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December 4, 2000

Understanding Human Natures

Arri Eisen is a senior lecturer in biology and director of the
Emory College Program in Science and Society.

Is it possible that teaching evolution might help prevent racist incidents or the overuse of antibiotics? That an understanding of biologic and cultural co-evolution can help humanity address some of its deepest problems?

In his ambitious Human Natures, Paul Ehrlich, a leading thinker in the field of evolutionary biology for nearly 40 years, makes provocative arguments supporting such claims.

Here’s a reflective book in which an elder statesman sits back and tries to figure it all out. Ehrlich does an impressive job of it. He joins the ranks of Stephen J. Gould, Steven Pinker and Richard Dawkins as great synthesizers of ideas and information on evolution.

Imagine addressing questions like: Why do we walk upright? What are language and consciousness and how did they evolve? Why do we go to war?

From cavemen to Columbine, Ehrlich takes on this enormous task with an effective and informal writing style and—with an excellent background on genetics and evolution—makes Human Natures accessible to a general audience and enjoyable to read.

Ehrlich’s central thesis is that each of us has a unique human nature; there is not one singular human nature. Ehrlich argues that, for example, saying aggressiveness or going to war is “just human nature” has dangerous implications (analogous to excusing a particular behavior because someone “has the gene” for it) and is plain wrong.

Each of us has some chance of making rude gestures at the car that wouldn’t let us into the next lane or bashing our brothers in the face when they won’t share. That chance, though—and this is the essential point—depends on our unique combination of genetic predispositions which have been strongly shaped by our environment: culture, experience, language, geography, social grouping. All this together composes our distinct human natures.

Maybe it’s just my nature, but I am much more drawn to Ehrlich’s synthesis of how we become who we are than to the “selfish gene” ideas of Dawkins.

Dawkins and his followers say, basically, that everything can be explained by what’s best for the genes; we are merely a convenient means for the genes to get themselves passed on to the next generation.

Ehrlich builds a strong case for his more reasonable assertion that what we become is a combination of genes and culture—a co-evolution between the two. And it is culture, Ehrlich argues, that is the dominant component in this equation.

A significant portion of Human Natures examines how an understanding of evolution and our evolutionary history is useful for helping productively approach major societal problems. For example, the evolution of our minds was driven by vision. If all the junk we dumped into the air turned the sky green, we probably would have cleaned it up long ago. Most of our biologic evolution took place in social groups of 100 or so; now most of us live with millions.

Cultural evolution can happen much faster than biologic evolution. Our ability to do has far outpaced our ability to understand what we are doing and its implications. But all is not lost. Human beings are uniquely able to carry out what Ehrlich calls “conscious evolution.” Using as one example the scientific community’s response to the threat of nuclear war, Ehrlich posits that we can intentionally change our evolution.

This view and most others expressed in the book are less reductionist, more humanist, than those expressed by many evolutionary biologists. Not surprisingly then, Ehrlich criticizes the cultural evolution of our universities—the places we turn to for answers to society’s problems—into disciplinary fiefdoms.

At Emory, we encourage interdisciplinary approaches to problems as significant and important enterprises in the academic arena. Ehrlich says such approaches are necessary for the survival of our civilization. Diverse scholars must share perspectives and bring substantial conversation to the public on issues such as environmental sustainability, genetic engineering and population growth.

Ehrlich reinforces Ernst Mayr’s claim that Charles Darwin had more influence on science and human thought than perhaps any other individual of the last century.

When I told a friend about Human Natures, he groaned and said, “Look, evolution’s great, the foundation of biology, but why do people feel it necessary to use it to explain everything?” I told him the desire among people, especially when they’re older, to synthesize and understand the world is probably, at least for some, human nature.


Back to Emory Report Dec. 4, 2000