Please..do explain love at your peril! ga peduli how hard you try, love ain’t that simple, it has never been and it won’t ever be. This paper however, very interesting as it is unussually try to explain love from the perspective of science, a truly educating read. baca..en dijamin kalian akan manggut manggut sambil garuk garuk kepala, and mungkin angkat topi buat penulisnya. anyone suka kimia?

The science of love

I get a kick out of you

Scientists are finding that, after all, love really is down to a chemical addiction between people

OVER the course of history it has been artists, poets and
playwrights who have made the greatest progress in humanity’s
understanding of love. Romance has seemed as inexplicable as the beauty
of a rainbow. But these days scientists are challenging that notion,
and they have rather a lot to say about how and why people love each
other.

Is this useful? The scientists think so. For a start, understanding
the neurochemical pathways that regulate social attachments may help to
deal with defects in people’s ability to form relationships. All
relationships, whether they are those of parents with their children,
spouses with their partners, or workers with their colleagues, rely on
an ability to create and maintain social ties. Defects can be
disabling, and become apparent as disorders such as autism and
schizophrenia—and, indeed, as the serious depression that can result
from rejection in love. Research is also shedding light on some of the
more extreme forms of sexual behaviour. And, controversially, some
utopian fringe groups see such work as the doorway to a future where
love is guaranteed because it will be provided chemically, or even
genetically engineered from conception.

ocument.write(’\'The scientific tale of love begins innocently enough, with voles.
The prairie vole is a sociable creature, one of the only 3% of mammal
species that appear to form monogamous relationships. Mating between
prairie voles is a tremendous 24-hour effort. After this, they bond for
life. They prefer to spend time with each other, groom each other for
hours on end and nest together. They avoid meeting other potential
mates. The male becomes an aggressive guard of the female. And when
their pups are born, they become affectionate and attentive parents.
However, another vole, a close relative called the montane vole, has no
interest in partnership beyond one-night-stand sex. What is intriguing
is that these vast differences in behaviour are the result of a mere
handful of genes. The two vole species are more than 99% alike,
genetically.

Why do voles fall in 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.

You might as well face it…

Sex stimulates the release of vasopressin and oxytocin in people, as
well as voles, though the role of these hormones in the human brain is
not yet well understood. But while it is unlikely that people have a
mental, smell-based map of their partners in the way that voles do,
there are strong hints that the hormone pair have something to reveal
about the nature of human love: among those of Man’s fellow primates
that have been studied, monogamous marmosets have higher levels of
vasopressin bound in the reward centres of their brains than do
non-monogamous rhesus macaques.

Other approaches are also shedding light on the question. 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.

It seems possible, then, that animals which form strong social bonds
do so because of the location of their receptors for vasopressin and
oxytocin. Evolution acts on the distribution of these receptors to
generate social or non-social versions of a vole. The more receptors
located in regions associated with reward, the more rewarding social
interactions become. Social groups, and society itself, rely ultimately
on these receptors. But for evolution to be able to act, there must be
individual variation between mice, and between men. And this has
interesting implications.

Last year, Steven Phelps, who works at Emory with Dr Young, found
great diversity in the distribution of vasopressin receptors between
individual prairie voles. He suggests that this variation contributes
to individual differences in social behaviour—in other words, some
voles will be more faithful than others. Meanwhile, Dr Young says that
he and his colleagues have found a lot of variation in the
vasopressin-receptor gene in humans. “We may be able to do things like
look at their gene sequence, look at their promoter sequence, to
genotype people and correlate that with their fidelity,” he muses.

It has already proved possible to tinker with this genetic
inheritance, with startling results. Scientists can increase the
expression of the relevant receptors in prairie voles, and thus
strengthen the animals’ ability to attach to partners. And in 1999, Dr
Young led a team that took the prairie-vole receptor gene and inserted
it into an ordinary (and therefore promiscuous) mouse. The transgenic
mouse thus created was much more sociable to its mate.

Love, love me do

Scanning the brains of people in love is also helping to refine
science’s grasp of love’s various forms. Helen Fisher, a researcher at
Rutgers University, and the author of a new book on love*,
suggests it comes in three flavours: lust, romantic love and long-term
attachment. There is some overlap but, in essence, these are separate
phenomena, with their own emotional and motivational systems, and
accompanying chemicals. These systems have evolved to enable,
respectively, mating, pair-bonding and parenting.

Lust, of course, involves a craving for sex. Jim Pfaus, a
psychologist at Concordia University, in Montreal, says the aftermath
of lustful sex is similar to the state induced by taking opiates. A
heady mix of chemical changes occurs, including increases in the levels
of serotonin, oxytocin, vasopressin and endogenous opioids (the body’s
natural equivalent of heroin). “This may serve many functions, to relax
the body, induce pleasure and satiety, and perhaps induce bonding to
the very features that one has just experienced all this with”, says Dr
Pfaus.

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.) But once romantic love begins in
earnest, it is one of the strongest drives on Earth. Dr Fisher says it
seems to be more powerful than hunger. A little serotonin would be
unlikely to stifle it.

Wonderful though it is, romantic love is unstable—not a good basis
for child-rearing. But the final stage of love, long-term attachment,
allows parents to co-operate in raising children. This state, says Dr
Fisher, is characterised by feelings of calm, security, social comfort
and emotional union.

Because they are independent, these three systems can work
simultaneously—with dangerous results. As Dr Fisher explains, “you can
feel deep attachment for a long-term spouse, while you feel romantic
love for someone else, while you feel the sex drive in situations
unrelated to either partner.” This independence means it is possible to
love more than one person at a time, a situation that leads to
jealousy, adultery and divorce—though also to the possibilities of
promiscuity and polygamy, with the likelihood of extra children, and
thus a bigger stake in the genetic future, that those behaviours bring.
As Dr Fisher observes, “We were not built to be happy but to reproduce.”

The stages of love vary somewhat between the sexes. Lust, for
example, is aroused more easily in men by visual stimuli than is the
case for women. This is probably why visual pornography is more popular
with men. And although both men and women express romantic love with
the same intensity, and are attracted to partners who are dependable,
kind, healthy, smart and educated, there are some notable differences
in their choices. Men are more attracted to youth and beauty, while
women are more attracted to money, education and position. When an
older, ugly man is seen walking down the road arm-in-arm with a young
and beautiful woman, most people assume the man is rich or powerful.

These foolish things

Of course, love is about more than just genes. Cultural and social
factors, and learning, play big roles. Who and how a person has loved
in the past are important determinants of his (or her) capacity to fall
in love at any given moment in the future. This is because
animals—people included—learn from their sexual and social experiences.
Arousal comes naturally. But long-term success in mating requires a
change from being naive about this state to knowing the precise factors
that lead from arousal to the rewards of sex, love and attachment. For
some humans, this may involve flowers, chocolate and sweet words. But
these things are learnt.

If humans become conditioned by their experiences, this may be the
reason why some people tend to date the same “type” of partner over and
over again. Researchers think humans develop a “love map” as they grow
up—a blueprint that contains the many things that they have learnt are
attractive. This inner scorecard is something that people use to rate
the suitability of mates. Yet the idea that humans are actually born
with a particular type of “soul mate” wired into their desires is
wrong. Research on the choices of partner made by identical twins
suggests that the development of love maps takes time, and has a strong
random component.

Work on rats is leading researchers such as Dr Pfaus to wonder
whether the template of features found attractive by an individual is
formed during a critical period of sexual-behaviour development. He
says that even in animals that are not supposed to pair-bond, such as
rats, these features may get fixed with the experience of sexual
reward. Rats can be conditioned to prefer particular types of
partner—for example by pairing sexual reward with some kind of cue,
such as lemon-scented members of the opposite sex. This work may help
the understanding of unusual sexual preferences. Human fetishes, for
example, develop early, and are almost impossible to change. The
fetishist connects objects such as feet, shoes, stuffed toys and even
balloons, that have a visual association with childhood sexual
experiences, to sexual gratification.

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.

As time goes by

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.

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