Dr. Steve Suomi : Genetic and Environmental Connection

The research that we do in this setting, and in our smaller social groups
allows us to look at both genetic and environmental factors, and how they interact
as monkeys go from infancy, through the childhood years, into adolescence and
into adulthood, and whether the changes that we see have
correlates in their genetic background. Whether
the differences in the dominance hierarchy that we can see very dramatically
here, are doing things like affecting their gene expression
as well as affecting levels of their stress hormones, and levels of their neurotransmitters.
And we can take the data
that we get just watching these monkeys interact in undisturbed fashion,
and then go to our smaller groups
and start making manipulations. What happens when monkeys are
moved from one group to another? What happens when monkeys are
formed into new groups, and they are getting together for the first time?
What happens when they get to an age of, both out in the wild here,
or in our smaller groups when
mother starts paying less attention to them, because she is getting ready to have
her next offspring? Most of the
youngsters, when this happens, about six or seven months of age,
go through a little bit of stress, because suddenly they're
not getting all of the attention they used to, and they have to learn how to cope with other
individuals in their group. We're very interested not only in
mother/infant relationships, but what kind of friendships these monkeys form
as they are growing up, because when they are in the equivalent
of childhood years, they will spend several hours every day in active social play.
And we know that this social play, far from being frivolous, is actually
provides a forum, where every behavior they're going to need to use
in their complex social world when they become adolescents and adults
can be practiced, perfected, and developed
long before those behaviors actually have to become functional. And we can see
individual differences in this. How about monkeys who play a lot,
do they have greater brain growth? Do they have
lower levels of cortisol? What about these monkeys who are aggressive?
In the wild, and in groups like this, what happens is other monkeys don't
like them because they play too roughly, and they start avoiding them
and these monkeys start becoming isolated even though they are living in a social group.
That affects their serotonin metabolism, and now we're
seeing to what extent these kinds of differences are showing up in terms of gene expression.
So, underlying this interest in individual differences
at the behavioral or emotional level are underlying
biological factors, that in turn, can be traced back to
genetic differences as well. So, because we can get
all these different sorts of data from the same individual, and then compare
them for that individual in one social situation
as opposed to a different social situation, we can get an integrated picture
of what underlies personality, and how flexible it
is, how maliable it is, if it can be changed for the better.
Or, in some cases does it start to deteriorate?