“We may be through with the past, but the past ain’t through with us.”

The quote is from the 1999 film Magnolia, starring Tom Cruise, Julianne Moore, and Philip Seymour Hoffman. The line is an almost oracular pronouncement about the troubled pasts of the movie’s protagonists, whose lives are now momentously intertwined in the story’s present moment. But it is even more apt as a mantra or slogan for the evolutionary view of human nature, which looks at the deep, “geological” past of our emotions and instincts. Here’s why.

Applied to individual lives and histories, the idea of a past that “ain’t through with us yet” is a cornerstone of many areas of thought—history, philosophy, Freudian psychoanalysis, folk psychology, fictive storytelling, biblical exegesis, and so forth. But in most of these instances, the intended explanation remains at the level of what evolutionists call “proximate” causation. These are histories near by in space and time: individual, familial, and cultural milieus that tell us how a person or group of people behave, or in a local sense, how they got to be a certain way.

“Ultimate” causation and explanation pertain to traits that helped a species survive and reproduce throughout its phylogeny. Looking through the lens of natural selection helps us understand why a certain animal behaves one way and not another way, why a given trait was selected over another one. Here’s a well-known example: male songbirds sing in spring because the increase in sunlight produces a certain hormone. This is just a proximate explanation, because it doesn’t tell us why the trait exists in the first place. An ultimate explanation must explain why singing (as opposed to making some other noise, call, or scent) in springtime (as opposed to any other season) improved the songbird’s chances of reproductive success, thereby conserving the trait and increasing the frequency of “singers” in the gene pool.

OK. That’s Evolution 101, but now comes the hard part. It’s easier (for some) to accept the evolutionary lens when looking at the shape and function of body parts, organs, and such, but we resist looking through that lens at the things that make us who we are: our personalities, our life choices, whom we find attractive, the music we listen to and the stories we tell, and the value systems that give us meaning and purpose. We feel that such a view is “reductive,” cold, mechanistic, superficial, or even pernicious. To borrow a term from theology, there seems to be a kind of Bilderverbot (the ban on representing the divine) about representing the human mind as a product of evolution. On a side note, it’s worth mentioning that this resistance is probably an evolved instinct as well—part of what Paul Bloom has called an innate instinct to be “dualists” about the mind.

There are many criticisms of the evolutionary view of human nature, and most of these have been the subject of ongoing debate and commentary. In this series of posts, of which this is the first installment, I will address one of the most pervasive objections, particularly among secular humanists and even some scientists: the notion that we’re telling “just-so stories” about human nature. The term is a reference to Rudyard Kipling’s 1902 book Just So Stories for Little Children, which includes tales such as “How the Camel Got His Hump” and “How the Leopard Got His Spots.” It is shorthand for the ad hoc fallacy, that not-so-scientific propensity for inventing fanciful explanations to fit facts already in evidence.
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As a kind of primer on the topic, I encourage interested readers to check out David Barash’s article, in The Chronicle of Higher Education, entitled “How the Scientist Got His Ideas."

At face value, this may seem like a simple exercise in distinguishing fact from fiction. After all, it should be a matter of course to distinguish between a fantastic tale of origins and an account that’s consistent with what we know about the biology of life on this planet. But of course, it’s never that simple. It doesn’t help that some fanciful ideas about origins, masquerading as science, have been used to harm people—and that is a perpetual danger.

One important reason why the boundary between fact and fiction gets blurred is the ubiquity of human meaning systems. In what is perhaps the most fascinating turn in recent evolutionary thought, researchers have begun to investigate just how and why humans evolved to believe, make value judgments, and commit to deep convictions based on scanty evidence. Even as they obstruct our view of the mechanistic world, certain kinds of “adaptive fictions” may serve an essential purpose, and one that has little to do with empirical fact.

As a literary theorist and historian of ideas, here’s something I know about: how we construct non-mechanistic systems of meaning—and then cling to them for dear life. Maybe, just maybe, our meaning systems are the most powerful and moving example of the way in which our deep evolutionary past “ain’t through with us” yet!