If you have ever wondered what is happening to you when you fall in love, you should ask a vole.
It has been brought to my attention that Sunday is Valentine’s day, not by my husband naturally, but by my calendar app, the font of all knowledge in our household. February 14th, the day of unrequited passions, infatuations and enduring love. The day of red roses, balloons, chocolate and squirmingly sentimental, overpriced cards.
But how exactly would you define love?
The Oxford English dictionary defines love as an intense feeling of deep affection, a great interest and pleasure in a person or a thing, which seems kind of wish-washy to me, so I turned to the Urban Dictionary, a source of such wisdom and hilarity. Of the many definitions offered up, the one I particularly like defines love as ‘a widespread incurable disease which is known to affect mind and sometimes body. Symptoms may include affected judgement, lightheadedness, eye-watering, chest pains and increased need to be with the person who infected you. Highly contagious and can be deadly.’
I think that if you have ever been in love, much of that rings true!
In 2005, Helen Fisher, a celebrate biological anthropologist, published a groundbreaking study that analysed the functional MRI brain scans of 2500 college students in love. They were shown photos of the person they were in love with and casual acquaintances and on seeing photos of the person they were romantically involved with, the scans showed that their brains were particularly active in areas rich in dopamine, the feel-good neurotransmitter; these are the regions of the brain associated with reward detection and expectation, with pleasure and focused attention and in integrating sensory experience with social behaviour.
But is it not just dopamine that is responsible for the symptoms of being in love — the racing heart, sweaty palms, flushed cheeks, passion and crippling anxiety. When we fall in love, stress hormones such as cortisol spike to prepare our bodies for the crisis in hand. This leads to a fall in serotonin levels which causes intrusive, pre-occupying thoughts — in fact all the obsessive-compulsive behaviours associated with infatuation.
Oxytocin, the love hormone, is released during sex and heightened by skin to skin contact. It deepens feelings of attachment and makes couples feel closer to each other engendering a sense of contentment, calm and security.
Vasopressin is another love hormone linked to behaviour that produces long term relationships. It would seem that men are more sensitive to vasopressin and women to oxytocin, although men who inhale oxytocin become temporarily more empathetic, sensitive and cuddly apparently.
Both of these hormones have been extensively studied in voles — prairie and montane voles are 99% genetically identical but whereas prairie voles form monogamous life-long relationships, their cousins, the montane voles are known for their promiscuity. Prairie voles have much higher densities of oxytocin and vasopressin receptors in the dopamine reward centres of their brains than the montane voles. And if you block these receptors, the prairie voles ditch their monogamous relationships for a life of sex, drugs and rock and roll.
The accumulated effect of all these surging hormones and neurotransmitters works to deactivate the neural pathways responsible for negative emotions such as fear and social judgement. We are no longer capable of making critical assessments of other people — the adage love is blind rings true. We are also more likely to engage in reckless behaviour when we are in love.
The good new is though that after a year or two, our stress hormones levels return to normal and the compassionate, routine sort of love that develops from longterm relationships serves to act as a buffer against stress with brain areas rich in oxytocin and vasopressin receptors remaining active. This would explain the health benefits to being in a long-term, loving relationship; fewer visits to the doctor, less alcohol and substance abuse, lower blood pressure, less anxiety, better stress management, better pain control, fewer colds, faster healing, and a longer and happier life.
As Albert Einstein allegedly once said, ‘You can’t blame gravity for falling in love’, but you can blame neurochemistry.
*strangely I couldn’t seem to find any images of voles in love - plenty of flowers and chocolate, but no voles.
