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08/24/2005
Personality
The August 15 issue of Newsweek featured an article by Pat
Wingert and Martha Brant titled “Reading Your Baby’s Mind”.
The article describes research directed at finding out what goes
on in the minds of very young babies only a few months old. It
seems that these little guys and gals have a lot more going on
than expected. In fact, they have some pattern recognition
capabilities that exceed those of adults or even slightly older
children. I was surprised to learn that a baby at 3 months or less
can not only recognize a picture of its mother but can also
recognize its mother in a photo that has been cut up into pieces
and scrambled. Yet, as the baby becomes older and accustomed
to everything in its place, this ability is lost.
The prevailing view had been that a baby’s early life is a chaotic
time spent trying to mimic things that it sees and learning the
most basic emotions. However, babies are more sophisticated
emotionally than was thought. For example, researcher Sybil
Hart at Texas Tech University has performed one experiment
hundreds of times that demonstrates jealousy at an early age. A
mother and her 6-month-old baby are brought into a room and
the baby is placed in a high chair. Hart and the mother engage in
a conversation about a children’s book, paying no attention to the
baby. Typically, the baby just looks around, seeming rather
bored. Then Hart leaves and brings in a doll, hands it to the
mother with instructions to cuddle and play with the doll, still
ignoring the baby.
In almost every case, the baby suddenly perks up and pays close
attention to this new development. Soon, the baby becomes
quite disturbed by all the attention paid to another “baby” and
starts to cry, often emoting so strongly that it turns beet red and
the experiment is concluded with appropriate soothing by the
mother. This type of experiment shows clearly that the baby is
showing jealousy, with the emotional outburst being easily
spotted and easy to interpret.
What about more subtle emotions or reactions? Over the years,
scientists have become familiar with babies’ reactions and their
meanings. For example, by combining observed attention spans
with how long a baby stares at something new or, in some cases,
whether the baby turns away, can be interpreted as indicating
interest or surprise, fear or fascination, etc. Now we have more
sophisticated methods such as brain scans, computerized tracking
of eye movements and MRI to see how the baby’s responses
compare with those of adults.
Let’s see how the simple technique of watching how an
individual reacts to something new or unexpected can be used to
study another primate, the lemur. The lemur is that wide-eyed
critter found on the island of Madagascar and is a lower form of
primate than the monkey. Researchers were interested to see
whether or not the lemur has the ability to count. Unfortunately,
I’ve lost the reference to this study but do remember, hopefully,
the pertinent details.
The researchers used “magic” to test the young lemurs, which
have a very short attention span. The scientists used the old trick
of showing the lemur a group of 1, 2 or 3 balls, then covering
them and then removing the cover to reveal either none, the same
or one more ball than previously. They then measured the time
spent by the lemur staring at the new situation, concluding that
more time spent looking at it conveys that the lemur is surprised
that a missing or extra ball is present. If it’s surprised, that
indicates that the lemur has a rudimentary ability to count, at
least up to 2 or 3.
Other animals have demonstrated more advanced counting
abilities and emotional behaviors. Yesterday, I golfed with a
veterinarian and we were discussing the famed African grey
parrot Alex, which I’ve mentioned on a number of occasions in
these columns. Alex has an extensive vocabulary and an
amazing ability to interact with people and respond intelligently
to questions. The vet and I talked about how Alex seems to have
a sense of humor, toying with new people by purposely giving
the wrong answers to questions until reprimanded.
Some scientists criticize researchers who ascribe human
characteristics or emotions, “personality” if you will, to an
animal. They apparently feel that this credits the animal with
more intellect than is warranted. I tend to believe that some
critters have a lot more on the ball than we think. An article in
the July 29 issue of Science titled “Strong Personalities Can Pose
Problem in the Mating Game” by Elizabeth Pennisi ties in with
this personality issue. The article notes that a quarter of a
century ago, the late Stephen J. Gould and Richard Lewontin
stirred up the evolutionary biology crowd with a proposal that
maladaptive traits could persist if they carried with them some
sort of benefit to the animal. (Incidentally, I found in Gould’s
book “I Have Landed” the statement that he considered Lewontin
the smartest man he ever met.)
Take an animal’s personality (if you don’t like the term
personality, call it a “behavior syndrome”). What kind of
possible advantage is it when a female fishing spider has such an
aggressive personality that, sensing the gentle tap on the water by
a male fishing spider seeking a romantic rendezvous, she eats the
poor guy before he gets any further? Certainly, from the male’s
standpoint, that female’s hostile personality is a maladaptation of
the worst kind. From the female’s standpoint, she just killed a
potential mate and a chance to pass along her genes to another
generation. On the other hand, her aggressive personality has
resulted in her seeking out and devouring many other tasty
tidbits, which plumped her up to the point she became attractive
enough to warrant a tap on the water from a potential suitor. Her
hostile demeanor also serves to help her defend her territory.
Andrew Sih, a behavioral ecologist at the University of
California, Davis, is one of those promoting the idea of Gould
and Lewontin. Sih suggests that some animals are stuck with
their dispositions and don’t have the means of modifying them.
Another behavioral ecologist, J. Chadwick Johnson of the
University of Toronto, Scarborough, followed the behavior of
some female fishing spiders from birth to adulthood. He found
that the females that were more aggressive during childhood
grew to be plumper than their less aggressive contemporaries.
The aggressive females were also bolder in responding to
predators. When Johnson mimicked a bird tapping on the water,
all the spiders dived to get away but the aggressive females came
to the surface first, putting themselves in greater danger if the
bird was still there. The same aggressive females were also more
likely to snack on males come a courting.
A reversal of roles occurs with an insect known as the water
strider. Sih split up male striders into groups of whose
personalities ranged from mild mannered to very aggressive. He
then monitored the successes of the various groups in their
mating. The females didn’t really care for the more aggressive,
macho males and would avoid them and their fellow macho
companions. As a result, the more aggressive male striders fared
poorly in their mating endeavors, both individually and as a
group. The aggressive males didn’t have the capacity to modify
their personality to fit the occasion. This certainly isn’t the case
with our own species, for which both males and females can be
quite adaptive in the quest for a mate.
“Whilst this planet has gone cycling on according to the law of
gravity, from so simple a beginning endless forms most beautiful
and most wonderful have been, and are being evolved.” So ends
Darwin’s “Origin of Species” (quote taken from Gould’s book).
For the sake of the male fishing spider, let’s hope the female
evolves to lose her taste for potential mates.
Allen F. Bortrum
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