We humans take so much of reality for granted that it is often difficult to recognize which phenomena even require explanation. This is especially true of human behavior, as Steve Stewart-Williams reminds us at the beginning of his book, The Ape that Understood the Universe: How the Mind and Culture Evolve.
In order to reveal how “peculiar a creature we are,” Stewart-Williams offers an alien scientist’s perspective on modern human civilization, studying us as we would study animals in the wild. These aliens, while smarter and more knowledgeable than us in most domains, are “gender-neutral, asexual, asocial, amoral, areligious and amusical.” Presumably, they have also never encountered the inverse of these rather bland descriptors, and so the human expression of these traits is, well, alien to them. The resulting analysis is like something out of a Guardians of the Galaxy movie—funny in a fish-out-of-water, adorably innocent way. But, more importantly, Stewart-Williams succeeds in exposing the oddities in our behavior that do, in fact, require explanation.
The scientist’s report begins with a subtle thought-provoking justification for studying humans. He (I’ll stick with this pronoun for convenience) tells us that, on Earth,
Forests began disappearing, to be replaced with fields of ‘corn,’ and ‘rice,’ and ‘wheat.’ The ground started sprouting strange structures, now known as ‘cities,’ which spread across the planet’s surface like bacterial molds … Then, in the last century, the process went into overdrive. The Earth suddenly became a major emitter of radio waves. Weird metallic objects jumped into orbit … leading some [aliens] to suggest that the Earth was a growing sensory system, thereby becoming aware of itself and its surroundings. It was this possibility that first drew the attention of the Great Galactic Council.
Stewart-Williams challenges the notion that what is obvious to us is obvious in general. The aliens do not immediately ascertain that cities and other “weird metallic objects” were created by people. For all they know, the complex, inanimate objects might have emerged by some other process. When the alien scientist finally arrives on Earth to see for himself, he observes interactions between these complex entities and “meat creatures,” thereby confirming that “evolution by natural selection was taking place on Earth.”
However, the narrator continues,
it was unclear what role the meat creatures (or ‘humans’) played in the strange events we’d detected. One suggestion was that they were the sex organs of the cities or maybe of the metal machines—the means by which the cities and the machines reproduced themselves. Another suggestion was that the meat creatures were slaves of the corn, the rice, and the wheat. Perhaps, these plants had somehow tricked the humans into launching a genocidal culling spree on their main competitors—the trees…
Here, Stewart-Williams is challenging another notion that we take for granted, namely, that humans have agency—that we command our ideas and technologies, and not the other way around.
As the alien scientist continues to report on what he has seen on Earth, Stewart-Williams finds endless opportunities to conjure up funny descriptions of aspects of civilizations at which we wouldn’t usually bat an eyelid: “Humans … live at the bottom of the sky on slow-moving rafts called ‘land masses.’” The alien doesn’t hesitate to take a condescending view of our species: “humans hibernate once or twice a day, ultimately spending around a third of their brief lives in this plant-like state. No wonder it took them so long to establish their civilization, such as it is.”
Eventually, the alien encounters behaviors that baffle him, and that Stewart-Williams will spend subsequent chapters explaining:
Many miniature humans (or ‘children’) are terrified of the dark, even though most humans live in boxes that keep them safe from night-lurking dangers.
Humans show no natural fear of many things that genuinely do pose a threat. This includes … ‘junk food,’ ‘cigarettes’ … ‘condoms’ and ‘the pill.’
Sometimes they leak from their eyeballs if they spot images of non-relatives suffering or starving half-a-world away.
Humans just don’t shut up … They use the noises to transmit ideas … most of these ideas are entirely unrelated to matters of survival or reproduction. Often they’re designed simply to elicit the weird ‘ha-ha’ noises that humans regularly emit.
I’ve left out comments on religiosity, artistic impulses, intra-species brutality and romantic rituals. But you get the picture.
Stewart-Williams promises to answer all the alien scientist’s questions about human behavior and human culture, by employing two offshoots of evolutionary theory: evolutionary psychology and cultural evolutionary theory. Evolutionary psychology, the author explains, is the supposition that “human beings are animals, and that like all animals, we’re products of natural selection.” Cultural evolutionary theory is the idea that humans, and humans alone on Earth, have the capacity to develop a culture that accumulates through time and “evolves in its own right.”
Evolution and Its Explanatory Power
In Chapter 2, Stewart-Williams provides the reader with philosophical tools that will be familiar to those who have studied evolutionary theory. He explains natural selection and its importance (in tandem with variation in a biological population) in explaining why organisms appear so well-designed, so adapted to their environments: “The design in nature comes not from a designer but from the mindless accumulation of favorable accidents over vast periods of time.”
In an unexpected take on the clichéd question what is the purpose of life?, Stewart-Williams asks but what has natural selection designed us to do? As he works his way through the hypotheses that might provide an answer, Stewart-Williams provides the reader with a guide to conventional evolutionary thinking, introducing concepts such as trade-offs, sexual selection, kin selection, inclusive fitness, the gene’s eye view, group selection and, finally, the neo-Darwinian synthesis. He explains each idea and its role in evolutionary theory in a digestible chunk that the layperson can readily absorb. After rejecting many of these hypotheses, through careful argumentation, Stewart-Williams finally answers his own question: “Genes are selected to the extent that they propagate themselves in the gene pool … and human beings, along with all other organisms, are gene machines.”
After convincing the reader that evolutionary theory applies to bodily functions in both animals and humans alike, Stewart-Williams moves on to the human mind, seemingly aware of the greater resistance his ideas will face in this domain. He offers us another powerful philosophical tool here by distinguishing between proximate and ultimate explanations, taking the example of sex. The proximate explanation of this activity is that “people have sex because they enjoy it,” while the ultimate explanation, in evolutionary terms, is that “people have sex because sex results in the production of offspring.” Anticipating a common criticism that is levied at evolutionary psychology, Stewart-Williams exposes the error in the charge that “according to evolutionary psychologists, people have an innate motivation to pass on their genes, and … we’re all constantly scheming about how we might achieve this.” The author retorts that we “act as if we’re trying to propagate our genes, but without any strategizing on our part and without us having gene propagation as an actual, literal goal.”
Stewart-Williams then enters territory that has become a minefield in our culture—he seeks to explain sex differences using an evolutionary psychology framework: “when we understand what the mind is designed to do—namely to pass on the genes giving rise to it—various aspects of the mind and behavior suddenly make sense in an equally satisfying rush of insight.” He offers evolutionary explanations for such phenomena as men’s tendency to seek more sex partners than women, people’s propensity to care more for their own children than for those of others, etc.
To make a case for any scientific theory, you must compare it to its strongest rivals. In this case, the alternative explanation of human behavior is that it is all culturally enforced, and that therefore any patterns we observe can be changed, given sufficient social pressure. This perspective, the author tells us, is that of the standard social science model: “The next question is how we can choose between the evolutionary explanations and the traditional sociocultural ones.”
Stewart-Williams offers a three-pronged attack—a recurring strategy throughout the book—in order to argue that, for some behavior, an evolutionary explanation is superior to a sociocultural one. This applies if the behavior in question persists despite social pressure, transcends cultural boundaries and is found in other species. When all three factors are present, evidence points to an evolutionary hypothesis, not a sociocultural one.
Many of the puzzles that plague Stewart-Williams’ alien scientist can be understood through a concept known as evolutionary mismatch: the idea that a population’s present environment differs from the environment in which its ancestors evolved. The reason why people fear snakes but do not fear cigarettes is because our ancestors evolved to fear the former, but not the latter—even though cigarettes pose a far greater danger to most modern people than snakes do.
Stewart-Williams delves into detailed explanations of sex differences, beginning with a remark that I imagine must have rattled the author’s sociologist friends: “Everyone knows that men and women are different … except social scientists.” Stewart-Williams summarizes the typical responses to claims that sex differences have evolved: denial; the assertion that any observed differences are due to discrimination; and the assertion that any observed differences are due to socialization. He spends much of the chapter tackling these arguments by comparing their predictions against the evidence. He also explores parental investment theory, by considering a hypothetical species in which the sexes differ in the amount invested in creating offspring. After predicting what selective forces would act on each sex in such a species, Stewart-Williams applies the theory to humans. As he does so, he repeatedly pokes fun at our modern cultural preoccupations. After convincingly demonstrating that men and woman have different appetites for casual sex, Stewart-Williams writes, “and female porn stars are paid more than the males—a genuine gender pay gap.”
One salient example that Stewart-Williams uses to adjudicate between the nurture only explanation and the evolutionary explanation of sex differences is the difference in aggression between boys and girls as they age. Evidence suggests that the “sex difference in aggression suddenly swells at puberty, and is greater among adolescents and young adults than among any other group.” The nurture only brigade are committed to arguing that gender socialization suddenly changes “at exactly the same stage of life in every culture and in many … species.” The evolutionary view, on the other hand, accounts for this phenomenon without invoking any such awkward causal mechanisms.
In the bluntly titled section “Enemies of the Truth,” Stewart-Williams discusses the moral implications of the denial of sex differences and of the interventions that some are currently advocating. This section is a must-read for the layperson and scientist alike.
Mating, Altruism and Memetics
Chapters 4 and 5 apply evolutionary thinking to phenomena ranging from beauty standards, through mating preferences, to altruism. The author elucidates examples that will make many readers uncomfortable—but he respects his readers enough to treat us as mature thinkers. In this age of tiptoeing around the truth, I greatly appreciated this. In an arguably risky move, Stewart-Williams criticizes social psychologists for disregarding kin altruism. The reason for this, he argues, is that “many psychologists … have an empty space in their brains where their knowledge of evolution should be.” Stewart-Williams is in the business of truth telling, not the business of making friends.
The final chapter deals with human culture, discussing memes, which are units of culture in much the same way as genes are the fundamental units of biological evolution. The memetic theory of cultural evolution asserts that “like genes, memes are subject to natural selection, and that selection favors ‘selfish’ memes—memes that, through accident or design, are good at getting themselves replicated and keeping themselves in circulation in the culture.” Stewart-Williams offers the evolution of the teddy bear as a harmless example. Apparently, teddy bears weren’t always so cute. But, as time passed, they gradually became more baby-like, since those teddy bears which looked more like babies sold in greater numbers than their uglier counterparts. Eventually, the adorable product with which we’re all familiar became the norm. The businessmen who contributed to this evolution needn’t have been aware of the directionality of this trend. They were only responding to consumer demand. In a sense, the cultural evolution of the teddy bear was designed by no one in particular. Sound familiar?
Stewart-Williams explores various memetic hypotheses regarding cultural evolution, in a manner which parallels his exploration of biological evolution in Chapter 2. He provides the reader with yet another set of mental tools, including model-based bias, demographic swamping, memeplex, cultural group selection theory and universal Darwinism. He provides memetic explanations of music, language, religion and even the human mind. He flips the conventional view of cultural evolution on its head by presenting it through a meme’s eye view, arguing that we don’t have memes, memes have us. In typically playful fashion, he muses that, “the evolution of selfish memes over the course of human history may have turned us all into publicists for whatever memes we happen to have caught or contracted.”
In the last section, Stewart-Williams considers gene-meme coevolution. This involves the idea that the ability to generate culture was adaptive, meaning that those individuals with a greater capacity for employing tools and traditions yielded more offspring than others. Over many generations, individuals grew more and more capable of creating cultural artifacts, and so individuals that could employ ever more complex tools were further selected for. “In this way,” Stewart-Williams writes, “our clever brains and our clever cultures coevolved.” The author invokes this hypothesis as a possible explanation for the evolution of language and intelligence, among other phenomena.
Finally, Stewart-Williams includes two appendices, which provide answers to common challenges to both evolutionary psychology and the theory of memetics. I’d urge the reader to keep these “How to Win” manuals handy even after finishing the book.
The Ape that Understood the Universe is a thrilling review of our best explanations of human behavior at a time when such theories are under attack. No idea should be accepted without criticism, of course—so Stewart-Williams meets every challenge that detractors have employed in their attempts to refute these ideas. He clearly anticipates backlash—and does not let it silence him. The author’s playful tone will make it difficult for hostile antagonists to label him with the slur of the day, although that won’t prevent them from trying. But, for those who are open to having their politically correct preconceptions challenged, The Ape that Understood the Universe is a wonderful entry point into learning how the scientific method works—it doesn’t care what you believe, nor what you wish were true. The beauty of the truth is that it survives all criticism thrown its away, as Stewart-Williams demonstrates in 300+ pages of evidence, arguments and refutations.