Nature, Nurture, and Pretty Much Everything Else

I’m guessing that anyone reading or listening to this essay knows what I mean by the “nature-nurture debate,” that is, the driving need of some to attribute human behavior to either biology (that is genes) or nature (culture, what we absorb and learn). Those in Western culture have embraced this dualistic approach as a way of figuring ourselves out, and we also commonly see nature and nurture as opposing forces and want so very much to know which is the stronger influence. Also, many feel the nurture part, that is, culture, elevates us above other animals, a stance that appears to be of great importance to some people. This debate will never be solved, no matter how long we wonder about it, because the assumed strict dichotomy that opposes what we were born with against what we acquire over a lifetime is fundamentally flawed.

This so-called nature/nurture debate has a long, loud, and not so illustrious past. When Frances Galton first invented the division in 1869, he was a believer of the nature side, that is, that what you were born with explained everything. That perceptive fit nicely with the biases of the British educated and wealthy classes, who wanted to believe that they were predestined from birth to be the privileged class, which also meant they should be in charge of the world. Galton was so enamored of this that he also embraced the theory of eugenics, which claimed that the human race overall could be “bred” smarter by eliminating the less able to get rid of those so-called less than optimal humans. The result, eugenicists believed, would be an accomplished, thriving society. Lost in that position was the obvious fact that nutrition, education, and all forms of either privilege or degradation and discrimination have dramatic effects on the body and mind. A group of academics added their two cents to this philosophy around the turn of the 20th century and applied Charles Darwin’s theory of evolution by natural selection to human processes such as economics and politics, suggesting that only the “biologically” strong survive and so they were designed to be at the top of the heap. Called “Social Darwinism,” this approach was just another attempt to sustain upper-class privilege by using biology as evidence, or so they claimed.

A biological or “best genes” perspective ingratiated itself in Western culture and fueled some of the worst moments in human history. To cite only a few examples, eugenicists felt that only white people were genetically well-endowed and they should run the world. For example, Aryan Germans (a loosely defined term) during World War II felt they should be in charge of the world because they had “better” genes. That kind of genetically hierarchical thinking was also used against the waves of immigration into the United States from Ireland (1840 to the 1920s) and Italy (the 1880s to the 1920s); those immigrants might have been white-skinned, but they were considered somehow genetically inferior to those who were already Americans. The history of black Americans is a testament to the ugliness of dismissing, murdering, or enslaving one group of humans by claiming they were genetically inferior to whites. And today in the United States, that ugly and scientifically misinformed embrace of so-called genetic ideals has reared its ugly head once again, placing white, and specifically white males, at the pinnacle of creation and deserving of all the power and financial success, with everyone else lower on the human hierarchical ladder, using some amorphously conceived idea of genes as an excuse for bigotry.

And yet, the idea that genes can determine our fate has repeatedly been challenged by science and our own eyes. One of the most famous and reasonable oppositions came from Franz Boas, the “Father of American Anthropology,” who had emigrated to the U.S. from Germany in 1887 after spending time with the Inuit of Baffin Island. Boas became a professor of anthropology at Columbia University in New York, where he had the opportunity to see the flood of European immigrants into the U.S. and hear all the negative complaints about these intruders who were considered “lesser than.” Part of the whining was the complaint that “those people” were undesirable because they were biologically inferior to other Americans and could not be changed because that inferiority was “genetic” and therefore permanent. Fed up with complaints that immigrants were, by their very nature, inferior to white Americans, Boas began a scientific study of how the body, presumably fixed by genes, actually changes with the environment, that is, with better nutrition and less stress. Starting in 1908, Boas collected physical measurements of immigrant populations in the U.S. over the span of four years. He discovered that the length of time an immigrant spent in the U.S. changed their cranial shape and their height, among other measures, which introduced the idea that the skeleton, clearly formed by a genetic program in the womb and grown by a genetic plan after birth, was subject to change depending on the environment. Good nutrition could easily affect childhood growth patterns, for example. Boas’s point was that genes might produce traits, even ones we think of as immutable, but in fact the environment could modify them.

The nature/nurture debate should have dissolved as a “thing” at that point, but it didn’t, because those who thought they had “good genes” and were destined for wealth and power kept bringing it up to use against the less fortunate whenever it suited their political or social aims. Then this debate about biology and culture returned in force in the 1970s in the halls of Academica. But the science of genetics and the template of evolution by natural selection had progressed, and so the questions about nature and nurture became more sophisticated. An attempt at parsing animal behavior into separate planes of biology or cultural exploded in 1975 when Biologist Edward O. Wilson published Sociobiology: The New Synthesis. That book was a sweeping accounting of what was known about behavioral patterns across many species from ants to monkeys, and Wilson made the case that behavior, not just biology, evolved by natural selection, making a mess of a strict nature/nurture debate. After Wilson, it was not enough to just observe and describe the behavior of other animals; we had to come up with evolutionary hypotheses to test why that behavior had evolved in that species. And this was a dramatic change in approach. Before this time, my field, primatology, had been a descriptive endeavor, but by the time I was working on my Ph.D. thesis in the late 1970s, the switch was in place, and I had to approach monkey behavior with an evolutionary eye. That approach was successful on many fronts: we were able to propose reasonable scenarios for the evolution of broad patterns of nonhuman primate behavior such as territoriality, kin relations, the appearance of hierarchies, social relationships, and the struggle for survival. We might not have been able to connect some strand of DNA to some behavior, but we could point out that “many do this,” and if we had evidence of their individual reproductive success (how many infants they produced) we could make the claim that a behavioral pattern (e.g. gaining high rank) probably had a biological and therefore genetic substrate and was “selected for” by the evolutionary process.

But imposing that template on humans rather than other animals was problematic because people often think deeply before they act, and they are sometimes strongly influenced by what others expect, say, and do. And they are enveloped in culture, most often defined as “what we acquire at birth,” which makes untangling human behavior an almost impossible task. But a new subdiscipline called evolutionary psychology tried to ask if natural selection had favored some behavior for some reason. Unfortunately, their work focused primarily on Western culture, so they failed the “universal” test, which was necessary to make any evolutionary claims. Also, most of what they looked at were issues about mate choice, in the sense of what people want in a mate as opposed to what they end up getting. And they always seemed to be missing the essential evidence of how their pattern of behavior under study improved someone’s reproductive success. If that act cannot in some way be connected to some universally successful trait that passes on more genes, it is evolutionarily meaningless. Also, no one has been able, even now, to connect a gene or set of genes to any individually defined behavior. We might know that a behavior, such as thinking about choosing a mate or moving your arm, is the result of chemical-electrical signals that emanate in the brain, making it a biological act, but so far that roadmap doesn’t connect with particular genes.

But this biology/culture conflict, and a lack of consensus, has also produced some very interesting research based on human genes. Anthropologists eventually plotted human migration in the past, making connections among populations, and constructed DNA-based trees to clarify the path of human fossil evolution and our genetic relationship to other living primates. And over the next many decades, geneticists did, in fact, discover the genes underlying various diseases such as Sickle Cell Anemia, Huntington’s, and Thalassemia. Other studies found a connection between a particular gene and the “risk” of expressing a condition such as breast and colon cancer, or Alzheimer’s disease. But these studies also leave so much unexplained, and that fact seems to escape those who saw genes as the key to everything.

The reality is that pinning down how much humans are influenced by their genes remains elusive because the mechanisms and paths of biology are just so tangled. For example, even when we know the particular genes underlying a disease, sometimes a condition might never bloom, that is, be expressed. In the same way, that effect can be variously expressed. For example, someone with an extra 21st chromosome is said to have “Down’s Syndrome” with indicative physical and behavioral changes. But some with Down syndrome are highly functional, while others are less so. A presumed genetic source for various types of behavioral and mental conditions is also used these days to legitimize conditions such as Autism, chronic depression, or schizophrenia and we label them as diseases although no one has identified any specific genetic mechanism at work and instead turn to family trees in hopes of plotting that condition into the past, assuming it was “passed down,” like brown eyes. The sentence “depression runs in my family” is now common, but no one can point to a specific strand of DNA that might cause that depression. All that lineage talk is just inference until someone isolates the specific genes for whatever. But still, the “disease” label is an assumption that biology, not culture, is at work, and it has crept into the conversation lately. The role of genes in human behavior and expression can be determinative, but they can also just be one small part of a story, or inconsequential. We just don’t know enough at this time.  

To cultural anthropologists, such a genetic or evolutionary approach to human behavior was, and is, anathema. Humans, they understand, are indeed animals, but not like other animals because we are influenced by culture, that is, our made-up and learned atmosphere. For these scholars, culture, not biology, is the main driver of human thought and behavior, and they explore individual cultures, their formation, history, economics, and social life for answers to why certain groups of people do what they do. To culturally oriented anthropologists, taking an evolutionary or biological stance seems like a behavioral straitjacket that allows no free will and no way someone could change their condition or rise above what they had been dealt at birth. And yet this happens every day around the world as people change, move, emigrate, learn, and achieve. In other words, grasping for an evolutionary explanation for patterns of behavior in humans seems like just another kind of Social Darwinism set out to eliminate the possibility of human choice because natural selection is in charge.

And yet, this other side of the nature/nurture debate also has its inconsistencies and blank spaces. First of all, we have little idea what nurture (or environment) really means, or what we should include in nurture or culture. “Culture simply means the knowledge and habits acquired from others,” says primatologist and expert on chimpanzee behavior Frans De Waal. Others say culture is that which is learned, and that is a very broad palette. It includes what a person experiences over a lifetime from the moment of birth to the hour they die, what they see, hear, feel, and understand, and the social, emotional, and intellectual rules they live by. “Culture” means the very belief systems that run just about every aspect of our lives. But culture is so intangible and amorphous that we don’t really recognize our own cultural template until we meet a person from another culture and realize they think and act so differently, that their assumptions about life are completely different. 

And yet, even with the frustration of never really getting any answers to the nature/nurture debate, we still keep at it; it seems a “forever” argument. And that’s because what humans, especially Western humans, are looking for is someone or something to blame. I’ve heard parents of adopted children claim that it was their fabulous parenting (nurture) that produced a well-functioning child, or that the child’s heritage (genes) was at fault when things didn’t turn out so well. In biological families, some of the positive or negative blame gets sticky since the kids share some genes in common. But still, parents with difficult kids seem to always say “they were born that way” (meaning different or damaged) offered up as an excuse, which makes no sense because the child’s genes come from them. Successes, on the other hand, are most often attributed to “hard work” and “ambition,” and imply choices that are conscious and purposefully made and have nothing to do with genes or biology.

Perhaps it’s no surprise that Westerners can’t let go of this continuous harangue about nature and nature because Westerners, as De Waal points out, love a dichotomy, what he calls “Western dualism,” with nature and nature envisioned as opposing forces. Other cultures are much more comfortable with the possibilities of many sides to a situation and expect various reasons for a thought or behavior. For example, in many cultures, ancestors play a vibrant role in meaning and action. Other cultures also give agency to witches, sorcerers, shamans, and various gods, as substantial agents behind what we think and do. The West also suffers from believing in only one God, and we have trouble accepting more than one religion, especially one that has a different prophet or a different sort of deity. And so, we turn to genes because we need to believe that something tangible and describable, something fundamental and knowable, must be behind our thoughts and actions. But the equation is so complex and so individually variable that looking back over a lifetime doesn’t in any way solve the puzzle of nature versus nurture because that dichotomy is fundamentally flawed in the first place. Searching for clean lines separating nature and nurture is a specious endeavor. Human thought and behavior are entwined with everything in life, and there is no separating the two.

In fact, some recent scholarly approaches have attempted to add various other threads to this previous dichotomous debate. For example, Biological Anthropologist Jonathan Marks says that Western culture has incorrectly elevated the role of genes to the position of a “cultural icon” that can explain everything about humans. But our bodies and minds are also deeply affected by development, meaning our nutritional options and opportunities, and all kinds of physical and mental stressors. Dolton Conoly, professor of Sociology at Princeton University, thinks we should also consider how the genes of others might affect us. Interacting with others, we absorb their behavior as part of our environment, and he thinks such interactions change us. In other words, beyond what we eat and how we exercise, our social lives might be another sort of nurture that is making us who we are. And Oxford anthropologist Harvey Whitehouse suggests that all humans have three biases that are the “building blocks” of our “common inheritance”—conformism, religiosity, and tribalism. We might think these tendencies are “cultural,” that is, learned, but Whitehouse suggests they are inherent, part and parcel of who we are.

These scholars are only a few of the ones thinking and writing about the complexity of human behavior who have abandoned the traditional nature versus nurture dichotomy for more complex approaches to figuring out why we act and think as we do. We might be approaching a time in which the nature/nurture debate is abandoned and replaced with a more inclusive, and decidedly more messy explanation: Human behavior and thought are brought to you by everything in life, everything we see, hear, touch, and react to. It is what we are born with as well as who we hang around with. It is what we eat and drink, and how much we move our bodies, and every single thing that culture throws at us. It is about being born formed by a particular packet of genes, and then growing up, learning, and dealing with life every step of the way until we die.