The Science of Love

Key Points:
- There are three phases to falling in love and different hormones are involved at each stage
- Events occurring in the brain when we are in love have similarities with mental illness
- When we are attracted to somebody, it could be because subconsciously we like their genes
- Smell could be as important as looks when it comes to the fanciability factor. We like the look and smell of people who are most like our parents

Cupid's chemicals
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Flushed cheeks, a racing heart beat and clammy hands are some of the outward signs of being in love. But inside the body there are definite chemical signs that cupid has fired his arrow.

When it comes to love it seems we are at the mercy of our biochemistry. One of the best known researchers in this area is Helen Fisher of Rutgers University in New Jersey. She has proposed that we fall in love in three stages. Each involving a different set of chemicals.

The Three Stages of Love:
Stage 1: LUST
Lust is driven by the sex hormones testosterone and oestrogen. Testosterone is not confined only to men. It has also been shown to play a major role in the sex drive of women. These hormones as Helen Fisher says "get you out looking for anything".

Stage 2: ATTRACTION
This is the truly love-struck phase. When people fall in love they can think of nothing else. They might even lose their appetite and need less sleep, preferring to spend hours at a time daydreaming about their new lover.
In the attraction stage, a group of neuro-transmitters called 'monoamines' play an important role:
- Dopamine - Also activated by cocaine and nicotine
- Norepinephrine - Otherwise known as adrenalin. Starts us sweating and gets the heart racing
- Serotonin - One of love's most important chemicals and one that may actually send us temporarily insane

Stage 3: ATTACHMENT
This is what takes over after the attraction stage, if a relationship is going to last. People couldn't possibly stay in the attraction stage forever, otherwise they'd never get any work done! Attachment is a longer lasting commitment and is the bond that keeps couples together when they go on to have children. Important in this stage are two hormones released by the nervous system, which are thought to play a role in social attachments:
- Oxytocin - This is released by the hypothalamus gland during child birth and also helps the breast express milk. It helps cement the strong bond between mother and child. It is also released by both sexes during orgasm and it is thought that it promotes bonding when adults are intimate. The theory goes that the more sex a couple has, the deeper their bond becomes
- Vasopressin - Another important chemical in the long-term commitment stage. It is an important controller of the kidney and its role in long-term relationships was discovered when scientists looked at the prairie vole

Looking in their genes
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When it comes to choosing a partner, are we at the mercy of our subconscious? Researchers studying the science of attraction draw on evolutionary theory to explain the way humans pick partners.
It is to our advantage to mate with somebody with the best possible genes. These will then be passed on to our children, ensuring that we have healthy kids, who will pass our own genes on for generations to come.
When we look at a potential mate, we are assessing whether we would like our children to have their genes. There are two ways of doing this that are currently being studied: pheromones and appearance.

The Science of Flirting
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There are certain things you can do that might help your date go with a bang - and turn into something more serious.

Ditch the chat up lines
It can take between 90 seconds and 4 minutes to decide if we fancy someone. But this has little to do with your smooth-talking. As far as attraction goes, here's how we get the message:
- 55% is through body language
- 38% is the tone and speed of our voice
- Only 7% is through what we say

Stare into each others' eyes
New York psychologist, Professor Arthur Arun, has been studying the dynamics of what happens when people fall in love. He has shown that the simple act of staring into each other's eyes has a powerful impact. He asked two complete strangers to reveal to each other intimate details about their lives. This carried on for an hour and a half. The two strangers were then made to stare into each others eyes without talking for four minutes. Afterwards many of his couples confessed to feeling deeply attracted to their opposite number and two of his subjects even married afterwards. When we are aroused and interested in what we are looking at our pupils dilate. In medieval Italy, women put belladonna into their eyes to make them look bigger. In fact, bella donna means 'beautiful lady'. However, this is not recommended, as belladonna is a kind of poison!

Match their moves
When people are attracted to each other, they tend to sit or stand in the same way and copy each other's physical gestures. This is known as 'mirroring'. When someone does this, it marks good communication and shows us that our interest is reciprocated. Mirroring also happens when talking to close friends as well as potential lovers, so be careful as you may misread signs of friendship as signs of love.

Don't play hard to get
Research suggest that playing hard to get doesn't usually work. However, there is a theory that we tend to fancy people who are hard to get for everyone else, but easy for us to get. Scientists tested this 'selective difficulty' theory by using a computer dating experiment. One woman was keen to meet any of the dates that the computer selected for her. Another played hard to get and wasn't enthusiastic towards any of her computer matches. A third was selective and only showed interest in one of the candidates. Out of all three women, the choosy woman was the most preferred by all the male participants.

Be dangerous
Another experiment showed that if people experience fear on a date they often misinterpret that feeling as love. So dates at a theme park are likely to be successful. A bungee jump might seal your relationship for life! In fact, people who both like the same level of thrills and excitement are more likely to be compatible.


What Makes You Fancy Someone?
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Appearance could be another indicator of the quality of a person's genes. Research suggests that there are certain things we all look for - even if we don't know it.

Perfect symmetry
It is thought that asymmetrical features are a sign of underlying genetic problems. Numerous studies in humans have shown that men in particular go for women with symmetrical faces. The preference in women for symmetry is not quite so pronounced. Women are also looking for a man's ability to offer food and protection. This might not be indicated in their genes, but in their rank and status, for example.

The hour-glass figure
Studies have shown that men prefer women with a waist to hip ratio of 0.7. You can calculate your own using this formula: waist measurement ÷ hip measurement = ratio. This seems to apply whatever the woman's overall weight. A group of researchers even compared this ratio with the average ratio of Miss America winners over the years. It was exactly the same. This ratio would seem to make sense as an indicator of a woman's reproductive health. When women age their waist tends to become less pronounced as they put on fat around the stomach. This coincides with them becoming less fertile.

Learn to love yourself
Have you noticed how many married couples look quite similar? Studies have shown that more than anything we prefer somebody who looks just like we do. From a batch of individual photographs people can spot who are the couples with unnerving reliability. Research has uncovered that there is a correlation in couples between their:
- Lung volumes
- Middle finger lengths
- Ear lobe lengths
- Overall ear size
- Neck and wrist circumferences
- Metabolic rates

Mummy's boys and Daddy's girls?
The latest studies indicate that what people really, really want is a mate that looks like their parents. Women are after a man who is like their father and men want to be able to see their own mother in the woman of their dreams. At the University of St Andrews in Scotland, cognitive psychologist David Perrett studies what makes faces attractive. He has developed a computerised morphing system that can endlessly adjust faces to suit his needs. Students in his experiments are left to decide which face they fancy the most. Perrett has taken images of students' own faces and morphed them into the opposite sex. Of all the faces on offer, this seems to be the face that subject will always prefer. They can't recognize it as their own, they just know they like it. Perrett suggests that we find our own faces attractive because they remind us of the faces we looked at constantly in our early childhood years - Mum and Dad. Even the pheromone studies are now showing a preference for our parents' characteristics.

Will it last?
Unfortunately there's no way of telling for certain if a relationship will last. But there might be some clues in your partner's family! In studies of behavioral genetics it has been shown that a person's tendency to divorce is written in their genes. When scientists studied identical twins, they found that whatever their degree of marriage success was, they shared it with their sibling. Men who went through multiple marriages were highly likely to have a twin brother who did the same.

The numbers game
Perhaps the best indication as to whether your love will last come from statistical studies. Researchers have come up with several predictors for success. This is based on how you met and when, how you resolve conflict and how similar you and your expectations are.


Does Love Drive You Mad?
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In 1990, a study in Italy indicated that people who have recently fallen in love have some of the symptoms of 'Obsessive Compulsive Disorder' or OCD. People with OCD behave obsessively about certain things. They might be constantly washing their hands, or need to continually check to see if the door is closed.

Does love make you sad?
Rather than making you happy, love could actually make you depressed. One symptom of OCD appears to be unusually low levels of the neuro-transmitter 'serotonin'. Low levels of serotonin have been associated with anxiety and depression. Italian students who claimed they had recently fallen in love were found to have serotonin levels 40% lower than their peers. However, the biochemical effect of falling in love didn't last forever. When the same students were tested after their relationship was a year old, their levels had returned to normal. One author of the study has suggested that we require this chemical response for relationships to survive. After all, we'd have to be mad to fall in love wouldn't we?

Virility
Another interesting finding is that people with low serotonin levels tend to have a lot of sex. If men have a particular version of a gene known as the 'serotonin transporter', they will have lower levels of serotonin in their brains. They tend to be more anxious than other men and also more sexually active.

Love on the brain
Brain imaging techniques have been put to use in the name of love. Andreas Bartels and Semir Zeki at University College London used functional Magnetic Resonance Imaging (fMRI) to take pictures of the lover's brain. Whilst inside the scanner, loved-up students were shown pictures of their new flame. They were also shown images of platonic friends of the opposite sex. Zeki and Bartels were struck by how clear cut the pattern of brain activity was when students were looking at their new love. Four areas of the brain became active, and one area noticeably inactive, when the students had love on their mind. The active areas include one responsible for 'gut' feelings and one that is known to respond to euphoria-inducing drugs. The lights go off however, in the prefrontal cortex, an area that is overactive in depressed patients.


Sensual Signals
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Sniffing out Mr or Mrs Right
Human pheromones are a hot topic in research. They are odourless chemicals detected by an organ in the nose. Some scientists believe they could be the key to choosing a suitable lover.

Love rats
Pheromones are already well understood in other mammals, especially rodents. These animals possess something called a 'vomeronasal organ' (or VNO) inside their noses. They use it to detect pheromones in the urine of other rats and use this extra sense to understand social relationships, identify the sex of fellow rats and find a mate. In 1985, researchers at the University of Colorado found evidence that this organ also exists in most adult humans. So humans could also respond to pheromones. Rats have different pheromones in their urine, depending on the make-up of their immune system. When rats choose a mate, they must avoid partners with an immune system too similar to their own, so that their babies can fight off a wider range of infections. As well as lurking in urine, pheromones are also found in sweat.

Love is...a sweaty T-shirt competition
In 1995, Claus Wedekind of the University of Bern in Switzerland, asked a group of women to smell some unwashed T-shirts worn by different men. What he discovered was that women consistently preferred the smell of men whose immune systems were different from their own. This parallels what happens with rodents, who check-out how resistant their partners are to disease by sniffing their pheromones. So it seems we are also at the mercy of our lover's pheromones, just like rats.

Fatherly fragrances
At the University of Chicago, Dr Martha McClintock has shown in her own sweaty T-shirt study that what women want most is a man who smells similar to her father. Scientists suggest that a woman being attracted to her father's genes makes sense. A man with these genes would be similar enough that her offspring would get a tried and tested immune system. On the other hand, he would be different enough to ensure a wide range of genes for immunity. There seems to be a drive to reach a balance between reckless out-breeding and dangerous inbreeding.


Source:
- http://www.bbc.co.uk/science/hottopics/love/