get no argument from most people — especially on a cold
winter’s night — that hugs make you feel warm inside.
that good feeling protect your health?
past decade or so, researchers have sought to explain the
positive effects credited to the nonverbal gesture of human
connection. It comes alongside research that says chronic
stress is linked to shorter lifespans, higher rates of heart
disease and diabetes, depression and less effective immune
science takes two points of view: Hugs as a method of social
support, buffering the body from stress, and hugs as a
physiological experience that lowers blood pressure and levels
of the stress hormone, cortisol.
psychologist Sheldon Cohen of Carnegie Mellon University has
led new research that reports people who experience high
levels of social support and frequent hugs were protected from
a higher risk of getting sick when under stress. Published
recently Psychological Science, the 404 subjects in the study
— healthy people who were exposed to flu and cold viruses
— were monitored for 14 days for times of stress with other
people, number of hugs and amount of viral antibodies in their
blood (a sign of virus infection), and any mild or severe
symptoms of illness.
the mid-’80s, research by Cohen and others reported on the
ways a social network can help a person cope with life’s
stressful events, including interpersonal conflicts. By 1999,
research found that people who had stress from conflict with
other people and were exposed to the common cold virus had a
higher risk of being infected. The first part of the latest
CMU study was begun in 2000.
interest has been historically in social support," said
Cohen. "Our lab and others have developed a lot of
evidence that in people who have strong social support
networks, their network will buffer them from the effects of
stress. Less known is how that happens; how social support is
conferred to people." Generally, the CMU psychologist
explained, the amount of social support for a person has been
measured by asking people what support they have, not in what
people do to show this support. In the recent CMU study, hugs
were considered markers of close interpersonal relationships.
times of stress and conflict, that’s when support from
people in your life is important," Cohen said. "It
may make less difference in other times in your life."
other studies about nonsexual touch (have found) it can buffer
acute physiological markers of stress," he said. "We
wondered if it would work in the real world."
journal article says participants with low levels of social
support and more frequent interpersonal tension and conflict
were found to have a greater likelihood of being infected
after exposure to a virus. Both social support and hugs seemed
to offset the negative effect of tension and conflict in being
susceptible to getting sick.
you have high levels of conflict, you’re more likely to get
infected," Cohen said, "but you’re protected from
that if you have either high levels of social support or high
levels of hugs."
camp pursuing the study of the body’s physiological
responses to touch is Tiffany Field, director of the Touch
Research Institute at the University of Miami School of
Medicine. She said there is already well-known published
research showing that massage can improve the body’s immune
know that massage alters immune function," she said.
"There is data showing an increase in natural killer
cells (that destroy) bacterial, viral and cancer cells."
the literature shows that hugging between couples alleviates
stress," she said, naming 2005 research, also cited in
the CMU study, that showed that after hugging before a
stressful event, such as a test, cortisol levels in a person
was cautious about the CMU study design.
an amazing study," she said, referring to the multiple
blood samples taken and the steps to infect people with flu
and cold viruses. "We can’t draw blood from people who
aren’t ill," she said, wondering how difficult it would
be to get a university’s institutional review board to
approve a similar study today. She sits on her university’s
explained the study went through a rigorous review beforehand,
and the human subjects had to be in near-perfect health.
most recent study, 315 of the 404 participants became infected
with the virus they were exposed to — 78 percent. Of those,
127 had enough extra mucus and nasal congestion to be
considered clinically sick. There were far more days with
hugging, a median of 68 percent, than days with interpersonal
tension or conflict, a median of 7 percent.
disagreed with the study’s finding that stress was buffered
by hugging and social support because she saw no evidence that
stress caused infection, or that there was much helpful effect
from hugging. Neither stress nor hugs seemed to affect the
extent of illness, she said.
said the statistical interactions of the CMU study are
complex, but he theorized that because there were few days
reported with conflict, and many hugs on days without
conflict, perhaps they were giving protection from the stress
that came on a day with conflict.
supports research on the physiological and biochemical effects
touch, there is a cascade of events: stress hormones lowering,
natural killer (immune) cells increasing. Hugging is not just
studies at the Touch Institute involve pain, she said, but
results indicate the value of touch: "We have shown
moderate stimulating pressure leads to lower heart rate, lower
levels of cortisol, the brain is in the more relaxed state.
One would expect that hugging would also do that."
the difference in their two outlooks, Cohen said,
"Markers are useful to look at … but they are not
disease or disease processes. … Cortisol and epinephrine,
blood pressure are markers of activation of the body’s
response to stressors, but in and of themselves they aren’t
necessarily markers of disease or risk of disease."
should we be hugging more?
not ready to give advice," said Cohen, who continues to
look in detail on people’s behaviors in providing support to
other people. "Our studies are different than the real
world. We control for the exposure to the virus. … In the
real world, there is no controlling exposure.
you’re giving hugs during the flu season, you’re
increasing your exposure."
consider ourselves warned.