by Daniel Gilbert:

[P]sychologists . . . take a vow, promising that at some point in their professional lives they will publish a book, a chapter, or at least an article that contains this sentence: "The human being is the only animal that . . ." . . . Most of us wait until relatively late in our careers to fulfill this solemn obligation because we know that successive generations of psychologists will . . . remember us mainly for how we finished The Sentence.

[T]hose psychologists who finished The Sentence with "can use language" were particularly well remembered when chimpanzees were taught to communicate with hand signs. And when researchers discovered that chimps in the wild use sticks to extract tasty termites from their mounds (and to bash one another over the head now and then), the world suddenly remembered . . . every psychologist who had ever finished The Sentence with "uses tools." So it is for good reason that most psychologists put off completing The Sentence for as long as they can, hoping that if they wait long enough, they just might die in time to avoid being publicly humiliated by a monkey.

I have never before written The Sentence, but I'd like to do so now, with you as my witness. The human being is the only animal that thinks about the future. . . . I do recognize that nonhuman animals often act as though they have the capacity to think about the future. But as bald men with cheap hairpieces always seem to forget, acting as though you have something and actually having it are not the same thing, and anyone who looks closely can tell the difference.

[E]very autumn the squirrels in my yard . . . act as though they know that they will be unable to eat later unless they bury some food now. . . . [T]hey have regular squirrel brains that run food-burying programs when the amount of sunlight that enters their regular squirrel eyes decreases by a critical amount. Shortened days trigger burying behavior with no intervening contemplation of tomorrow, and the squirrel that stashes a nut in my yard "knows" about the future in approximately the same way that a falling rock "knows" about the law of gravity—which is to say, not really.

Until a chimp weeps at the thought of growing old alone, or smiles as it contemplates its summer vacation, or turns down a Fudgsicle because it already looks too fat in shorts, I will stand by my version of The Sentence. We think about the future in a way that no other animal can, does, or ever has, and this simple, ubiquitous, ordinary act is a defining feature of our humanity.

(Paragraph breaks added.) The sentence about bald men with cheap hairpieces is not only funny but also connects with long-standing debates about modeling human behavior in economics. For a longer excerpt, see here.