|
High-testosterone people reinforced
by others' anger, new study finds
Most people consider an angry expression to be among the most aversive facial signals humans can make. Yet a new study published by psychologists from the University of Michigan suggests that for some people an angry expression on another person’s face is so rewarding that they will readily learn behaviors that give rise to it.
Michelle Wirth and Oliver Schultheiss, the authors of the study, first took a saliva sample from participants in order to measure testosterone, a hormone that has been associated with dominance motivation. Next, participants worked on a learning task in which one complex sequence of keypresses was followed by an angry face on the screen, another sequence was followed by a neutral face, and a third sequence was not followed by any face. Participants who were high in testosterone relative to other members of their sex learned the sequence that was followed by an angry face better than the other sequences, whereas participants low in testosterone did not show this learning advantage for sequences that were reinforced by an angry face. Notably, this effect emerged more strongly in response to faces that were presented subliminally, that is, too fast to allow conscious identification. Perhaps just as noteworthy, participants were not aware of the patterns in the sequences of keypresses as they learned them. Thus, when high-testosterone participants showed better learning in response to anger faces, they were unaware of the fact that they learned anything in the first place and unaware of what kind of faces had reinforced their learning.
Michelle Wirth, the lead author of the study
and now a postdoc at the University of Wisconsin, Madison, explains
these findings as follows: "Better learning of a task associated
with anger faces indicates that the anger faces were rewarding,
as in a rat that learns to press a lever in order to receive a
tasty treat. In that sense, anger faces seemed to be rewarding
for high-testosterone people, but aversive for low-testosterone
people." And she adds: "Our finding contributes to
a body of research suggesting that perceived emotional facial
expressions are important signals to help guide human behavior,
even if we are not aware consciously that they do so. The human
brain may have built-in mechanisms to detect and respond to emotions
perceived in others. However, what an emotional facial expression,
such as anger, ’means’ to a given individual- whether
it is something to pursue or avoid, for example- can vary."
And Oliver Schultheiss, co-author of the study and an associate
professor at the University of Michigan’s psychology department,
muses: "It's kind of striking that an angry facial expression
is consciously valued as a very negative signal by almost everyone,
yet at a nonconscious level can be like a tasty morsel that some
people will vigorously work for." He also speculates that
the findings Dr. Wirth and he published in a recent
issue of the journal Physiology and Behavior may help explain
why some people like to tease other so much. "Perhaps teasers
are reinforced by that fleeting annoyed look on someone else’s
face and therefore will continue to heckle that person to get
that look again and again. As long as it does not stay there for
long, it’s not perceived as a threat, but as a reward."
Study finds US students more motivated to achieve, less power-hungry than German students (August 2006)
Are all people stressed out by a defeat or does it hurt some more than others? (April 2006) |
