the difference:
Chimps look as if they work out in the gym every day. They have large heads, thick necks, and broad, muscular shoulders. In comparison, bonobos have an intellectual look, as if they spend time in the library. They have slim upper bodies, narrow shoulders, thin necks, and elegant piano-player hands. A lot of their weight is in their legs, which are long and thin. When a chimpanzee knuckle-walks on all fours, his back slopes down from his powerful shoulders. A bonobo, in contrast, has a perfectly horizontal back because of his elevated hips. When standing on two legs, bonobos straighten their back and hips better than any other ape, so that they look eerily human-like. They walk upright with remarkable ease while carrying food or looking out over tall grass.
Frans de Waal, Different: p 109
There’s more, and you get the impression that de Waal is very much captivated by the species. He even argues that their anatomy is closer to Lucy, our Australopithecus ancestor, than is any other of the great apes. It’s true that they’re more arboreal, due to the environment in which they’re confined. They’re also more group-oriented than chimps and more neotenous, according to de Waal. That’s to say, they preserve childhood or juvenile traits into adulthood – as do humans, with our love of play of all kinds. Their sensitivity may be attested to by a poignant story related by de Waal. A group of bonobos were sent to the Hellabrunn Zoo in Munich in the 1930s, just around the time that they were recognised as a separate species. Their uniqueness was noted by the first experts who studied them – ‘The bonobo is an extraordinarily sensitive, gentle creature, far removed from the demoniacal Urkraft [primitive force] of the adult chimpanzee”. But, as de Waal relates:
Sadly, the Hellabrunn bonobos died on the night in 1944 when the World War II allies bombed Munich. Terrified by the noise, they all succumbed to heart failure. That none of the zoo’s other apes suffered the same fate attests to the bonobo’s exceptional sensitivity.
Ibid: p 111
It seems to me – no doubt many would disagree – that bonobo sensitivity bears some relation to their matriarchal and more generally bonding culture. As de Waal and others point out, bonobos really are very very sexual, and it has nothing to do with reproduction, the rate of which is no greater than chimps. And it really is a ‘make love not war’ mind-set, with sexual closeness, especially among females, acting against serious violence, though they can be as rough-and-tumble in their play as their chimp cousins. de Waal, in his bonobo chapter, describes how reluctant the scientific community were to accept both bonobo matriarchy and bonobo sexual enthusiasm. I find this community’s reluctance, even today, to emphasise the matriarchy and sexuality of this closest relative of ours, to be a source of great frustration. Bonobos deserve our attention – and will repay it in spades – not just by the fact that they’re matriarchal but in the way they’ve become matriarchal, in spite of a slight sexual dimorphism in the males’ favour. Diane Rosenfeld’s The Bonobo Sisterhood is a start, but it requires the attention and activity of both females and males to move us in the right direction. Et ça va prendre beaucoup de temps, malheureusement.
References
Frans de Waal, Different: what apes can teach us about gender, 2022
Diane Rosenfeld, The bonobo sisterhood, 2022
https://www.bonobosisterhoodalliance.org
what’s on my mind, and in my brain?
The mind is certainly a very mysterious organ, I reflected,.. about which nothing whatever is known, though we depend upon it so completely.
Virginia Woolf, A room of one’s own, 1928
ah yes, it all makes sense now…
So there’s still plenty to learn about the mind, and maybe calling it the brain is only giving us a false sense of the matter (and I’m thinking of ye olde ‘what’s mind, it doesn’t matter, what’s matter, never mind’ jibe), though we’ve made great neurophysiological strides in recent decades. But having just read Virginia Woolf’s thoughts on the position of women almost a century ago, and being old enough to remember texts like ‘Women are from Venus, men are from Mars’, which sought to ‘explain’ and make the best of the pigeonholes the author presumably believed in, I’ve decided to have another quick look at the current expert views on the neurophysiological and hormonal differences between the sexes.
What I’ve found is that it’s still a contested issue. When I last reported on it, I found myself very happy to accept that there are statistical differences between male and female brains, but no categorical differences. That’s to say, both male and female brains vary widely, and it’s reasonable to say that the differences within each gender are as great as the differences between them. Another striking way to think about it is to say that, were you to hand a still living but completely disembodied human brain (just imagine!) to a trained and experienced neurologist, they’d be unable to say categorically that it was M or F.
Well, the first website I’ve come to disputes this claim. It’s from PNAS (often fondly vocalised as ‘penis’, which may or may not be relevant) and it’s a short essay with only one author, Marek Glezerman. My initial sense of it is that he misses the point, and seems disturbingly emphatic. To give an obvious example, the title of the piece is “Yes, there is a female and a male brain: Morphology versus functionality”. In his opening paragraph (but the essay only has two paragraphs), Glezerman summarises the conclusion he disagrees with, a conclusion I based my own essay on years ago:
The authors conclude that brains of women and men are not dimorphic and not categorically different, as are the genital systems of the two genders, but resemble more an overlapping mosaic of specific functional regions and therefore cannot be distinguished as male and female brains.
Reading this made me wonder, and I thought back to the night before – ahhh, the night before – when I spent time at a well-frequented pub full of individuals, male and female, well beyond the first flush of youth. It occurred to me that there wasn’t a single person there whose sex I would feel mistaken about. Many of the men, and none of the women, were balding, bearded and paunchy. Some did have breasts, I admit, that could’ve competed with the females, but I doubt if they’d have managed the same expression, so to speak. And though there was a lot of variety in the voices, it was easy enough to distinguish males from females in that characteristic. Of course there were also differences in dress, mannerisms and choice of drink, but those could be put down to ‘culture’ and dismissed. Even so there might be enough evidence on display to suggest a categorical difference – a morphological difference – traceable to the brain and hormones.
So, what did Glezerman mean, exactly, by ‘morphology versus functionality’? Well, here’s a long, but essential quote from his essay.
Whenever the terms “female brain” and “male brain” are used, the intention should be functional and not morphological, qualitative and not quantitative. Functionally, brains of women and men are indeed different. Not better, not worse, neither more nor less sophisticated, just different. The very brain cells differ chromosomally. The male brain is exposed to a completely different hormonal environment during intrauterine life than the female brain. The available scientific data as to the crucial effect of testosterone on the developing male brain is overwhelming.
Glezerman provides references for his claim about testosterone and its effects, a subject of great interest to me, but I’ll leave that for another essay. But one wonders if this isn’t a storm in a teacup. Going back to my pub reference, of course there were differences within the sexes – some males seemed more ‘feminine’ than others, whatever that may mean, and some women more ‘masculine’. This may again be a matter of hormone expression rather than personal choice, or a complex combination. I find it fascinating that male hormone levels (i.e testosterone) are dropping in the WEIRD world, a matter of concern to some, but not me…. oh, but that’s for that other essay, or did I already write that one?
PNAS has a reply to Glezerman’s essay, which I’ll now focus on. And I should note how polite and civilised these scientific disputes are: far from the world of social media. This response is even shorter that Glezerman’s little essay (I’ll bet that was by design!), so I’ll reflect on it here, passage by passage.
As Marek Glezerman (1) rightly points out, there are differences between females and males in brain and behavior. Glezerman overlooks, however, the fact that such differences may be different and even opposite under different environmental conditions. That is, what is typical under some conditions in a brain composed of cells with an XX chromosomal complement residing in a body with low levels of testosterone, may be typical under other conditions in a brain composed of cells with an XY chromosomal complement residing in a body with high levels of testosterone.
Being a person who spreads himself thinly over a wide variety of intellectual topics (i.e master of none), I had to look up XX and XY (remember mate, two kisses female, one kiss male – which is surely typical). What the response (which has three authors) appears to be saying is that what is typical for a low-testosterone female in some conditions, may also be typical for a high-testosterone male under quite different conditions, in spite of the fact that one set of brain cells carries an XY chromosomal complement, while the other carries XX. Not sure if this carries the day though. But to continue:
Such “reversals” of sex effects have also been reported when the manipulation of environmental conditions was done in utero (by manipulating the dam) and the offspring were tested in adulthood (reviewed in refs. 2 and 3). These observations led to the hypothesis that brains are composed of a “mosaic” of “male” and “female” features rather than of only “male” features or only “female” features, as expected of a “male brain” and a “female brain,” respectively (2, 3)
Wasn’t sure what ‘manipulating the dam’ meant, but a dam is a dam, something that reduces or stops flow, so I suppose this was done in non-human test species? Presumably if you’re able to change hormonal conditions in utero via such methods – or by changing environmental/social conditions, as bonobos appear to have done – you will change the mosaic of behaviour. Bonobos can be quite aggressive, but it appears to be more tilted towards the male of the species. Also, the drop in male testosterone is surely due to changed conditions and expectations for males over a relatively short period – for example in the mere century since A room of one’s own was written, but even more so in the past few decades of mechanisation and anti-machismo, at least in the WEIRD world.
Our study (4) is the first to empirically test whether brains are “male” or “female” by assessing internal consistency in the degree of “maleness-femaleness” of different elements within a single brain. We found that brains with both “female-end” and “male-end” characteristics were more prevalent than brains with only “female-end” or only “male-end” characteristics. This was true for both the volume of brain regions and the strength of connections between regions (assessed in a similar way to ref. 5), in contrast to Glezerman’s assumption that “Other imaging methods might have yielded different results.”
This is claiming evidence for mosaic traits in a majority of the brains under study, both for individual regions in isolation and for brain connectivity. All I can say is that this seems eminently plausible, indeed I would’ve expected such a finding. Not sure, of course, what ‘male-end’ and ‘female-end’ characteristics are exactly. There is a question here, though, about what Glezerman meant by ‘other imaging methods’.
To corroborate our analysis of different aspects of brain structure assessed using MRI, we also analyzed brain function, as revealed in people’s behaviors, personality characteristics, preferences, and attitudes. Also here there were many more people with both “feminine” (i.e., more common in females compared with males) and “masculine” (i.e., more common in males compared with females) characteristics than people with only feminine or only masculine characteristics (4).
Behaviour, over time, can affect brain function and brain regions mightily. An obvious case is language, spoken and written, which is a behaviour that has had considerably impact on the brain, as, for example Maryanne Wolf recounts in Proust and the squid. You’d hardly expect those brain regions that have been adapted/co-opted for language production/reception to have been much affected by gender. The same would go for other skills and practices, such as mathematics. As to the different physical characteristics of males and females (my pub observations), how connected are they to our brains? They certainly have much to do with hormones, of which we have at least fifty types, many of which are connected to/stimulated into action by the pituitary gland, which is in turn stimulated by the hypothalamus, but these regions account for a minuscule proportion of the brain.
There is no doubt that sex affects the structure and function of brain cells. However, the fact that sex can affect brain cells does not necessarily entail that the form and function of brain cells are either “male” or “female” nor that the brains comprised of these cells can be divided into two distinct categories. For such claims to be true it is necessary that the effects of sex are dimorphic, resulting in the formation of distinct “male” and “female” types, as well as internally consistent (2, 3, 6).
I think what’s being said here is that just because our brain cells, indeed all our somatic cells, have either an XX or XY chromosomal complement in their nuclei, this doesn’t dictate essential expressed traits – our intelligence, our humour, our physical skills, our bodily needs, and so forth. As this essay suggests, ‘manipulating the dam’ in utero is likely to have a far greater effect on human development than gender does, unless of course you’re born into a culture in which one gender is significantly undervalued. But let’s not go too near that hornet’s nest.
So to the last lines of the reply to Glezerman:
Hopefully, future studies looking at the relations between sex and other systems in which sex differences have been documented (e.g., the immune system, the cardiovascular system) will assess both internal consistency and degree of overlap, to reveal whether the relations between sex and other systems are more similar to the relations between sex and the brain (mosaicism) or to the relations between sex and the genitalia (dimorphism).
And no doubt there will be differences, especially in relation to hormonal levels associated with the reproductive system, but also in those associated with diabetes, the heart and the circulatory system and so forth, but these are not easily predictable based solely on gender. And there’s another problem with fixating on sex differences in a hard and fast way. It’s not exactly coincidental that male supremacists are all for favouring such differences. That’s why the bonobo example needs to be known and promoted far more than is currently the case.
References
https://www.pnas.org/doi/10.1073/pnas.1600791113#core-r2
What do we currently know about the differences between male and female brains in humans?
the male and female brain, revisited