The scientific briefing with Luke Boulter
With Valentines Day just passed, the sickening cards and small tokens of affection are neatly propped at the back of your bookshelves, ready to be dusted off and admired whenever you feel the need. Okay, so I am a bitter and lonely scientist, but what is it that causes us to lust and even fall in love with someone? Is love a cognitive human trait or is it a cry back to our ancestral selves and the result of our anatomy?
The body is under massive chemical control; it is stimulated and repressed by myriad different molecules, known as hormones. Hormones are responsible for stimulating hunger, for causing you to develop properly in the womb and for that little nervous jitter you feel when the person you fancy stumbles past you. Helen Fisher of Rutgers University in New Jersey has proposed a three step program in attraction, each having its own array of chemical involvement: Her first stage is ‘Lust’; this phase is driven purely by sex hormones, oestrogen and testosterone. Testosterone is not confined to men; it has been shown that there is an active level in women too.
During lust, female testosterone levels increase, making them more aggressive and forward; in men testosterone levels temporarily decrease, allowing them to become more accepting towards a partner. These hormones are associated with the release of corticosteroids, such as adrenaline, the flight or fight hormone which prepares the body to flee or stand brave and face a foe (or in this case, a love).
Fisher’s second phase is ‘Attraction’. It is in this stage that the major hormone players kick in; dopamine and adrenaline are released, causing the body to go a little off balance, and sleep and hunger are affected. Strangely enough, studies in Italy have shown that when in love, serotonin levels drop by as much as 40% and is comparable with levels found in sufferers of the mental illness Obsessive Compulsive Disorder (OCD). Serotonin levels have also been shown to affect happiness, and are directly linked to depression in young adults. After about a year or so the serotonin levels return to normal, and it is suggested that this fall in serotonin is a mechanism to allows us to get over the initial fear of being with a new person.
The third and final stage of Fisher’s idea is that of ‘Attachment’, and at this point two key hormones, oxytocin and vasopressin, are present. Upon reaching orgasm, the levels of oxytocin rocket, causing the body to form an emotional attachment to the other person. It is also released during child-birth and breast-feeding and helps to stabilise the bond between mother and child. Vasopressin is another attachment hormone which plays a crucial role in monogamous pairing; it is the hormone which allows for a protective attachment, meaning you will challenge competition for your partner. If vasopressin is removed then protective attachment subsides almost immediately.
The idea that being in love is like being on a drug-induced high may not be too far from the truth. Amphetamines stimulate the same areas of the brain normally activated by the neurotransmitter phenylethylamine, which is highly present in large amounts during courtship.
I’m not suggesting that you are just a slave to your hormones, as there is plenty of evidence that attraction is based not only on hormones but also on body language and external signals. It takes between ninety seconds and four minutes to decide if you fancy someone, 55% of your attraction to someone is conveyed in body language and 38% through the tones of your voice. Chat-up lines, it seems, are a turn off, but fortunately only 7% of flirtation relies on the actual words, so don’t worry about the nervous mumblings; as long as you stand right, all ought to be be fine.
So what makes someone attractive? To be honest, we are no better here than peacocks or any other animal; we have behavioural patterns and signals we use to convey our sexual urges, and also use physical features to determine the ‘genetic fitness’ of our potential mates.
Scientists say a symmetrical face is an indicator of genetic fitness, as is an hour-glass figure. The ideal hip ratio for a woman is 0.7 (ratio being calculated by waist measurement/hip measurement) and is probably indicative of a woman’s reproductive health. During aging, women’s waists become less pronounced as she becomes less fertile. Interestingly enough though, the most overwhelming factor in physical attraction is our own narcissism.
David Perrett, a cognitive psychologist from the University of St. Andrews takes photos of peoples faces and morphs them into the opposite sex. He then randomises the picture with many others, and the participant has to pick out the most attractive photo. More often than not they pick their own morphed picture, they don’t recognise it, they just know they like the ‘person’.
Smell also plays a crucial role in detecting a potential mate, as pheromones are sensed by a small organ in the nose. Pheromones vary from person to person, and change according to variations in immune systems. Rats smell pheromones in urine to find a compatible mate and it has also been shown that adult humans may use pheromones to detect a compatible partner whose immune system is strong and will be passed on to any offspring. Fortunately we secrete pheromones from our skin, so you won’t have to take a urine sample to find out.