Body of Thought: How Trivial Sensations Can Influence Reasoning, Social Judgment and Perception
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Body of Thought: How Trivial Sensations Can Influence Reasoning, Social
Judgment and Perception
Fleeting sensations and body movements hold sway over what we feel and how
we think
By Siri Carpenter | December 23, 2010 | 5
Why do we look up to those we respect, stoop to the level of those we
disdain and think warmly about those we love? Why do we hide dirty secrets
or wash our hands of worries? Why do we ponder weighty subjects and feel a
load lift after we have made a decision? Why do we look back on the past and
forward to the future?
Such turns of phrase, invoking a physical reality that stands in for
intangible concepts, might seem like linguistic flights of fancy. But a
rapidly growing body of research indicates that metaphors joining body and
mind reflect a central fact about the way we think: the mind uses the body
to make sense of abstract concepts. Thus, seemingly trivial sensations and
actions-mimicking a smile or a frown, holding smooth or rough objects,
nodding or giving a thumbs-up-can influence high-level psychological
processes such as social judgment, language comprehension, visual perception
and even reasoning about insubstantial notions such as time.
The implications seem almost preposterous. Holding a warm cup of coffee will
make me view others more warmly as well? Entering a Windex-scented room will
bring out the Good Samaritan in me? Holding a heavy clipboard while
responding to a survey will give the issues at hand more gravitas? As
far-fetched as such sensory non sequiturs may seem, the evidence for
"embodied" or "grounded" cognition is persuasive. "The empirical case is
becoming increasingly overwhelming," says psychologist Lawrence Barsalou of
Emory University. "Cognition is emerging, to a significant extent, from all
these things-like warmth, cleanliness and weight-that we used to think were
irrelevant to cognition."
Recent research suggests, for example, that the flexing of our facial
muscles does not just reflect our emotions but is necessary for our
experiencing them. Even less logically, our minds link morality to
cleanliness, a connection that underscores just how desperately our
processing of abstractions hangs on physical attributes. Even more jarring,
people represent the concepts of past and future in a bodily code that
includes direction of movement and perception of space. And our concept of
space itself depends on mental simulations of the movements necessary to
span that distance.
Such bizarre interactions imply that our brains do not really differentiate
between our physical interface with the environment and high-level, abstract
thought. The idea that the mind is anchored to the body's actions and
surroundings "gives us a much better way of trying to understand how people
work-our social behavior, our emotional lives, our cognitive lives," says
psychologist Arthur Glenberg of Arizona State University. Indeed, armed with
this new conception of how thought works, we can now get a grasp of our own
feelings, opinions and actions by looking beyond our minds to our bodies and
the world around us. Such a perspective can point us toward actions that
change the way we think and learn.
Challenging Dogma
Since the 1960s most cognitive scientists have likened the neural machinery
responsible for higher cognition to a freestanding computer, separate from
the brain areas that are responsible for bodily sensation and action.
According to this idea, the brain receives input about sights, smells,
sounds, and so on from the body's sensory and motor systems, but then
converts those raw data into disembodied symbols and rules, in much the same
way that a computer converts every piece of information-the color red, a
photograph of your grandmother, the word "love"-into zeros and ones. On
these symbols, stripped of their raw, physical origins, the brain performs
the many complex calculations that we call thought.
Beginning in the late 1980s, however, a few scientists challenged the view
that the body is just an input-output device for the brain. They suggested
that instead, higher cognitive processes are grounded in bodily experience
and in the neural systems that govern the body. In this view, the brain's
low-level sensory and motor circuits do not just feed into cognition; they
are cognition.
Back then the idea had little scientific backing. "We were totally
ridiculed-people didn't take it seriously," Barsalou recalls. But by the
late 1990s the evidence started trickling-then pouring-in. Just in the past
few years studies have shown that holding a hot cup of coffee or being in a
comfortably heated room warms a person's feelings toward strangers; that
striking an open, expansive "power pose" prompts people to make bolder
decisions; that wearing a heavy backpack makes hills look steeper; that a
water bottle looks closer when you are thirsty; that moving objects upward
versus downward speeds recall for positive versus negative memories; and
that sitting on a hard chair turns mild-mannered undergraduates into
hard-headed negotiators.
That the mind relies heavily on the body for information should not be
surprising. After all, the body is our only real tether to the world-all the
knowledge you acquire, you get through your senses. Close ties between the
body and thought make sense from an evolutionary perspective, too. Over
millions of years many cognitive scientists believe, our increasingly
powerful cognitive abilities piggybacked on existing neural systems that
evolved for simpler, physical tasks such as visual detection or spatial
navigation.
According to this view, thinking is reliving: I cannot reflect on last
summer's trip to the Grand Canyon without recruiting some of the same brain
cells that recorded the sight of its majestically striped walls. I cannot
process the plot of a novel without simulating the sensations the text
describes nor judge the height of the hill ahead of me without mentally
climbing it. "The brain simulates real experience in order to make sense of
the world," Barsalou says.
Facial Feedback
Anyone who has sweated a job interview or clenched a fist in anger knows
that living an emotional experience is a physiological event. This
phenomenon is reflected in the idioms we call on to describe our feelings:
your heart sinks, your stomach flips, you jump for joy, you are mad enough
to spit nails. "Emotional states are associated with a tendency to action,"
says psychologist Paula Niedenthal of Blaise Pascal University in France. As
a result, people do not say, "I was so mad that I just . sat there."
In addition to the physiological systems that regulate heart rate, sweating
and body movement, the triggering of emotions involves the activation of at
least some of the 20 or so muscles of the face that control emotional
expression. That fact raises the question of how that peripheral physiology
affects thought: Can merely changing the configuration of a person's facial
muscles affect how that person thinks about emotion?
Results of a now classic study led by psychologist Fritz Strack, now at the
University of Würzburg in Germany, show that the simple act of making a
facial expression affects both how we feel and how we interpret emotional
information. Strack and his colleagues found that people rated Far Side
cartoons as funnier when they were holding a pen between their teeth,
without allowing it to touch their lips (a pose that activates muscles used
for smiling), than when they were holding a pen between their lips (which
prevents smiling). Those findings indicate that the face sends important
feedback to the brain, which it then uses to interpret information about the
world.
Many researchers, including Niedenthal, believe that the brain cannot fully
think about emotion without reenacting, or physically simulating, that
feeling. In a 2009 study she and her colleagues used electromyography to
measure facial muscle activity and found that reading emotional words while
considering their meaning triggered the same subtle muscle activity that
people show when experiencing those emotions. Words that typically evoke
disgust, such as "vomit" and "foul," stimulated increased activity in the
facial muscles involved in curling the upper lip, wrinkling the nose and
furrowing the brow. Words that connote anger, such as "murder" and
"enraged," also provoked activity in the muscle that furrows the brow. And
words that connote joy, such as "smile" and "delighted," set off the muscles
responsible for raising the cheeks and crinkling the eyes into a smile.
In other words, the researchers concluded, when people reasoned about
emotional concepts it caused them to simulate a bodily experience of the
emotion, evidence that the reasoning and the muscle activity are linked. "If
someone asks me to go see a scary movie," Niedenthal says, "I can
reexperience the feeling of fear I have had while watching such movies and
decide whether that is an experience I want to seek out or avoid. Otherwise,
how could I know?"
What happens when people's ability to simulate specific emotional
expressions is blocked? In 2009 neurologist Bernhard Haslinger and his
colleagues at the Munich University of Technology gave participants Botox
injections to the forehead, temporarily paralyzing the muscle that is
responsible for frowning. The treatment muted activity in the amygdala, a
key emotion center, while participants were attempting to mimic unhappy
expressions but not when they were mimicking happy faces. The results
suggest that by thwarting muscle activity, Botox treatment somehow jammed
the neural circuits needed to fully process negative emotion. A 2010 study
led by Glenberg and University of Wisconsin-Madison graduate student David
Havas bolsters that conclusion, showing that participants who underwent
Botox treatment for frown lines were subsequently slower to comprehend sad
and angry sentences but not happy ones.
Clean Hands, Pure Heart
The body plays an equally important role in reasoning about abstractions.
Consider, for example, the link between physical cleanliness and moral
purity-the relation that Shakespeare's Lady Macbeth felt so desperately as
she tried to scrub away her sins. In a 2006 study psychologists Chen-Bo
Zhong of the University of Toronto and Katie Liljenquist of Northwestern
University gave research participants the same opportunity (though under
less murderous circumstances). They first asked participants to recall doing
ethical or unethical deeds, then gave them an ostensibly unrelated
word-completion task. Those who had remembered unethical behavior were more
likely than those who had summoned up ethical behavior to generate
cleansing-related words such as "wash" and "soap," rather than words such as
"wish" and "step." In a follow-up experiment, 75 percent of people who had
recalled unethical deeds later selected an antiseptic wipe (rather than a
pencil) as a parting gift, compared with only 37.5 percent of people who had
brought to mind ethical deeds.
On the face of it, that the human psyche would tie physical cleanliness and
moral purity defies logic-any rational person knows that a bar of soap will
not absolve wrongdoing. Yet clearly, the bond runs deep. Water-purification
rituals, for example, are a part of most of the world's major religions.
Zhong and Liljenquist speculate that the connection may stem in part from a
basic cognitive need to root abstract qualities in bodily experience and in
part from an evolved disgust toward unclean foods. That primal disgust, some
researchers believe, has expanded to take on broader cultural meanings, so
that moral violations pose the same kind of threat as physical impurity.
The presence of that connection is obvious in the language we use to
describe moral violations-we speak of keeping dirty secrets and yearning for
a clean conscience. Our language further suggests that moral cognition is
tightly bound to the specific body parts responsible for ethical
transgression-say, the mouth for swearing or the hands for groping. "In
natural language, when people swear, we say they have a dirty mouth,"
observes Spike (Wing Sing) Lee, a psychology graduate student at the
University of Michigan at Ann Arbor. "If someone steals something, we might
say that they have sticky fingers."
The specificity of such sayings led Lee and psychologist Norbert Schwarz,
also at Ann Arbor, to wonder whether people actually project immoral
behavior onto specific body parts. In a 2010 study they asked research
participants to role-play a scenario that required them to tell a malevolent
lie using either voicemail or e-mail, then rate the desirability of several
consumer products. Lee and Schwarz found that people rated hand sanitizer
more highly after lying via e-mail rather than voicemail and rated mouthwash
more highly after lying via voicemail rather than e-mail. Thus, people did
seem to make a subconscious, nonverbal connection between a part of their
body and the specific type of unsavory deed.