I stumbled upon some interesting articles about the chemistry of ‘love’. As people have struggled for years to classify and explain what love is, there now seems a scientific explanation for it. It does take away the magic a bit. But it is rather fascinating when you read it. It may even explain why some couples remain faithfull and why others don’t. (If you want to skip the rest of my excerpt, you can go straight to the whole story by following this link to the story called “I get a kick out of you”).
So what’s the deal? Scientist have found that two particular hormones, oxytocin and vasopressin, have a lot to do with ‘love’.
The details of what is going on — the vole story, as it were — is a fascinating one. When prairie voles have sex, two hormones called oxytocin and vasopressin are released. If the release of these hormones is blocked, prairie-voles’ sex becomes a fleeting affair, like that normally enjoyed by their rakish montane cousins. Conversely, if prairie voles are given an injection of the hormones, but prevented from having sex, they will still form a preference for their chosen partner. In other words, researchers can make prairie voles fall in love — or whatever the vole equivalent of this is — with an injection.
A clue to what is happening — and how these results might bear on the human condition — was found when this magic juice was given to the montane vole: it made no difference. It turns out that the faithful prairie vole has receptors for oxytocin and vasopressin in brain regions associated with reward and reinforcement, whereas the montane vole does not. The question is, do humans (another species in the 3% of allegedly monogamous mammals) have brains similar to prairie voles?
To answer that question you need to dig a little deeper. As Larry Young, a researcher into social attachment at Emory University, in Atlanta, Georgia, explains, the brain has a reward system designed to make voles (and people and other animals) do what they ought to. Without it, they might forget to eat, drink and have sex — with disastrous results. That animals continue to do these things is because they make them feel good. And they feel good because of the release of a chemical called dopamine into the brain. Sure enough, when a female prairie vole mates, there is a 50% increase in the level of dopamine in the reward centre of her brain.
Similarly, when a male rat has sex it feels good to him because of the dopamine. He learns that sex is enjoyable, and seeks out more of it based on how it happened the first time. But, in contrast to the prairie vole, at no time do rats learn to associate sex with a particular female. Rats are not monogamous.
This is where the vasopressin and oxytocin come in. They are involved in parts of the brain that help to pick out the salient features used to identify individuals. If the gene for oxytocin is knocked out of a mouse before birth, that mouse will become a social amnesiac and have no memory of the other mice it meets. The same is true if the vasopressin gene is knocked out.
The salient feature in this case is odour. Rats, mice and voles recognise each other by smell. Christie Fowler and her colleagues at Florida State University have found that exposure to the opposite sex generates new nerve cells in the brains of prairie voles — in particular in areas important to olfactory memory. Could it be that prairie voles form an olfactory “image” of their partners — the rodent equivalent of remembering a personality — and this becomes linked with pleasure?
Dr Young and his colleagues suggest this idea in an article published last month in the Journal of Comparative Neurology. They argue that prairie voles become addicted to each other through a process of sexual imprinting mediated by odour. Furthermore, they suggest that the reward mechanism involved in this addiction has probably evolved in a similar way in other monogamous animals, humans included, to regulate pair-bonding in them as well.
Wow, I find that fascinating! And there is even more interesting to discover:
In 2000, Andreas Bartels and Semir Zeki of University College, London, located the areas of the brain activated by romantic love. They took students who said they were madly in love, put them into a brain scanner, and looked at their patterns of brain activity.
The results were surprising. For a start, a relatively small area of the human brain is active in love, compared with that involved in, say, ordinary friendship. “It is fascinating to reflect”, the pair conclude, “that the face that launched a thousand ships should have done so through such a limited expanse of cortex.” The second surprise was that the brain areas active in love are different from the areas activated in other emotional states, such as fear and anger. Parts of the brain that are love-bitten include the one responsible for gut feelings, and the ones which generate the euphoria induced by drugs such as cocaine. So the brains of people deeply in love do not look like those of people experiencing strong emotions, but instead like those of people snorting coke. Love, in other words, uses the neural mechanisms that are activated during the process of addiction. “We are literally addicted to love,” Dr Young observes. Like the prairie voles.
And:
(…)Then there is attraction, or the state of being in love (what is sometimes known as romantic or obsessive love). This is a refinement of mere lust that allows people to home in on a particular mate. This state is characterised by feelings of exhilaration, and intrusive, obsessive thoughts about the object of one’s affection. Some researchers suggest this mental state might share neurochemical characteristics with the manic phase of manic depression. Dr Fisher’s work, however, suggests that the actual behavioural patterns of those in love — such as attempting to evoke reciprocal responses in one’s loved one — resemble obsessive compulsive disorder (OCD).
That raises the question of whether it is possible to “treat” this romantic state clinically, as can be done with OCD. The parents of any love-besotted teenager might want to know the answer to that. Dr Fisher suggests it might, indeed, be possible to inhibit feelings of romantic love, but only at its early stages. OCD is characterised by low levels of a chemical called serotonin. Drugs such as Prozac work by keeping serotonin hanging around in the brain for longer than normal, so they might stave off romantic feelings. (This also means that people taking anti-depressants may be jeopardising their ability to fall in love.)
Hmm, that is just so fascinating!
So love, in all its glory, is just, it seems, a chemical state with genetic roots and environmental influences. But all this work leads to other questions. If scientists can make a more sociable mouse, might it be possible to create a more sociable human? And what about a more loving one? A few people even think that “paradise-engineering”, dedicated to abolishing the “biological substrates of human suffering”, is rather a good idea.
And then the part about “treatment” is also interesting:
Progress in predicting the outcome of relationships, and information about the genetic roots of fidelity, might also make proposing marriage more like a job application — with associated medical, genetic and psychological checks. If it were reliable enough, would insurers cover you for divorce? And as brain scanners become cheaper and more widely available, they might go from being research tools to something that anyone could use to find out how well they were loved. Will the future bring answers to questions such as: Does your partner really love you? Is your husband lusting after the au pair?
And then there are drugs. Despite Dr Fisher’s reservations, might they also help people to fall in love, or perhaps fix broken relationships? Probably not. Dr Pfaus says that drugs may enhance portions of the “love experience” but fall short of doing the whole job because of their specificity. And if a couple fall out of love, drugs are unlikely to help either. Dr Fisher does not believe that the brain could overlook distaste for someone — even if a couple in trouble could inject themselves with huge amounts of dopamine.
However, she does think that administering serotonin can help someone get over a bad love affair faster. She also suggests it is possible to trick the brain into feeling romantic love in a long-term relationship by doing novel things with your partner. Any arousing activity drives up the level of dopamine and can therefore trigger feelings of romance as a side effect. This is why holidays can rekindle passion. Romantics, of course, have always known that love is a special sort of chemistry. Scientists are now beginning to show how true this is.
So there it is: love as a chemical proccess. The only thing I do not like about it, is that is kind of throws out the whole concept of free will (if there is such a thing).
Still: life is a mystery too me….