Is it possible that most historical events, from the most innocuous yawn to the fiercest war, have been about little more than relieving us of boredom by slightly jarring our brain chemistry? In a nutshell, that seems to be the thrust of Alexander Star’s review of Daniel Lord Smail’s book On Deep History and the Brain. The review was published in the March 16 edition of the New York Times. Alexander places Smail, a Harvard medievalist, in league with “nonhistorians like Jared Diamond and Tim Flannery who seek to trace the long arc of the species and write macrohistory in a scientific key.”

According to Smail, humans have invented “a dizzying array of practices that stimulate the production and circulation of our own chemical messengers.” These are said to include not just obvious stimulants such as coffee and tobacco, but virtually any emotionally-laden practice, from religious rites to romance novels. Alexander opens the review with the striking claim that this urge gives our brain a periodic charge is not limited to humans, but that even the spontaneously snort of a horse is an attempt to elicit “an automatic ‘startle response’ — flooding its brain with chemicals, delivering a jolt of excitement and relieving, at least for a moment, the monotony of a long day in an empty field.”

The comparison to animals is no accident, for what underlies Smail’s startling conclusions [is his book an example of his theory?] is a natural selectionist view of history. But the selection at issue is not entirely biological, but behavioral as well. Alexander writes:

The imperfect copying of past behavior and small, often unconscious preferences can push a society in a new direction, even without anyone aiming toward a particular goal. It’s possible, for instance, that early men decided to make sharper spear points with the intent of drawing more blood from their prey; Smail would rather suppose that these spear points were created by accident, and then spread because the hunters who used them proved to be better hunters, even if they didn’t know why. Cultural evolution can be rapid and it can help human beings adapt to their environment, but it needn’t be intended or progressive.

The relation of this claim to the theory of “organic selection,” first proposed by developmental psychologist James Mark Baldwin in 1896 (now better known as the “Baldwin Effect”) is apparent to the historian of psychology.

Alexander continues:

Ever since the invention of agriculture, Smail claims, we have seen “an ever greater concentration of mood-altering mechanisms.” Some of these mechanisms Smail refers to as “teletropic”: they work primarily to affect the moods of others, stimulating a wash of neurochemicals at a distance. A baby cries and arouses its mother’s instinct to care; a priest intones a Mass and relieves parishioners of stress hormones. The modern era, however, belongs to what Smail calls “autotropic” devices, devices that alter our own moods. In modern Europe, coffee from the Arabian peninsula became a stimulant to “mind, body, conversation and creativity” for the rich and the mercantile. The cultivation of sugar on Caribbean slave plantations made cheap rum freely available, further inebriating the working classes. Individuals became ever more expert at changing their own chemistry, sometimes just for the pleasure of modulating one set of sensations into another. But ingesting substances was only the beginning. The same era saw the rise of novels and erotica, shopping and salons. Books are also autotropic devices, regulating attention and mood; indeed, in the 18th century, their impact was often likened to a fever, jeopardizing readers’ purchase on reality and their physical strength. In the age of Enlightenment, man overthrew kings and subjected himself to mild and intermittently pleasurable addictions.