Its impulses can cause us all to feel the butterflies in our stomachs or the pain that comes with its withdrawal. We all know its unique power to shape the parent-child relationship and, if we’re lucky, we’ve felt its gentle warmth as we’ve looked at the face of a friend. Even a fluffy one.
What do we know about love? While poets were always able to share their thoughts with us, scientists are now joining the conversation. Thanks to ever-improving technology, modern scientists are able to look inside the human — and non-human — brain to find answers to some of our oldest questions on all things amorous. Scientists can identify the neurochemicals which form love’s foundations, determine the formulas for sexual attraction and provide a scientific explanation as to why your husband forgot your anniversary.
Anna Machin, an Oxford University Anthropologist has searched the literature and spoken with the top experts to create Why We Love.
Continue reading to learn all about the strongest and sweetest human emotion. . .
Anna Machin shares the results of her research on love, after speaking with leading experts and scouring literature for Why We Love (file picture).
DRESS SIZE DOESN’T MATTER BUT THE HIPS DO
The human mating game is a competitive market akin to the stock market, but rather than our worth being expressed in pounds, it’s expressed in mate value.
Evolution desires that women are able to become pregnant and live long enough to have a child. For men, it’s all about their ability to protect, provide and commit to their family — remember when this system evolved, women were either pregnant or breastfeeding constantly, so were very vulnerable.
Your brain relies on your senses for key information to calculate this figure. A woman’s waist-to-hip ratio, for example, is one of the most robust indicators of health and fertility, and cross-cultural studies of female body shape have repeatedly shown that the most attractive waist-to-hip ratio is 0.7 — the classic hourglass. You might be surprised by this because we tend to focus so much on being thin in Western culture.
But remember it is the ratio of waist to hips that’s key, so you can be a size 8 or 18 and the 0.7 is still what’s important.
Indeed, we’ve observed its importance not just in the lab, but in real life. In a 2015 eye-tracking experiment, scientists in Texas showed that men, and interestingly women, focused first and spent the longest time looking at an unknown woman’s midriff before moving on to her face, suggesting that when deciding who to approach as a potential mate — or checking out the competition — the waist-to-hip ratio is one of the first pieces of information processed by our brain.
Men are meanwhile assessed on their shoulder-to-waist ratio — a 1.4 is the goal, although that’s rarely displayed nowadays by anyone other than an Olympic athlete or gym junkie.
A symmetrical appearance is more appealing to women in a short-term relationship or a committed one. For both sexes, symmetry is a sign of good genes, and if he’s not in it for the long haul, his genes are the only thing she’ll be getting from him.
The brain is, in general, the most beautiful organ of the body. The use of creative language, artistic expression and humour are indicators of our cognitive flexibility, which we’d all like our offspring to inherit because it’s linked to intelligence. It’s for this reason, in part, that famous rock stars or even politicians — think Mick Jagger with eight children or, ahem, Boris Johnson with seven — seem to have above-average reproductive success. Women seem to find them irresistible despite the fact they don’t stick with one mate.
Cross-cultural studies of female body shape have repeatedly shown that the most attractive waist-to-hip ratio is 0.7 — the classic hourglass (file image)
Are WOMEN more sexy than MEN?
You will need to take 32 romantically involved people, 16 male and 16 female, and put them in an individual fMRI scanner. It maps brain activity. You can show them pictures showing different instances of love. These could range from an intimate couple standing in the sunset, to a family completing the grocery shop. How would you like to see it?
One psychologist and her team did this to try to understand whether differences we think we know about men’s and women’s approaches to love had any biological truth.
Overall, what they found was that, regardless of sex, the more romantic the scenario — sunsets rather than supermarkets — the more the emotional centres of the brain lit up, in both men and women.
However, if you look beyond the similarities, there are many differences.
Some studies have shown that by the time children are eight, boys and girls are beginning to conceptualise romantic love in different ways (file image)
Men have more brain areas that are involved in thinking than in feeling. This suggests that it takes more effort to evaluate and consider romantic situations than for women who do it instinctively.
Is this his excuse for not remembering your wedding anniversary? My husband finds the conclusion to this study ‘profoundly patronising’, because it implies that men are less emotionally literate, or evolved, than women.
But perhaps it’s nothing to do with evolution. The human brain is extremely plastic, as we know. We know that it can be changed, especially in the earliest years of life, and that our environment plays a crucial role in shaping it.
So it may be that our culture — which tells boys that they are the rational sex while women are at the mercy of their emotions — has caused our brains to appear the way they do on the scanner screen. Another study has shown that boys and girls begin to think about romantic love differently at eight years old.
And we also know the pink aisle in the toy shop is full of hearts and flowers while the boys’ aisle, well, isn’t.
MAKE HIM FALL FOR YOU — GO TO THE GYM!
You might be able to increase your odds by leveraging the love-chemistry power in different ways.
Oxytocin is one of the ingredients of the romance cocktail, but it’s also joined by dopamine, serotonin and beta-endorphin — all happy chemicals which influence the fine detail of brain activity. The most essential of them all is beta-endorphin. This is the body’s natural opiate, like heroin or morphine, so once someone has experienced an interaction that causes a release of it, they will keep coming back for more.
Anna Machin explained that a day filled with endorphin-inducing activities like dancing, exercise or comedy can result in success (file image).
The wonderful emotions of closeness, happiness, comfort, and warmth that it brings us are addictive. If we have a good relationship with someone we care about, it is like a high-dose opiate. But if the person we are interacting with goes away, the cravings start and our motivations to get back to the source increase. This means that we will always be drawn to our loved ones.
However, if we’re dumped, we experience a huge opiate withdrawal. This is why it is so painful to lose love.
This is how to be successful in dating. Organise a date that is full of fun, endorphin-inducing activities. You will find the right person for you through exercise and laughter. A work out session, dance class, or comedy club can help increase your chances of finding the one.
You can replenish your supply by going on a run or getting a massage to stimulate the release of beta-endorphin and oxytocin. Dopamine can be restored by a good session of chocolate eating.
DON’T MUM and DAD LOVE US DIFFERENTLY
Thanks to an evolutionary flaw, homo sapiens father was able to be enlisted in childcare later than mom.
The quirk relates to the massive size of the human brain – it’s six times bigger than it should be for a mammal of our size, which means that if a baby went full term, her head would not fit through the birth canal, mum and baby would die and the species line would come to an abrupt end. We’ve evolved therefore to birth our babies very early, resulting in a baby whose brain is not yet fully developed – and hence is incapable of doing anything alone for a significant period of time post-birth.
Anna claimed that mothering was as ancient as time. This is evident in reptiles as well as humans. (file image).
When human evolution started, mothers turned to their female relatives to care for their babies. Human fathers weren’t around. However, around 500,000 years ago evolution brought men along and dads started to fill the gap.
This evolutionary time-lag can be seen today. Israeli scientists in 2012 placed fifteen pairs of fathers and daughters of 6-month-old infants under an fMRI scanner. This allowed them to assess their brain activity while watching videos of their kids playing. Both mums and dads showed activity in the areas of the brain linked to empathy and understanding others’ feelings, equally demonstrating the strong attachment they felt to their child.
There was however a marked difference in brain activity. In mothers, the evolutionarily-ancient limbic system, which reflects the key characteristics of mothering — giving affection and nurturing — was the most active part of the brain.
By contrast, in fathers the relatively young neocortex, which is associated with ‘social cognition’, was set alight, seeming to reflect dad’s role in teaching and encouraging his child to strive towards independence.
While mothering has existed since the beginning of time in reptiles and humans, human fatherhood is now hardwired into our brains.
Adapted by ALISON ROBERTS from Why We Love by Anna Machin (£18.99, Weidenfeld & Nicolson) out January 6. © Anna Machin 2022. To order a copy for £17.09 go to mailshop.co.uk/books or call 020 3176 2937. Free UK delivery on orders over £20. The offer price is valid up to 10/01/22.