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the male and female brain, revisited

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Culture does not make people. People make culture. If it is true that the full humanity of women is not our culture, then we can and must make it our culture.

Chimamanda Ngozi Adichie

An article, ‘Do women and men have different brains?’, from Mysteries of the human brain, in the New Scientist ‘Collection’ series, has persuaded me to return to this issue – or perhaps non-issue. It convincingly argues, to me, that it’s largely a non-issue, and largely due to the problem of framing.

The above-mentioned article doesn’t go much into the neurology that I described in my piece written nearly 7 years ago, but it raises points that I largely neglected. For example, in noting differences in the amygdalae, and between white and grey matter, I failed to significantly emphasise that these were averages. The differences among women in these and other statistics is greater than the differences between women and men. Perhaps more importantly, we need to question, in these studies, who the female and male subjects were. Were they randomly selected, and what does that mean? What lives did they lead? We know more now about the plasticity of the brain, and it’s likely that our neurological activity and wiring has much more to do with our focus, and what we’ve been taught or encouraged to focus on from our earliest years, than our gender. 

And this takes me back to framing. Studies designed to ‘seek out’ differences between male and female brains are in an important sense compromised from the start, as they tend to rule out the differences among men and among women due to a host of other variables. They also lead researchers to make too much of what might be quite minor statistical differences. To quote from the New Scientist article, written by Gina Rippon, author of the somewhat controversial book The gendered brain:

Revisiting the evidence suggests that women and men are more similar than they are different. In 2015, a review of more than 20,000 studies into behavioural differences, comprising data from over 12 million people, found that, overall, the differences between men and women on a wide range of characteristics such as impulsivity, cooperativeness and emotionality were vanishingly small.

What all the research seems more and more to be pointing to is that there’s no such thing as a male or a female brain, and that our brains are much more what we make of them than previously thought. Stereotyping, as the article points out, has led to ‘stereotype threat’ – the fact that we tend to conform to stereotypes if that’s what’s expected of us. And all this fuels my long-standing annoyance at the stereotyped advertising and sales directed at each gender, but especially girls and women, which, as some feminists have pointed out, has paradoxically become more crass and extreme since the advent of second-wave feminism.

And yet – there are ways of looking at ‘natural’ differences between males and females that might be enlightening. That is, are there informative neurological differences between male and female rats? Male and female wolves? Are there any such differences between male and female bonobos, and male and female chimps, that can inform us about why our two closest living relatives are so socially and behaviourally different from each other? These sorts of studies might help to isolate ‘real’, biological differences in the brains of male and female humans, as distinct from differences due to social and cultural stereotyping and reinforcement. Then again, biology is surely not destiny these days. 

Not destiny, but not entirely to be discounted. In the same New Scientist collection there’s another article, ‘The real baby brain’, which looks at a so-called condition known as ‘mummy brain’ or ‘baby brain’, a supposed mild cognitive impairment due to pregnancy. I know of at least one woman who’s sure this is real (I don’t know many people), but up until recently it has been little more than an untested meme. There is, apparently, a slight, temporary shrinkage in the brain of a woman during pregnancy, but this hasn’t been found to correlate with any behavioural changes, and some think it has to do with streamlining. In fact, as one researcher, Craig Kinsley, explained, his skepticism about the claim was raised in watching his partner handling the many new tasks of motherhood with great efficiency while still maintaining a working life. So Kinsley and his team looked at rat behaviour to see what they could find:

In his years of studying the neurobiology underlying social behaviours in rats, his animals had never shown any evidence of baby brain. Quite the opposite, actually. Although rats in the final phase of their pregnancy show a slight dip in spacial ability, after their pups are born they surpass non-mothers at remembering the location of food in complex mazes. Mother rats are also much faster at catching prey. In one study in Kinsley’s lab the non-mothers took nearly 270 seconds on average to hunt down a cricket hidden in an enclosure, whereas the mothers took just over 50 seconds.

It’s true that human mothers don’t have to negotiate physical mazes or find tasty crickets (rat mothers, unlike humans, are solely responsible for raising offspring), but it’s also clear that they, like all mammalian mothers, have to be more alert than usual to any signs and dangers when they have someone very precious and fragile to nurture and attend to. In rats, this shows up in neurological and hormonal changes – lower levels of stress hormones in the blood, and less activity in brain regions such as the amygdalae, which regulate fear and anxiety. Other hormones, such as oestradiol and oxytocin, soar to multiple times more than normal levels, priming rapid responses to sensory stimuli from offspring. Many more connections between neurons are forged in late pregnancy and its immediate aftermath.

Okay, but we’re not rats – nothing like. But how about monkeys? Owl monkeys, like most humans, share the responsibilities of child-rearing, but research has found that mothers are better at finding and gaining access to stores of food than non-mothers. Different behaviours will be reflected in different neural connections.

So, while it’s certainly worth exploring how the female brain functions during an experience unique to females, most of the time women and men engage in the same activities – working, playing, studying, socialising and so forth. Our brain processes will reflect the particular patterns of our lives, often determined at an early age, as the famous Dunedin longitudinal study has shown. Gender, and how gender is treated in the culture in which we’re embedded, is just one of many factors that will affect those processes.

References

New Scientist – The Collection, Mysteries of the human brain, 2019

https://en.wikipedia.org/wiki/Dunedin_Multidisciplinary_Health_and_Development_Study

https://ussromantics.com/2013/10/06/what-do-we-currently-know-about-the-differences-between-male-and-female-brains-in-humans/

Written by stewart henderson

June 25, 2020 at 10:50 pm