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Chimps wear personalities on face
By Bruce Bower
In chimpanzees, as in humans,
faces are personality billboards,
a new study suggests.
People can usually tell whether a chimp acts dominantly
and is physically active just by
looking at a picture of the ape’s
expressionless mug, says a team
led by psychologist Robert Ward
of Bangor University in Wales.
Consistent with earlier evidence from other researchers,
Ward and colleagues reported
last year that volunteers can also accurately detect whether people are extroverted, emotionally stable, agreeable and
imaginative by looking at pictures in which
the people have neutral expressions.
Extroversion in people and dominance in
chimps both relate to assertiveness and
sociability, and both partly derive from an
individual’s genetic makeup.
An ability to discern key personality
traits via facial structure evolved more
than 7 million years ago in a shared ancestor of people and chimps, the researchers
propose online January 18 in Evolution
and Human Behavior.
“The fact that chimpanzee facial signals can be read by humans suggests that
our ability to read others’ faces accurately
is not solely acquired through culture, but
is part of an evolved system,” Ward says.
That’s an intriguing hypothesis in need
of testing with composite images that digitally combine many pictures of the same
chimps into single mug shots, remarks
psychologist and chimp researcher Lisa
Parr of Emory University in Atlanta.
Composites minimize slight variations
from one photograph to another in lighting, skin hue, head angles and other
factors that can create different personality impressions of the same individual.
In previous studies, Ward’s team had
A study indicates that people can usually tell if
a chimp is socially dominant, like the one shown,
from a picture of its emotionally neutral face.
participants evaluate composite images
of people, but technical difficulties have
stymied attempts to create composite
chimp faces. Anatomical landmarks used
to create composite images, such as the
jaw’s position, are difficult to measure
on chimps’ hairy faces. Also, composites
smooth facial textures, so chimps’ faces
look blurry rather than hairy.
Many grade-schoolers put
up with disliked classmates
affiliated elementary school, Olsen and
colleagues report online January 13
in Personal Relationships. That figure
exceeded the percentage of relationships
in which each child dislikes the other.
One-quarter of the 2,313 classroom
relationships studied consisted of two-
way friendships. Remaining pairings
mainly included cases in which one child
acknowledged another as a friend or as
especially disliked, but the second child
expressed no opinion about the first.
Not so surprisingly, aggressive and
socially troubled third- to sixth-graders
often believed they were friends with kids
who disliked them, the researchers say.
On the other side of the equation, kids
who got labeled as buddies by a classmate
they disliked got along well with others
and had plenty of genuine friends.
Unbalanced friendships have received
little attention from researchers, Olsen
notes. Previous research has focused on
pairs of children who say that they mutually like or dislike each other.
Kids’ friendships
not all so mutual
In the brutal social world of elementary
school, friendship can be deceptive. It’s
relatively common for children to consider as friends classmates who admit
disliking them but seem affable on the
surface, researchers say.
“The common prevalence of unbalanced relationships, where children
believe themselves to be friends with
someone who actually dislikes them,
is surprising,” says James Olsen, a psychologist at the University of Memphis
in Tennessee.
Unbalanced relationships comprised
12 percent of third- to sixth-graders’
classroom relationships in a university-
