Two recent articles [1, 2] in the New York Times took on the old “Nature versus Nurture debate” in the context of the new “parent wars” spurred by Amy Chua‘s book “Battle Hymn of the Tiger Mother“. Too bad no one told the authors of these articles that the “Nature versus Nurture debate” was over — or at least has dramatically shifted gears — within scientific circles.
Perhaps the science editors of the New York Times ought to be reading Scientific American, specifically Frans de Waal‘s “The End of Nature Versus Nurture“. This 1999 article concisely summarizes what I believe is consensus among most biologists: that the additive treatment of genes and environment implied in the “nature versus nurture” concept is wrong. A person’s traits are not some part genetic and some part environmental: everyone’s traits are the simultaneous result of genes and environment. It is now well understood that it is the interaction of genes and environment that produces traits, so “nature” and “nurture” are best represented as multiplying to produce traits. There is no “either-or” when you multiply, and complex interactions can arise from different combinations of genes and environments.
To say that we understand that traits arise from the interaction of genes and environment is not to say that we understand how traits arise from this interaction. In some cases we can understand how genes and environment interact, and we tend to focus on the most simple and detectable examples. But for any trait that we are interested in — such as behavioral traits — understanding the complex interaction between genes and environment is not easy. This is because most interesting traits are the product of numerous genes, and in order to understand how those genes contribute to traits we need to understand their complete interaction with a complex environment. Before we can pronounce that a particular trait is “highly genetic” we actually need to show that it produces the same trait in all environments, and this is not just hard to show but also highly unlikely. If “genetic determinism” means traits are produced exclusively by genes, genetic determinism is dead. If “genetic determinism” means that all traits are influenced by genes, genetic determinism is alive and well. David Sloan Wilson has a fabulous chapter in his Evolution for Everyone book entitled “How I Learned to Stop Worrying and Love Genetic Determinism” that makes clear how cloudy most people’s views are on this subject.
What frustrates me about articles like these recently published in the New York Times is that they perpetuate an out-dated way of thinking that strongly colors people’s understandings of themselves and their fellow human beings. Looking at the person next to you and asking “what part of their personality arose from her genes and what part of her personality arose from the environment she experienced?” is to ask a nonsensical question. The correct question, and a question whose answer is far harder to obtain, would be: “How have this person’s genes interacted with her environment to produce her personality?”. Getting the public to shift their thinking on this issue would do a lot to clarify how we should be assessing both genetic potential and environmental influences.Articles, Development, Gene by Environment Interactions, Genetics, Human Nature, Web