The
Science of Love: Cupid’s Chemicals
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
Three
Stages of Falling in 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
The Frisky
Prairie Vole
In prairie vole society, sex is the
prelude to a long-term pair bonding of a male and female. Prairie voles indulge
in far more sex than is strictly necessary for the purposes of reproduction.
It was thought that the two
hormones, vasopressin and oxytocin, released after
mating, could forge this bond. In an experiment, male prairie voles were given
a drug that suppresses the effect of vasopressin. The bond with their partner
deteriorated immediately as they lost their devotion and failed to protect
their partner from new suitors.
Looking in
their Genes
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.