The Domesticated Ape: Explaining the Paradox of Virtue and Violence in Human Evolution

The Goodness Paradox by Richard Wrangham“The test of a first-rate intelligence is the ability to hold two opposed ideas in the mind at the same time, and still retain the ability to function.” – F. Scott Fitzgerald

The human mind is plagued by a host of biases, and one of the most prominent is the “false dilemma” fallacy. This fallacy occurs whenever two choices are presented as the only options when a spectrum of possible choices exist, and is especially prevalent in debates regarding human nature.

Human nature is often presented as either innately good and corrupted by society (following Jean Jacques Rousseau) or as innately bad and civilized by society (following Thomas Hobbes). As you can imagine, the truth is much more complicated.

In The Goodness Paradox, Richard Wrangham presents a more nuanced view of human nature—informed by decades of research in primate behavior and evolutionary psychology—that accounts for the complex interplay between genetic predispositions and cultural forces that compel both good and evil behavior.

The first thing to note is that humans are, by the standards of nature, abnormally nonviolent. Our closest evolutionary cousins, chimpanzees, are 100 to 1,000 times more violent and aggressive than humans. Even bonobos, which are known for their tameness, are also quite a bit more aggressive compared to humans. Chimpanzees have the tendency, for example, to brutally and fatally attack, as part of a group, lone chimpanzees in neighboring territories at alarming rates. And, as Wrangham wrote, “one hundred percent of wild adult female chimpanzees experience regular serious beatings from males.”

So humans are, relatively speaking, extremely nonaggressive in terms of violence within a group or local community. At the same time, humanity has the potential to produce death on unimaginable scales during times of war. Hundreds of millions of people died as a result of the two world wars, and countless others have died in wars throughout history. There seems to be a paradox involving our abnormally nonviolent behavior in local groups and our extraordinarily violent behavior in war. How can we account for this?

Wrangham is proposing that the answer to this paradox lies in the difference between proactive and reactive aggression. Reactive aggression is an emotional reaction based on anger or fear in response to an immediate provocation or threat. Chimpanzees display high levels of reactive aggression whereas humans do not.

Proactive aggression, on the other hand, is cooly planned and coordinated to achieve some type of internal or external goal. It is not a response to an immediate provocation but rather a planned attack for the achievement of a stated goal. Humans display the highest levels of proactive aggression in nature.

To illustrate the difference between reactive and proactive aggression, Wrangham writes:

“The anthropologist Sarah Hrdy noted that to pack hundreds of chimpanzees into close quarters on an airplane would be to invite violent chaos, whereas most human passengers behave sedately even when they are crowded. As Dale Peterson observed, however, intense screening is needed to ensure that a secret enemy will not carry a bomb on board. The contrast illustrates the difference between our low propensity for reactive aggression and our high propensity for proactive aggression.”

Humans, due to their unique ability for language, abstract thinking, and emotional control, are not only equipped for greater proactive aggression, they have actively used it throughout history to select for individuals with lower reactive aggression. Our evolutionary history therefore predisposes us to both high levels of proactive aggression and to low levels of reactive aggression.

The “execution hypothesis” demonstrates how. According to Wrangham, the execution hypothesis “proposes that selection against aggressiveness and in favor of greater docility came from execution of the most antisocial individuals.”

Our ancestors developed coalitions of a large number of egalitarian males that would eliminate bullies and other miscreants (with high levels of reactive aggression) by killing them. This transformed human societies from alpha-male dominated hierarchies to egalitarian coalitions that did not tolerate selfish or aggressive behavior. With an enhanced ability to gossip, plan, and coordinate attacks, egalitarian groups became more powerful than single alpha-males. This selection for more docile humans occurred over thousands of generations to produce self-domesticated modern humans.

The evidence for this is of two types. The first is that virtually every known ancient culture engaged in capital punishment, and that ancient remains show signs of violent injuries. As Wrangham wrote:

Capital punishment was present in all the earliest civilizations, from Egyptian, Babylonian, Assyrian, Persian, Greek, and Roman to Indian, Chinese, Inca, and Aztec. It happened not only for violent crimes but also for nonconformism (as is Socrates’s case), for minor felonies, and even some heartbreakingly trivial matters such as malpractice in selling beer (according to the Code of Hammurabi), or stealing the keys to one’s husband’s wine cellar (according to the laws of the early Roman Republic).”

The second line of evidence is indirect, but is part of a larger phenomenon known as the “domestication syndrome.” Charles Darwin first noticed that domesticated animals displayed certain characteristics that differed from their wild ancestors, such as tameness, floppy ears, white patches of fur, and juvenile faces with smaller jaws. Modern genetics has since discovered that all of these traits may be the result of changes to neural crest cells that are responsible for both physical characteristics and for changes in the adrenal glands (resulting in less fearfulness).

The interesting thing is that humans, compared to our evolutionary forebears, show these same physical and behavioral traits shared by other domesticated species. Modern humans are smaller (with smaller jaw lines), tamer, and more docile compared to our distant ancestors (and Neanderthals), just as dogs are tamer and smaller than wolves and bonobos are tamer and smaller than chimpanzees.

We know that humans can selectively breed silver foxes for tameness that turns them, behaviorally speaking, into dogs. Wrangham’s revelation is that we did the same thing to ourselves by “selecting” for docility in humans by killing aggressive individuals over thousands of generations. Our tendency for proactive aggression resulted in a reduction in reactive aggression.

This seems to adequately resolve the paradox. One might wonder if our enhanced intelligence and ability to cooperate would explain the difference, and that reactive aggression is simply suppressed as a result of our superior emotional control. But higher intelligence and social cooperation does not seem to adequately explain the docility and lack of aggression we witness in most humans.

This has moral implications as well. While Wrangham recognizes that genes do not determine behavior, and that we are not prisoners to our biology or to anything that is “natural,” our evolutionary past and self-domestication explains much of our moral behavior. In an environment where egalitarian coalitions have the power to kill nonconformists, reputation suddenly becomes of paramount importance. This explains a host of our behaviors and emotions, such as guilt, shame, and embarrassment, and why we all care so much about what others think of us and why we feel the desire to punish wrongdoers (a tendency not found in chimpanzees).

And so we arrive at a disturbing conclusion. Our nonviolent tendencies from reduced reactive aggression is the result of our increased capacity for organized and planned violence toward those we deem to be different. As Wrangham writes, this makes our moral priority going forward quite clear: finding ways to reduce our capacity for organized violence and war.


The Goodness Paradox: The Strange Relationship Between Virtue and Violence in Human Evolution by Richard Wrangham