On Deep History and the Brain (review)

World historians are of two kinds—the professionals and the interlopers. Smail, in real life a talented historian of medieval Europe, is emphatically an interloper, but one with an unusually grand vision of what the study of the human past should be. In essence, his vigorous and spirited book is a plea for two things, each of them represented in his title.

The first is “deep history.” The depth is chronological: Smail is making a case for a history of our species that reaches far back into the Palaeolithic. He does not simply mean that historians ought to pay some attention to what prehistorians, archaeologists, and geneticists have to say about the Paleolithic background to history; such an approach would do no more than ask historians to cross a disciplinary boundary. His proposal is much more ambitious: He sees the Palaeolithic not as the background to history but rather as an integral part of it; in other words, he seeks to remove a disciplinary boundary. To this end, he launches a polemic against the normal restriction of “history,” understood as a label for what historians study, to the last few thousand years. To make his colleagues feel bad about this restricted usage, he tells them that what they are really doing is holding fast to the traditional Christian chronology, according to which the world was created around 4004 b.c. But he also turns his guns on what is surely the real reason for sticking to shallow history—namely, that it makes a big difference whether or not the past can be studied on the basis of human memory, typically as represented by written sources.

If there is a major problem with Smail’s argument, it is that he has not confronted the practical implications of his program. Would he really have people trained in the discipline of history excavating Palaeolithic sites and sequencing Palaeolithic dna? And would he have prehistorians, archaeologists, and geneticists change their professional identity and move into history departments, pushing for academic cleansing to free up the necessary lab space? Such a program seems more like a recipe for indiscipline than for interdisciplinarity. But if this is not his intention, it is unclear just what he is proposing—unless, perhaps, he is trying to have it both ways, combining the modest substance of crossing a boundary with the rhetorical panache of abolishing one.

Smail’s other plea concerns the brain: He would like historians to give an ear to neuroscience. Indeed, one of his chapters bears the title “The New Neurohistory” (he does not divulge what the old neurohistory was). It is certainly in the interests of historians that some of their number should keep a watch on what scientists are doing. Geneticists, for example, do not simply confirm that our ancestors had genes; they provide solutions to historical problems that cannot be resolved from written sources. But can neuroscience, at least in its present state, match the contribution of genetics? It can reveal the physical underpinnings of our thoughts and feelings, and by implication those of our ancestors; but with one possible exception (154), it is not clear from Smail’s account that it can provide new historical information in the way that genetics can and does.

Within the discussion of neuroscience, the last substantive chapter narrows its focus to the psychotropic—activities and substances that humans use to effect changes of mood in themselves and others. This is the chapter most likely to have a positive effect on the mood of readers. One of its high points is an account of the phenomenal growth of the psychotropic techniques at the disposal of eighteenth-century Europeans, from erotica to tea. Another is its analysis of the use of random violence to achieve social dominance by medieval castellans, male chimpanzees, and—lest the comparison seem unduly sexist—some female baboons.

On Deep History and the Brain falls somewhere between an overlong manifesto and an overshort book. Those passages in...