Psychology: Essential Thinkers, Classic Theories, and How They Inform Your World - Andrea Bonior 2016

Charles Darwin
Biological Psychology
The Canon

BORN 1809, Kent, England

DIED 1882, Shropshire, England

Educated at the University of Edinburgh and Cambridge University

BIG IDEA

Charles Darwin’s ideas fundamentally and permanently altered the course of psychology. No doubt you’ve heard of Darwin, the father of evolutionary theory, if only because of the Darwin Awards, a tongue-in-cheek recognition of people who improve the human gene pool by accidentally sterilizing or killing themselves through their own unintelligent actions. Darwin’s name is invoked in this connection because of its association with the notion of the survival of the fittest.

Darwin’s seminal work, On the Origin of Species, was published in 1859, and it laid out his groundbreaking ideas on natural selection and sexual selection. (Interestingly enough, Darwin’s insights preceded this book’s publication by many years, a fact that has led some to believe that he was nervous about the possibility that his work would have a far-reaching negative impact on society.) The term natural selection points to the idea that nature, over time, will eliminate maladaptive traits that are not useful to a species, since specimens that have such traits die off more quickly than their counterparts that lack those traits. The term sexual selection points to a more active and intentional pursuit of various adaptive traits as one aspect of mating behavior. (In other words, Darwin believed that organisms are capable of swiping right, the way human beings do on apps like Tinder.) As for why sexual selection works, it’s because potential mates who possess the adaptive traits are deemed more desirable: they’re likely to survive longer and can propagate stronger members of the species because their adaptive traits will live on in their descendants. This process takes place at the level of the individual organism, of course, but it also has macro-level effects on the whole species.

Charles Darwin, following this logic, also surmised that many different species, including humans and apes, probably had a common ancestor. In other words, evolutionary theory says that just as you and your cousin share a grandmother, humans and apes—and, if we go way back, all other species—originally emerged from the same organism. This was a controversial idea at the time, and many contemporary caricatures depicted Darwin himself as an ape. Despite the backlash, however, Darwin launched an irreversible process, and his theory of evolution gained ground. Eventually, more and more people came to believe that human beings have not always looked the way we do today, and that, just like other animals, we descended from earlier creatures.

Most people understand this concept at the level of anatomy—human beings and cave dwellers evolved from the same ancestors, and the physical traits that made the cave dwellers better able to ward off predators, live healthier lives, and adapt to their environment survived and now live on in human bloodlines. But many people don’t consider that Darwin’s theories can also be applied quite readily to psychology. In fact, the same human characteristics that we tend to think of as differentiating us from other animals—the ways we think, feel, behave, and react—all began as evolutionary adaptations, and they’ve been bred into us over thousands of years. Just as we no longer have tails, Darwin thought, we no longer think in ways that were already not working to our advantage thousands and thousands of years ago.

The longer Darwin observed animals, the more he noticed connections between human and animal emotions and behavior. As a result, he began to view the difference between humans and other animals as one of degree, not of kind. A later work by Darwin, The Expression of the Emotions in Man and Animals, includes remarkable illustrations of this idea, not only in words but also in drawings by various artists and in early photographs. For example, chimpanzees are seen to sulk and pout in ways that make them look similar to humans. When a cat faces a predator, the cat’s face widens in fear, not unlike what happens when a human being is frightened. When a macaque receives a pleasant caress, its face shows unmistakable happiness.

Darwin also recognized that human emotions remain very similar across different cultures. He identified many emotions—love, joy, devotion, anxiety, despair, grief—that appear to have universal expressions, and he theorized that such expressions serve to communicate our inner feelings to other members of our species.

THEN WHAT?

Darwin’s ideas changed the direction of psychological thought in several ways. Later theorists became more interested in individual differences among people, and in how those differences might result from genetic factors as well as from long histories of varied adaptations. (This interest also has a darker side, involving theories of racial superiority and inferiority.) Darwin’s work also opened up lines of research into intelligence and personality. Ethological psychology—another branch of psychology borrowed closely from Darwin’s theories—was most famously promulgated by Konrad Lorenz, who looked at animals in their natural environments and observed such genetically ingrained behaviors as imprinting. (There exists some rather amusing footage of geese obsessively following Lorenz. The geese clearly believe that Lorenz is their mother, since his image became imprinted on them early in their lives, thanks to a gosling’s survival-oriented genetic predisposition to attach to the first animal it lay eyes on during a critical early period after birth.)

KEY EXPERIMENT Charles Darwin made a series of observations during a nearly five-year journey aboard the HMS Beagle to survey various parts of South America. That journey didn’t constitute an experiment per se, but Darwin’s observations served as a major catalyst for the development of his theories. (Ironically, the ship’s captain, Robert FitzRoy, originally hoped the voyage would substantiate the book of Genesis and give scientific discoveries a more biblical slant, but that goal went extinct, so to speak, when Darwin began observing animals in the Galápagos Islands off the coast of Ecuador.) Darwin was struck by the vast number of species within a single genus, most particularly in the case of finches and the species of tortoise for which the islands were later named. Even more remarkable than the number of different species within a genus was the fact that each species appeared to have developed its own characteristics as a specific adaptation to its own environment (for example, different finch species had different types of beaks that gave them access to different local food sources). It was already understood that human animal breeders can select for various characteristics, as breeders do with dogs, for instance. But Darwin’s observations in the Galápagos Islands led him to conclude that nature, too, could select for particular traits, and that the traits most likely to be targeted by the process of natural selection were those most likely to be linked to an animal’s survival.

WHAT ABOUT ME?

Think of something that really, really scares you. What came to mind? Was it spiders? Heights? Snakes? Lightning? Rats? If you thought of what is most likely to kill you in this day and age, you probably thought of cars, pills, guns, or maybe electrical outlets. But chances are that you, like almost everyone else, continue to feel most threatened by things that in no way represent the greatest dangers you actually encounter on a daily basis. What accounts for the fact that few people are walking around with a fear of electrical outlets, even though the modern psyche retains its fear of things like heights, snakes, storms, spiders, and open water? The answer is that fear of such things was very rational for our cave-dwelling ancestors. Those fears helped keep them alive. And our ancestors’ fears also kept humans alive as a species, since our ancestors had a biological interest in keeping their genes going.

Speaking of which, what are the traits that you look for in a mate? There’s a lot of variation in this area, of course, since different cultures have different standards of beauty. In addition, not all of us, whether we’re gay, straight, or in between, are interested in mating solely for the sake of reproduction. Nevertheless, the traits that most people find sexually attractive do seem to reflect the desire to maximize human offspring’s chances of survival.

A woman looking for a longer-term mate may tend to be attracted to a provider type—someone whose stability, trustworthiness, and even financial resources hint at the ability to provide for offspring. A man seeking a mother for his offspring may tend to look for traits like a nurturing personality, warmth, and kindness. And when it comes to purely physical traits, the profile pictures on any online dating site will quickly confirm that height and strength are thought to be attractive in a man, and that a curvy, feminine figure is seen as attractive in a woman. Both sets of traits signal youth and fertility, and they seem to have seeped into human sexual desire, whether someone is hoping to have a baby or simply score a hookup. Across cultures, people of both sexes also tend to seek out traits that signal a basic level of genetic fitness, such as symmetrical facial features and a complexion free of apparent illness or infection. Interesting research has also suggested that a heterosexual woman’s assessment of a man’s attractiveness may vary according to where she is in her menstrual cycle, and that she may seek out even more masculine and symmetrical features while she is ovulating.

In short, much of the behavior that seems to come to us most naturally has not always been inherently human behavior. Instead, it reflects human adaptations to the environment over time. Those adaptations motivated our ancestors, as they also motivate us, to keep our genetic lines going. What feels to us like acting naturally is behavior that evolved to help keep us safe and make us smarter, stronger, and healthier.