The Psychopathic Chicken (and Other Lessons of Evolution)

An Interview with David Sloan Wilson

In the fifth chapter of his 2007 book Evolution for Everyone: How Darwin’s Theory Can Change the Way We Think About Our Lives, David Sloan Wilson writes:

“It turns out that something very similar to my desert-island thought experiment has been performed on chickens by a poultry scientist named William Muir.”

That probably sounds odd.

It will likely sound even odder when you find out what the desert-island thought experiment is: a set of three hypothetical situations to explore human morality through the lens of evolution.

But before we get to the morality of chickens, let’s provide a little context.

Wilson, a distinguished professor of biology and anthropology at Binghamton University in Binghamton, New York, is one of the primary advocates for an interdisciplinary application of the principles of evolution – the idea that Charles Darwin’s theory has much to tell us about humans and their cultures. He created his university’s Evolution Studies program and would like to see other colleges and universities embrace evolution similarly. “It’s sort of become my mission to incorporate this into higher education,” Wilson said last week in a phone interview.

His goal is first to make evolution accessible (and acceptable) by showing how the theory can be used to explain human behavior – a sensitive subject that had been largely off-limits until the past two decades.

He lays out his premise at the outset of Evolution for Everyone:

“This is a book of tall claims about evolution: that it can become uncontroversial; that the basic principles are easy to learn; that everyone should want to learn them, once their implications are understood; that evolution and religion, those old enemies who currently occupy opposite corners of human thought, can be brought harmoniously together.”

The aim of the desert-island morality example, then, is to see Darwin’s theory in human practice. As Wilson explains, it’s critical for people to understand that evolution isn’t just biology. It can explain why altruism exists in society against the apparent self-interest of its individual members.

“If you can’t address an issue like that,” he said, “then nobody’s going to accept the theory of evolution.”

And the reality is that a majority of Americans do reject evolution. Wilson notes in his book 54 percent don’t believe that humans developed from earlier species. “That is up from 46 percent in 1994,” he writes.

Humans want to be considered separate and different from other species; they do not want to be mere animal.

But Wilson said that evolution explains humans so well that the argument that we must exist outside of evolution has become untenable.

“It really is the case that evolution has become a set of basic principles that really explains life,” he said. “As that becomes ever more apparent and ever more powerful, then it’s clear that something’s got to give with respect to our own species. Tell me exactly why humans are an exception.”

Hence: chickens.

The conclusion that will surprise most people is that there’s altruism in hens, too, and there’s an evolutionary reason for it.

Wilson goes so far as to call evolution “a theory of everything.”

“All of this could be explained by these very simple principles,” Wilson said. “The theory of everything is, I think, what made evolution so remarkable to begin with.”

Basics of Evolution

If you’re a little rusty on high-school biology, evolution is based on the idea of natural selection.

As Wilson explains in Evolution for Everyone:

“Darwin’s theory of natural selection is like a recipe with three ingredients. We start with variation. Individuals such as you and I differ in just about anything that can be measured, such as height, eye color, or quickness to anger. Then we add consequences. The differences between you and me sometimes make a difference in our ability to survive and reproduce. Perhaps your superior size enables you to take my stuff or even kill me directly. Perhaps my inferior size enables me to survive the winter on less food. The details depend up on our particular traits and the environments we inhabit. The final ingredient, a sort of yeast that makes the recipe come to life, is heredity. For many traits, offspring tend to resemble their parents. …

“When the ingredients are combined, they lead to a seemingly inevitable outcome. As an example, imagine a population of moths that vary in their coloration (first ingredient). Some are more easily spotted and eaten by predators, removing them from the population (second ingredient). The offspring of the survivors resemble their parents (third ingredient), so the entire offspring is more cryptic, on average, than the parental generation. If we repeat the process over many generations, and if nothing else happens to complicate our story, the moths will become very hard for predators to spot. … They have acquired a trait that helps them to survive in their environment. In evolutionary parlance, they have increased their fitness and become well adapted.”

The Desert Island

Wilson wants to bring this evolutionary framework to the human realm, and then remind us that some of our “human” traits are present in other species.

On the human front, Wilson has the desert-island example, which deals with one area that evolution is supposedly ill-equipped to address: morality.

The knock on evolution is that it explains selfishness well – because that will supposedly enable a person to survive and reproduce better than selflessness – but it doesn’t seem to provide an explanation for goodness in society.

Wilson disagrees. “Evolution explains the full spectrum of behaviors, from selfishness to altruism, and those behaviors can either be adaptive or not depending on the underlying environmental situation – in this case, how individuals are grouped,” he said.

First, consider what might happen if a good person and an evil person are stranded together on a desert island. As Wilson writes: “The good person will become shark food within days.”

Second, consider what might happen with a group of good people on one island and evil people on another island: “The good group will work together to escape the island or turn it into a little paradise, while the evil group will self-destruct.”

Third, what might happen if one of the evil tribe is allowed to “paddle over to Virtue Island” – a hypothetical that comes closest to reality? That’s a little messier (just like our society), but the point is that Darwin’s theory is a lot more robust than most people give it credit for.

“Evolution should make us more selfish, to survive and reproduce better than our neighbors, not to help our neighbors survive and reproduce,” Wilson said. “But with just a little bit of thinking, you can show how the traits associated with goodness can evolve by a purely Darwinian process.

“Although it’s very fundamental that selfishness beats altruism within single groups, it’s equally as fundamental that altruistic groups beat selfish groups,” he continued. The advantage of goodness “resides at the society level.”

Wilson relays in his book that the “thought experiment” about humans on desert islands was replicated by that poultry
scientist, who tried to increase egg production in two ways: by breeding individually productive hens and by breeding hens from the most productive cages.

How did the individually productive hens fare? After six generations, he writes, there

“were only three hens, not nine, because the other six hens had been murdered. The three survivors had plucked each other during their incessant attacks and were now nearly featherless. Egg production plummeted during the course of the experiment, even though the most productive individuals had been selected each and every generation. What happened? The most productive individuals had achieved their success by suppressing the productivity of their cagemates. Bill [the poultry scientist] had selected the meanest hens in each cage and after six generations had produced a nation of psychopaths.”

Which leads Wilson to write:

“I can tell you with confidence that the eggs in your refrigerator are brought to you by good hens.”

“The traits associated with goodness … do exist in nonhuman species,” he said.

Stuck in Biology

Even though Wilson argues that evolution applies so naturally to so many areas of human and nonhuman life, it has largely been confined to biology for the past 150 years.

It shouldn’t have been that way, Wilson said. Even in the time of Darwin, “these simple principles are so explanatory. … When Darwin first came up with his theory, everyone knew that the consequences for our understanding of humans would be momentous, and yet for complex reasons, by the early 20th Century, evolution was restricted largely to biology and avoided for most human-related subjects. And that’s true to this day, as far as higher education is concerned. If you want to take evolution, you go to the biology department.

“Only recently has evolution spilled out of biology to be applied to our own species. Most of the developments are within the last 10 or 15 years.”

The problem, Wilson said, was that evolution was perceived as “very threatening” to human potential (because you’re stuck with your genes) and morality (because a simplistic understanding of evolution would seem to favor selfishness).

And evolution was used for political ends, such as Social Darwinism. “At the time, evolution became associated with certain political ideologies that more or less favored inequality,” he said. “It was used to justify British class society … , and it fed into colonialism.”

Culture’s democratic and egalitarian impulses “ended up rejecting evolution,” Wilson said.

He added that critics of evolution said the theory had “nothing to say” about learning and culture – aspects of humanity that were said to make it unique among animal species.

“Now it’s become obvious … that learning and culture … need to be understood from an evolutionary prospective,” Wilson said. “That is by no means an alternative to evolution.”

The Threat

Wilson’s premise of applying evolution to humans is a way of sidestepping the political controversy about the subject. He understands that supporters of creationism and intelligent design aren’t going to quickly abandon their views on the origins of humans.

“Objections to evolution have very little scientific traction,” Wilson said. “They have very strong political traction.” (Wilson also conceded: “There’s a lot of great and unanswered questions in evolution, don’t get me wrong.”)

But he doesn’t think the way to approach evolution is to argue. “Rather than grind away at that … to focus on understanding evolution in relation to human affairs actually cuts the Gordian knot in a sense,” he said. “As soon as anyone begins to understand that evolution is … explanatory, unthreatening, and useful … the first impulse is to embrace. Then that will solve the other [political] problem.”

Wilson is certainly adept at making science approachable to the general reader with clear language and good examples. “My Dad was a novelist [Sloan Wilson],” he said. “I’ve always been interested in people. … Part of me has always wanted to write a novel and has always been able to function in storyteller mode.”

He’s less successful at making evolution nonthreatening. At base, he’s trying to use logic and science to address core spiritual beliefs and an emotional need for purpose, and he only grudgingly admits that this might rub some people the wrong way.

For instance, he views religion from an evolutionary perspective, writing about the “adaptive fictions” and the evolutionary functions they serve. The sacred stories of our religions, he argues, do something but do not represent a truth. “Most enduring religions … are very highly organized to coordinate human groups as adaptive units and to ensure cooperation,” he said.

He said religions have a horizontal component (relationships with other people) and a vertical component (a relationship with God), and that the vertical part is “100 percent a social construction.” (Wilson is an atheist, and it should be noted that he has called atheism a “stealth religion” on his blog.)

When I asked him whether that tack – basically claiming that a religion’s myths are untrue but serve a purpose – he claimed that few people take offense. “That is indeed threatening to religious believers, but a smaller proportion than you might think,” he said.

“Ninety-five percent of what they [religious people] talk about when they talk among themselves has to do with the horizontal component: how to make people get along, how to transmit our best values to our children, and on and on.

“If we take all aspects of religion other than that [the vertical aspect], it’s amazing how much evolutionary theory can affirm those values” – cooperation, being part of something larger than ourselves, a path to enlightenment.

(This article originally appeared, in slightly different form, in the River Cities’ Reader.)