The real life situations that prove gender-based science is right

men vs women science
There are many phenomena – throughout the body and the brain – that set the sexes apart from each other, writes neuroscientist David Cox

The assertion that men are from Mars and women from Venus has long been derided as a trivialisation of complex biology. Scientists have argued for decades over whether the well-known stereotypes of men being bad at multitasking, and women being more nurturing and better communicators, reflect innate biology or if they’re more a consequence of social norms and expectations.

But in recent years, various studies have begun to tease apart some subtle and previously little understood variations between the sexes, both within our psyche and physiological makeup. They could finally help to explain some of the differences in our behaviour, but also our vulnerability to different illnesses and the fact that women have a greater life expectancy – statistics have shown that on average, women around the world outlive men by at least five years.

This week, a new paper from neuroscientists at Stanford University, published in the journal PNAS, has found differing levels of activity in parts of so-called social brain regions, when comparing MRI scans of men and women. Female brain scans indicated higher activity in the default mode network and the limbic system, brain networks that are involved in introspection and processing thoughts, feelings and emotions.

Prof Melissa Hines, the director of the Gender Development Research Centre at the University of Cambridge, says that this study points towards behavioural differences between the sexes that we’ve known about for some time.

“On average, groups of men and women differ behaviourally, not in general intelligence, but in smaller differences like spatial thinking or the ability to detect emotion in faces” she says. “And so you would assume those differences are present on average in brains of males and females.”

But the inner workings of the mind is just one of the many ways in which men and women are biologically different.  As London-based GP Dr Ziad Tukmachi points out, perhaps the most obvious difference between men and women is the reproductive organs. But genitalia aside, it is the internal reproductive organs which comprise some of the starkest differences between the sexes.

“Men have a prostate and women don’t,” says Dr Tukmachi. “The prostate gland is used for sexual function and creating semen, whereas women have ovaries for releasing eggs, and therefore the womb sheds a lining every month to allow for a period. So that’s a huge biological difference between the two.”

Later in life, this plays out in disease risk with prostate cancer being one of the most common conditions in men above the age of 50, while post-menopausal women become more vulnerable to cancers of the womb and ovaries. But aside from the ones that we’re largely aware of, there are other intriguing biological differences to consider. Many of which have a considerable impact on our respective lives.

The workings of the brain

men vs women science
'Women are more than twice as likely than men to develop depression and far more likely to develop eating disorders,' writes Cox

Women have long been known for more inward and considered thinking than men, something illustrated by the new study. Previous research has shown women on average to be more empathetic and perceptive as to the thoughts and feelings of others, as well as more compromising in personal and professional relationships.

But this can also be a disadvantage and predispose women to higher rates of mental illness, as they can become trapped in patterns of damaging internal thoughts. Women are more than twice as likely than men to develop depression and far more likely to develop eating disorders, and new therapies including psychedelics like psilocybin attempt to tackle this by disrupting the activity of the default mode network.

However, Prof Hines says we still need to understand more about whether these brain patterns occur naturally in men and women, or whether they have arisen due to social expectations. “You could be socialised to be more empathic, and your brain would be different,” she says. “Just because these differences are there, doesn’t tell us anything about where they came from.

Bigger heart and lungs

men vs women science
Changes during puberty result in different lung and heart sizes

Men also tend to have larger hearts and greater lung volumes than women, which is why male athletes have a higher oxygen capacity. This is related to changes which occur during puberty.

“Because men tend to have a naturally greater muscle mass than women, certain organs that contain muscles, such as the heart, also tend to be a little bit bigger,” says Dr Tukmachi.

Because they are slightly smaller, women’s hearts must also beat faster to pump the same amount of blood. This means that they are more sensitive to the impact of stress and it makes smoking a greater risk for heart disease in women than men, according to the Mayo Clinic.

Building muscle

men vs women science
Men have more fast-twitch muscle fibres, whereas women have more slow-twitch muscle fibres

The onset of puberty releases a surge in the levels of the hormone testosterone which leaves adult men with a higher muscle mass on average than women, particularly in the upper body.

Men tend to convert a greater amount of their caloric intake into muscle, meaning that their individual muscle fibres are larger than women’s. However, in recent years studies of male and female athletes have indicated that the types of muscle fibres men and women accumulate are quite different.

For example, while men have more fast-twitch muscle fibres designed for power and speed, women seem to have a higher number of slower-twitch fibres. This makes them more naturally tuned for activities which require endurance, for example distance running, swimming and cycling.

While men still outperform women in many elite sports due to their power advantage and greater oxygen capacity, their advantage diminishes as endurance takes on greater importance. As an example, in extreme endurance sports such as ultra-marathons, the playing field between the genders is much more even.

Storing fat

men vs women science
Women's and men's bodies have different distributions of fat

Women generally have a much higher percentage of body fat compared to men, as well as storing it in different areas. Men tend to store fat in the abdominal areas, while women’s bodies accumulate fat around the hips and upper thighs.

However, because men are designed to carry less fat, they are far more impacted by changes related to fat accumulation which then impacts their hormones. “Fatty tissue around the tummy can convert testosterone to oestrogen,” says Dr Ma’en Al-Mrayat, an endocrinologist at University Hospital Southampton NHS Foundation Trust. “So men who put on weight in middle-age and later life find themselves with an imbalance of these hormones which can affect sexual function and the ability to get erections.”

Changing vocal cords

men vs women science
Men are two to three times more likely to develop sleep apnea due to the structure of their airways

Men have far thicker vocal cords than women, up to 25mm in length while female vocal cords are only between 12.5 and 17.5mm. This impacts the pitch of the voice and is why adult male voices are usually deeper.

However men also have far larger upper airways, which makes them twice as likely to be noisy sleepers in comparison to women. This is because the space at the back of their throats is much greater for amplifying snores.

The structure of men’s airways also mean they are two to three times more likely to develop sleep apnea where they stop breathing entirely for a few seconds at a time during sleep. Prof Guy Leschziner, an expert in neurology and sleep medicine at King’s College London, says that this in turn increases risk of various chronic illnesses because it actively disrupts sleep.

“Sleep seems to have a very important function in regulating how our brains work, and if you’re disrupting your sleep as a result of these obstructive events, that may put you at increased risk of conditions like dementia,” he says.

Strong bones

men vs women science
Higher testosterone levels mean denser and stronger bones, tendons and ligaments in men

In general, men have far denser and stronger bones, tendons and ligaments, because of higher testosterone levels. For women, the effect of oestrogen is to improve the levels of minerals within their bones but once they go through menopause, they experience a rapid loss of bone mass within five years due to declining oestrogen levels.

Men also lose bone mass as a result of ageing, but this effect tends to be delayed and occurs more after the age of 70, which is why women are more prone overall to fractures and osteoporosis.

Hormone levels

men vs women science
Varying hormone releases and concentrations cause differing social behaviours, and vulnerability to diseases, between the sexes

At the same time, the variations in male and female hormone levels can also dictate vulnerability to different organ diseases. Men tend to develop heart disease far earlier than women, which is thought to be caused by the fact women have higher levels of oestrogen and progesterone: both of which have a protective effect on the heart until they pass through menopause.

However, hormone releases also have differing impacts on the social behaviour of the two sexes. Oxytocin, which is secreted in high concentrations during positive social interactions and hugging, drives women to bond with and befriend other individuals, while in men, higher levels of the hormone may make them more competitive.

The power of the immune system

men vs women science
Cox: 'Men really are more vulnerable to getting ill from a circulating infection'

While most people are familiar with the term “man flu”, men really are more vulnerable to getting ill from a circulating infection. In general, women around the world seem to mount stronger immune responses to various pathogens, something which was made clear during the first year of the Covid-19 pandemic. Statistics across England and Wales showed that 18 per cent more men died from the virus between March 2020 and January 2021.

At the time, Prof Philip Goulder, an immunologist at the University of Oxford, said that scientists were beginning to realise that there were major differences between the male and female immune systems.

“The immune response throughout life to vaccines and infections is typically more aggressive and more effective in females,” he said. “Several factors contribute to this including the fact that females have two X chromosomes compared to one in males, and a number of critical immune genes are located on the X chromosome.”

But while this is positive for women in many ways, it also means they are at a far greater risk of autoimmune diseases, caused by the immune system responding excessively and mistakenly attacking healthy tissue.

Thicker skin

Finally, if you find yourself regularly arguing with your spouse over the temperature of the house, it’s likely to be related to the different skin thickness levels between men and women.

Men’s skin is about 25 per cent thicker than women’s, and this combined with their higher resting metabolic rate – due to their greater muscle mass – means that they feel the cold less.

So next time, your girlfriend or wife asks for a hot water bottle or the heating to be turned on, it’s because her biology means she’s sensing the cold much more acutely.


The real life situations that prove gender-based science is right

Road rage

Although research indicates that both men and women feel anger with the same frequency, women may be better at holding back their frustration. One famous study from neuroscientists at the University of Pennsylvania found that a part of the brain called the orbital frontal cortex, involved in controlling aggression, is much larger in women than men. This may be why women are better at restraining themselves from explosive outbursts – such as bellowing when another motorist overtakes you on the M25.

Resolving arguments

One of the key findings from the Stanford research was that the female participants showed greater activity in the default mode network – a system of connected brain areas that is associated with internal thought and introspection. Daydreaming or simply contemplating another person’s perspective are linked to this region – allowing women to be more reflective in conflicts, whether in office politics or the right way to stack a dishwasher.

Cleaning the fridge

Women do most of the chores around the home because men do not see mess in the same way, University of Cambridge academics suggested in December last year, in a phenomenon they described as “affordance theory”. While men will look at a pile of dishes in the sink or a messy fridge as a mess, women view it as a job in need of doing and feel an urge to do so. “Men should be encouraged to resist gendered norms by improving their sensitivity to domestic task affordances,” the researchers concluded.

Map-reading

Many romantic mini-breaks and countryside walks have been tainted by male belief in their superior powers of navigation, and – unfortunately – they may have a point. The Stanford research and other studies have hinted that men seem to display greater visual and spatial awareness on average than women, along with a better working memory – allowing them to plot a route with more confidence. Whether they can keep their female partner on the walk alongside them is another question.

Sending thank you notes

Women are better at “remembering to remember”, multiple studies have found, a useful trait when sending a birthday card to Great-Aunt Susan or planning a child’s themed outfit for World Book Day. In a 2016 study carried out by the Experimental Psychology Society, women performed better in “event-based tasks” (prompted by an external event) which would take place in the future, and when the task “required a physical response modality”.

Writing in the society’s Quarterly Journal, researcher Liana Palermo of Aston University reflected: “In daily life women might perform tasks involving prospective memory/planning skills more than men, thus enhancing their performance in remembering to remember.”

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