GRAY MATTER
Your Phone vs. Your Heart
Kristian Hammerstad
By BARBARA L. FREDRICKSON
Published: March 24, 2013
CAN you remember the last time you were in a public space
in America and didn't notice that half the people around you were bent
over a digital screen, thumbing a connection to somewhere else?
Most
of us are well aware of the convenience that instant electronic access
provides. Less has been said about the costs. Research that my
colleagues and I have just completed, to be published in a forthcoming
issue of Psychological Science, suggests that one measurable toll may be
on our biological capacity to connect with other people.
Our
ingrained habits change us. Neurons that fire together, wire together,
neuroscientists like to say, reflecting the increasing evidence that
experiences leave imprints on our neural pathways, a phenomenon called
neuroplasticity. Any habit molds the very structure of your brain in
ways that strengthen your proclivity for that habit.
Plasticity,
the propensity to be shaped by experience, isn't limited to the brain.
You already know that when you lead a sedentary life, your muscles
atrophy to diminish your physical strength. What you may not know is
that your habits of social connection also leave their own physical
imprint on you.
How much time do you typically spend
with others? And when you do, how connected and attuned to them do you
feel? Your answers to these simple questions may well reveal your
biological capacity to connect.
My research team and I
conducted a longitudinal field experiment on the effects of learning
skills for cultivating warmer interpersonal connections in daily life.
Half the participants, chosen at random, attended a six-week workshop on
an ancient mind-training practice known as metta, or "lovingkindness,"
that teaches participants to develop more warmth and tenderness toward
themselves and others.
We discovered that the
meditators not only felt more upbeat and socially connected; but they
also altered a key part of their cardiovascular system called vagal
tone. Scientists used to think vagal tone was largely stable, like your
height in adulthood. Our data show that this part of you is plastic,
too, and altered by your social habits.
To appreciate
why this matters, here's a quick anatomy lesson. Your brain is tied to
your heart by your vagus nerve. Subtle variations in your heart rate
reveal the strength of this brain-heart connection, and as such,
heart-rate variability provides an index of your vagal tone.
By
and large, the higher your vagal tone the better. It means your body is
better able to regulate the internal systems that keep you healthy,
like your cardiovascular, glucose and immune responses.
Beyond
these health effects, the behavioral neuroscientist Stephen Porges has
shown that vagal tone is central to things like facial expressivity and
the ability to tune in to the frequency of the human voice. By
increasing people's vagal tone, we increase their capacity for
connection, friendship and empathy.
In short, the more
attuned to others you become, the healthier you become, and vice versa.
This mutual influence also explains how a lack of positive social
contact diminishes people. Your heart's capacity for friendship also
obeys the biological law of "use it or lose it." If you don't regularly
exercise your ability to connect face to face, you'll eventually find
yourself lacking some of the basic biological capacity to do so.
The
human body - and thereby our human potential - is far more plastic or
amenable to change than most of us realize. The new field of social
genomics, made possible by the sequencing of the human genome, tells us
that the ways our and our children's genes are expressed at the cellular
level is plastic, too, responsive to habitual experiences and actions.
Work
in social genomics reveals that our personal histories of social
connection or loneliness, for instance, alter how our genes are
expressed within the cells of our immune system. New parents may need to
worry less about genetic testing and more about how their own actions -
like texting while breast-feeding or otherwise paying more attention to
their phone than their child - leave life-limiting fingerprints on
their and their children's gene expression.
When you
share a smile or laugh with someone face to face, a discernible
synchrony emerges between you, as your gestures and biochemistries, even
your respective neural firings, come to mirror each other. It's
micro-moments like these, in which a wave of good feeling rolls through
two brains and bodies at once, that build your capacity to empathize as
well as to improve your health.
If you don't regularly
exercise this capacity, it withers. Lucky for us, connecting with
others does good and feels good, and opportunities to do so abound.
So
the next time you see a friend, or a child, spending too much of their
day facing a screen, extend a hand and invite him back to the world of
real social encounters. You'll not only build up his health and empathic
skills, but yours as well. Friends don't let friends lose their
capacity for humanity.
Barbara
L. Fredrickson is a professor of psychology at the University of North
Carolina, Chapel Hill, and the author of "Love 2.0: How Our Supreme
Emotion Affects Everything We Feel, Think, Do, and Become."