EVILICIOUS: Cruelty = Desire + Denial (16 page)

The economist Samuel Bowles and his colleagues provide a different argument against the proposed similarities between human and chimpanzee killing. Unlike Ferguson and Sussman, Bowles is entirely sympathetic to biology but sees fundamental differences in the pattern of human killing and warfare. To explain these differences he invokes two important attributes of human societies that have only weak parallels in other species: large-scale cooperation with unrelated others from the same group, together with hatred, symbolic labeling, and the motivation to hurt all others outside the group. These two factors, what Bowles calls
parochial altruism
, may have paradoxically generated both greater levels of cooperation within groups and higher rates of warfare between groups. Those groups with the best cooperators acquired the greatest resources and experienced the fewest losses due to cheaters and other morally corrosive rogues. This power and inward-looking favoritism led to self-defensive emotions and behaviors, ultimately leading to lethal aggression toward those with different beliefs and values. Thus parochialism and altruism co-evolved, hand in hand, breeding prejudice as a result of group safety. We saw an earlier example of this in
chapter 1
where I discussed the results of Fehr’s studies of fairness in children: kids of all ages were more likely to share with familiar children from their school than strangers from another school. Thus, evolution handed us a capacity to be discriminating altruists, a capacity that breeds hatred for those not like us, which recruits violence toward those outside the inner sanctum.

Bowles’ analysis is interesting and consistent with my explanation of how we evolved the capacity for gratuitous cruelty. Certain aspects of our capacity to harm others emerges as an incidental byproduct of other capacities, and once this dynamic emerges, the combination of these capacities can evolve and change. What Bowles’ analysis misses, however, is the fact that parochial altruism could well be true, and so too could our shared capacity for killing with chimpanzees. As noted above, rates of killing among chimpanzees and several small scale societies are comparable, and so too are the costs and benefits to attackers and victims. This argues in favor of a shared history and a shared adaptation. It does not mean that all aspects of killing in humans are similar, or that the human mind froze in a chimpanzee state with regard to its capacity to kill. There are differences that reveal the signature of evolutionary change.

Unlike the lethal attacks by chimpanzees that are restricted to cases where groups attack lone victims, primarily from neighboring groups, we wreak havoc on a massive scale, with one on one, many against many, and one against many, including victims within and outside our core group. Unlike chimpanzees, even our young children have an appetite for violence that can be nurtured, as evidenced by the brutality of child soldiers around the globe. Unlike chimpanzees, individuals will sacrifice themselves for an entire group as evidenced most recently by suicide bombers. Our minds also generate ideological reasons to motivate violence at extraordinary scales — again, think of suicide bombers taking their lives for a God, as well as the reward of an idyllic afterlife. And when our minds break down, or when we are afflicted with particular disorders early in life, we are capable of experiencing bizarre appetites for violence, including the joy of eating the flesh of murdered victims. These novel and unanticipated ways of harming others are the result, at least in their origins, of new hardware that evolved only once in the history of this planet: a brain wired to combine and recombine thoughts and emotions.

I will explain this idea in three steps, starting with a description of our brain’s special design. I then turn to a discussion of how our brain’s design incidentally enabled our species alone to punish moral transgressors and feel good about it. I conclude with the incidental birth of version 2.0 of harming others, a form of lethal aggression that was both extreme and enjoyable — evilicious.

Creative combinations

To appreciate the significance of the human revolution in brain engineering, consider an example of a different form of intelligence that evolved for one, highly adaptive function: to brain wash and then destroy another organism for purely selfish reasons. This is the kind of example that caused Darwin to marvel over the nature of design, doubt the beneficence of God, reflect upon the cruelty of nature, and ponder the problem of evil.

In Brazil, there is a parasitoid wasp of the family
Braconidae
that lays its eggs inside a particular species of caterpillar. Once the larvae are fully developed, they hatch out of the caterpillar. But this isn’t the end of the caterpillar’s role as surrogate caretaker. Once the larvae hatch, they are treated to an unprecedented level of care from the caterpillar who, Gandhi-like, foregoes all eating and moving to protect its adopted young, including violent head-swings against any intruder.

The wasps’ ability to hijack the caterpillar’s brain is an exquisite example of evolutionary engineering, as well as selection for a specific function. Think of all the pieces that had to come together for the wasp to subvert the caterpillar into a parental slave: finding the right host, laying eggs inside of the host without getting caught, designing eggs that will develop inside the host and then emerge alive, and rewiring the host’s brain so that it sticks around and defends the young of another species. This highly adaptive and myopic pattern of thinking runs throughout the animal kingdom and across different contexts: birds that feign injury to deter predators from their nest, but deceive in no other context; cheetah mothers who demonstrate to their cubs how to bring down prey, but never provide pedagogical instructions in other relevant domains of development; and chimpanzees that use stones to crack open palm nuts, but never use these tools for any other function, including as weapons against dangerous neighbors or potential predators. In each of these cases, the capacity evolved to solve a specific problem and does so spectacularly well. But there is little to no evidence that these capacities are used to solve any other problem.

Like other animals, we too are equipped with adaptive capacities that evolved to solve particular problems. Unlike other animals, however, these same adaptive specializations are readily deployed to solve novel problems, often by combining with other capacities — a fluidity of intelligence that has been noted by others, especially the philosopher Daniel Dennett and the archaeologist Steven Mithen. Like wasps, we deceive, manipulate and parasitize others, often cruelly. But unlike wasps, this capacity is not restricted to one type of victim and one context. As long as the opportunity for personal gain is high relative to the potential cost, we are more than willing to deceive, manipulate, and parasitize lovers, competitors and family members. The same point applies to teaching and tool use, capacities that are virtually unconstrained in terms of context. Teaching occurs whenever a knowledgeable individual identifies an ignorant individual, whether the context is formal as in schools and organized sports, or more casual, as when parents inform their children about social norms, children share the latest apps with each other, and married couples educate each other about their likes and dislikes. When we invent a tool, it may start out with a clear and narrow function, but this in no way limits its use. A hammer is designed for tapping nails and removing them, but can also be used to break hard things, pry open stuck things, and hurt those we don’t like if nothing better is available. In each of these cases, the range of functions is virtually limitless because of our brain’s capacity to repeatedly combine thoughts and emotions from different domains of knowledge. The combinatorial options are vast. What changes in the brain enabled us, but no other species, to engage in this fluid thinking?

Dennett, Mithen and others who have addressed this question have often pointed to the critical role of language. They suggest that our capacity to create and string together words to express our thoughts provides the glue to connect up different ways of feeling, seeing, hearing, smelling, and remembering. That language provides this kind of glue is undebatable. That language enables fluid thinking also seems undeniable. But language itself is a system that is built up out of different and highly connected parts of the brain, and thus, different kinds of knowledge. When our brain composes a sentence, either before it is articulated or if it is simply formed as part of an internal monologue, the system that is required to form words must connect with the system that structures words into grammatically appropriate sequences. If we are motivated to communicate this expression, it is necessary to connect with yet another system of the brain, the one responsible for the library of gestures that turn linguistic thoughts into linguistic sounds or signs that others can understand. Language is therefore an example of our brain’s capacity to connect up different brain systems, but it is only one of many that enabled our fluid thinking.

To understand what changed in the brain, it is useful to paint a few broad-stroke comparisons, and then narrow in on the details. We know, for example, that brain size changed dramatically over the course of our evolutionary history, ultimately reaching three times the size of a chimpanzee’s brain with the appearance of the first modern humans, some 100-200,000 years ago. From the archaeological evidence, we can infer that some aspect of the internal workings of the brain — not simply size — must have changed at about the same time in order to explain the appearance of a new material culture of tools with multiple parts and functions, musical instruments, symbolically decorated burial grounds, and cave paintings. Before this period, the material culture of our ancestors was rather uncreative, with simple tools and no symbolism. The new material culture was heralded by a mind unlike any other animal. No other animal spontaneously creates symbols, though chimpanzees and bonobos can, to some extent, be trained to use those we invent. No other animal creates musical instruments or even uses their own voice for pure pleasure. No other animal buries its dead, no less memorializes them with decorations; ants drag dead members out of their colony area and deposit them in a heap, though this is driven by hygiene as opposed to ceremonial remembrance and respect. Only a species with the capacity to combine and recombine different evolved specializations of the brain could create these archaeological remains. This period in our evolutionary history marked the birth of our highly inter-connected, combinatorial brain.

The brain sciences help us see the fine details of this new species of mind. The comparative anatomists Ralph Holloway, James Rilling, and Kristina Aldridge have analyzed brain scans and skull casts of humans and all of the apes: chimpanzees, bonobos, gorillas, orangutans, and gibbons
⁴⁸
. These species had a common ancestor approximately 15 million years ago. As distinctive species with a shared heritage, they represent a considerable diversity of mating systems, dietary preferences, use of tools, group size, life span, locomotion style, communication system, aggressiveness, and capacity for cooperation. Thus, gibbons are primarily monogamous, live in small family groups in the upper canopies, swinging and singing to defend their territories, never use or create tools, are omnivorous, restrict cooperation to within the family group, and show little aggression. Gorillas live in harem societies, knuckle walk on the ground, are folivores or leaf eaters, rarely use or make tools in the wild, show aggression primarily between harems, communicate with a diversity of sounds, and show limited cooperation even under captive conditions. Chimpanzees are promiscuous, omnivores who hunt for meat on the ground and in the tree tops, create a diversity of tools that are culturally distinctive between regions, communicate with a diversity of sounds, are lethal killers when they confront individuals from a neighboring community, and are cooperative especially in competitive situations. Despite this diversity, nonhuman ape brains are much more similar to each other than any one is to a human brain. What changed since we split off from our ape cousins is both the overall geometry of the brain in terms of the relative size of different components, as well as the connections both within and between these components. Some of the most spectacular changes evolved within the frontal and temporal lobes, as well as their connections to other areas of the brain involved in the control of emotion and stress. These circuits play a critical role in decision making, self control, short-term memory, social relationships, tool use, language, and yes, violence.

For detail, and further evidence of combinatorial thinking, we turn to imaging studies of healthy adults, maturational changes in children, and brain damage in patient populations
⁴⁹
. Consider tool use, an example I briefly referred to above. Though a wide variety of nonhuman animals use tools, only humans create tools that combine different materials, have multiple functioning parts, can be used for functions other than the one originally designed, and function in the context of survival, reproduction, and leisure. These are the signature properties of a combinatorial brain. When we look at the material culture of the most sophisticated animal tool user — the chimpanzee — we see tools that use a single material, have only one functional part, were designed for this function, and the function set is strictly limited to survival or reproduction. Something as simple as a pencil, beyond the chimpanzees’ wildest imagination, consists of multiple materials — rubber, wood, lead, metal — was designed for writing but can be used for poking a hole or creating a drumbeat, and has two functional parts — lead for writing, rubber for erasing. When you put a human subject in a brain scanner and record activity during observations of tool use, what you see is an orchestrated coordination between different and connected brain regions. There is activity in regions carrying out spatial analyses, motor behavior, goal directed assessments, and object recognition, and much of this activity is fed forward to the frontal areas for storage in working memory as well as judgment and evaluation. And as we learned in the last chapter, when we see other humans as tools or mere objects, we lose the connection to those brain areas involved in representing others as social creatures with beliefs and desires. This suggests that our fluidity involves both creating and breaking connections between different brain areas.