A new book called The Encultured Brain: An Introduction to Neuroanthropology by Daniel H. Lende and Greg Downey introduces a novel approach to my discipline of anthropology, and in fact I think this approach has relevance to all of the sciences that study human beings. As the name suggests, the gist of neuroanthropology is to study the interaction of human culture and human brains. Once one begins to do this, one of the oldest and most fruitless questions in the human sciences begins to dissolve. This question is: which is more important in determining human behavior, nature or nurture? As soon as one starts looking at how the brain interacts with culture, it becomes clear that it’s time to retire this question. What we need to try and understand is how nurture becomes nature and how nature is shaped by nurture.
Oddly, the best way I can explain this is to point to something I read recently about a different species. In a wonderful book about dogs entitled (appropriately) Dogs, Raymond and Lorna Coppinger point out that the ten-fold growth of a puppy’s brain is after birth due almost entirely to connections between the original cells (rather than growth in the original number of cells). They write: “Of all the brain cells present at birth, a huge number are not connected or wired together. What takes place during puppy development is the wiring pattern of the nerve cells.” (p.111) And—this is the crucial point—what gets wired depends on what is happening in the environment. The Coppingers make this point to explain why—and if you think about it this is rather intriguing—dogs can be trained to guard sheep from predators rather than eating them. Basically, if a dog grows up around sheep as its brain is forming, it will come to regard sheep as its friends. And that behavior cannot be unlearned. It is biological, imprinted, but this behavior is not determined by genes alone. Rather, it is epigenetic, a product of the dog brain and the environment working together. The implication is, in the Coppingers’ words once again, “Understanding brain growth should dispel the nature/nurture controversy once and for all. It is never, ever either nature or nurture, but always both at the same time.” (p. 113)
Humans, of course, have much more complex brains than dogs. However, epigenetic processes are also important for understanding how humans adapt to their environments. Even such basic and seemingly physical processes such as seeing, balance, and the course of illness may be conditioned by the environment within which the brain develops. This means that cultural factors become part of the physical makeup of the mind. And this process does not cease after the brain is fully mature. Unlike dogs, old humans can learn new tricks. What neuroanthropology brings us is an appreciation of how deeply human learning can be rooted. Lende and Downey write, “Neural systems adapt through long-term refinement and remodeling, which leads to what we see as deep enculturation. Through systematic change in the nervous system, the human body learns to orchestrate itself. Cultural concepts and meaning become neurological anatomy. “(p. 37)
In short, how we are nurtured-throughout our lives creates not just ideas and values, but influences our brains at the cellular level. Our nurturing becomes part of us, becomes nature. In the coming years, I predict that the implications of this fact will have revolutionary implications for such matters as the treatment of mental illness, education, policies for addressing poverty, and intercultural understanding.