Love really is blind
July 5, 2004
Neuroscience can at last explain why
we can't see faults in our lovers or children. Raj
Persaud reports. A study of whether there are different
forms of love has been launched by Dr Andreas Bartels
and Professor Semir Zeki from the Wellcome department
of neuroimaging at University College London. They have
attempted to unravel for the first time whether the love
between a parent and a child is the same as the emotion
shared by lovers.
But the evolutionary biologist has a more prosaic formulation
— the lifelong commitment serves to help a parents' genetic
material survive through to future generations. The passion
shared by two lovers serves a surprisingly similar function
— it facilitates mating and parenting — and hence again
is merely the selfish gene in action.
If we didn't love, then the species would simply never
get perpetuated, so maybe that is love's actual function.
But if all love boils down to, according to science, a
genetic prerogative being pursued through hard wiring
in our brains, then the neurological basis of love, like
the brain activity and hormonal responses which underpin
love, should theoretically share similar biological underpinnings.
To investigate this question, Bartels and Zeki, measured
brain activity in 22 mothers who viewed pictures of their
own infants and compared this with activity evoked by
viewing pictures of other infants with whom they were
acquainted for the same period.
In addition, they compared this activity to that when
other volunteers viewed their partner, a best friend and
an adult acquaintance to further control for familiarity
and friendly feelings.
The design of the experiment, using functional magnetic
resonance imaging, and just published in the journal Neuroimage,
allowed the scientists to determine the brain activation
related to maternal and romantic love while at the same
time controlling for the effects of familiarity and merely
The first intriguing finding is that there is a lot
of overlap between the brain areas activated during feelings
of romantic love for a partner and those involved in maternal
love for own children. The brain cells implicated
are the same as those we know become active whenever an
extremely rewarding activity is being undertaken.
These are precisely the same neurological locations
which are implicated when we consume food we like, take
drugs and when we are given monetary rewards. So love
is indeed like a drug.
However, the key result was that it's not just that certain
shared areas of the brain are reliably activated in both
romantic and maternal love, but also particular locations
are deactivated and it's the deactivation which is
perhaps most revealing about love.
Among other areas, parts of the pre-frontal cortex
— a bit of the brain towards the front and implicated
in social judgment — seems to get switched off
when we are in love and when we love our children, as
do areas linked with the experience of negative emotions
such as aggression and fear as well as planning.
The parts of the brain deactivated form a network
which are implicated in the evaluation of trustworthiness
of others and basically critical social assessment.
In other words, strong emotional ties to another person
inhibit not only negative emotions but also affect the
brain circuits involved in making social judgements about
The results, conclude Bartels and Zeki, suggest that
attachment involves a push and a pull mechanism — you
are pulled along by the strong sense of reward you feel
when you love.
But you are also pushed by a tendency not to objectively
see faults in the other person which might threaten love,
because circuits responsible for critical social assessment
and negative emotions are literally switched off.
So love really is blind and there is a biological basis
for the blindness.
This is a profound finding in the history of our attempts
to understand this most profound and powerful human emotion.
It means neuroscience finally explains why we can't see
the faults in our partners or children which others can
clearly perceive and as a result find our affection mysterious.
It also explains why we take so long to finally see
the flaws in those we idealise because of our love, and
which means we can end up choosing the wrong person to
commit to. The flaws only become apparent after our initial
ardour has cooled, allowing previously suppressed brain
areas to awaken to the reality of who we find ourselves
with the morning after.
But another key finding from the Bartels and Zeki study
is that there are important differences in the brain
areas involved in parental as opposed to romantic love
— so the two are not exactly the same.
For example, in romantic love a part of the brain towards
the base, called the hypothalamus, is specifically activated
and this area is implicated in pushing out chemicals which
mediate sexual arousal like testosterone and other sex
hormones. The hypothalamus does not activate when we
love our children.
Another difference was the part of the brain involved
in face processing and recognition appeared to
be more active in maternal compared with romantic love
and the authors of the study speculate that the rapid
rates with which the facial features of babies and young
children change and the importance of reading children's
facial expressions require a constant updating of the
face-recognition machinery, leading to heightened activity
in this part of the brain.
The fact that this face recognition area is not so active
in romantic love suggests our lovers are meant to not
change so rapidly in appearance, indicating perhaps a
neurological basis for suggesting we were meant to be
monogamous, or at least not sleep around so much that
our brains might find it difficult to recognise whom we
were waking up with the next morning.
Also, in romantic love, some parts of the brain possibly
implicated in what is termed "theory of mind"
seem to be more active compared with maternal love.
"Theory of mind" is about the notion that for
us to communicate effectively we have to develop a good
insight into what is going on in other people's minds
so we don't offend, and can work out how to please, others.
This finding suggests that an important part of the reward
we experience when we are romantically in love comes from
understanding that another is in love with us.
It is intriguing that this brain area doesn't seem to
be so important in parental love as it means that knowing
our children don't reciprocate our feelings for them
doesn't stop us loving them.
Now neuroscience is telling us that our brains dumb down
and rule our hearts so we rush into sex, then produce
children whom we also continue to care for no matter how
little they reciprocate.
It would seem that one of love's mysteries has at last
been cracked by science — if we used our brains to their
full capacity all the time and didn't deactivate clear
thinking and critical judgement, the species would never
have got off the ground.