Suomi – maternal buffering

Well, because we’re able to determine the genetic background of our monkeys and describe, and indeed, control their environmental histories we are in a position to see whether there are so-called pure genetic effects and whether there are so-called pure environmental effects. And indeed, when we do straight forward analyses like those, yes we find that most, many of the things that we’re studying, both behaviorally and physiologically, have highly heritable components and they clearly can be modified. These patterns can clearly be modified by differential early experiences. But when you run analyses that take both into account, what stands out is that pure genetic effects and pure environmental effects are the exception rather than the rule. And instead what we see is interactions between these effects so that individuals who have the same genetic background but grow up in different environments turn out quite differently and individuals who have different genetic backgrounds but are in the same, grow up in the same environments, also have very different outcomes.  

And indeed, these fall into some very interesting patterns and perhaps the most interesting pattern is a pattern of what we call maternal buffering. Over and over, for many behavioral and physiological variables, we find that individuals who carry genes that would put them at risk to have less optimal outcomes under relatively poor environmental circumstances; when those same at-risk monkeys grow up with good mothers they turn out perfectly normally or in some cases even better than the so-called normal Rhesus monkey developmental trajectory.  

And so we’re impressed by the fact that good mothering can allow individuals who carry genes, to carry genes that would otherwise put them at risk to continue to carry those genes and indeed, pass them on to the next generation but with no obvious behavioral problems. On the other hand, if something happens that compromises, in nature, a mother’s ability to take care of her kids that have, carry those genes, then a variety of problems will emerge. And so this is why we talk in terms of maternal buffering as one of the primary driving forces behind the gene-environment interactions that we’re able to observe and document.