Nature and Nurture

In chapter 11 of Animal Behavior, John Alcock postulates that the dichotomy of nature or nurture is a misconception. According to his view, the idea of a purely environmentally determined behavior makes no sense because ultimately,  in order for the environment to affect our behavior, there must be a change in our genetic material. Otherwise, what would the link between environment and our behavior be? Behavior has its substrates in our brain, so there must be a regulation of genes if we argue that the environment can affect our behavior.

He argues as well that not every environmental factor can affect our behavior. The reality is that we are sensitive to a specific range of stimuli. These environmental stimuli are the ones that we can detect using our sensory system. This idea implies that our genetic material “prepares” us to be shaped by certain environmental factors. The metamorphosis of bees is a clear example of this concept. Bees transition from being “nurses” (younger bees) to being “foragers” (older bees). Scientists discovered that nurse bees can be induced to become “foragers” if they are put in an environment where older foragers are absent. Later, it was discovered that the gene activity varies in the brains of nurse bees and foragers. Many of these genes were transcription factors, which code for proteins regulating the activity of other target genes.

Conversely, the higher the number of older foragers in a colony, the lower the number of young nurse bees that have an early transition into foragers. Scientists were puzzled by how the number of foragers in the environment could transform the behavior of younger bees. Eventually, it was discovered that foragers produce a chemical (ethyl oleate) that inhibits young bees from transitioning into foragers. Therefore, the more foragers in a colony, the less likely younger bees are to transition to foraging status because they are being inhibited by this chemical.

Alcock’s honey bee example shows that behavior, at least in this case, is not purely genetically determined because bees’ behavior is reshaped by the interaction of environmental chemicals and intrinsic genetic factors. It is important to notice that the genes that elicit the forager behavior in bees were activated only when the appropriate environmental factors were present. Gene Robinson summarized this idea by saying: “DNA is both inherited and environmentally responsive”.

In my opinion, this is an interesting concept, particularly coming from a school where I hear all the time that everything is a social construct. Is gender nothing but a purely environmentally determined behavior? What are the genetic factors that drive us here and there? The factors that make us respond in a way or another to our social experience? Will we ever find these neural substrates in our brain? What makes us female, male, or other? I share Alcock’s opinion and I think that we do not live in a mutually exclusive dichotomy of nature and nurture. Instead, we are the product of a beautiful balance of factors. Something unique that has come to be thanks to what we carry inside us and what we take from our environment. We are evolving all the time.

– H. C