248 Tim Lewens
the constraining or facilitating properties of commonly found construction materials, but
it may also mean looking to characteristic patterns of thought among innovators. The
“heuristics and biases” literature (e.g., Gilovich, Griffi n, and Kahneman 2002; Kahneman,
Slovic, and Tversky 1982), when used to shed light on the psychological dispositions that
affect what sorts of artifacts are considered for use and development, would constitute a
typological explanation of this second sort.
Just as evolutionary developmental biologists have argued that standard models of
evolutionary change ignore the relevance of the concrete details of organisms and instead
focus exclusively on selection pressures for the explanation of organic change over time,
so an EvoDevo school in technology change might fi nd fault with standard evolutionary
models for ignoring the relevance of the concrete details of artifact production and focus-
ing instead on selection pressures exerted by users (or other selectors) in explaining tech-
nological evolution. Models that marry heuristics and biases with market-based selection
mechanisms would be the technical analogues of the biased embryos program in evolution-
ary developmental biology. So-called evolutionary economics seeks to broker just such a
marriage (Nelson and Winter 1982; see also MacKenzie 1996).
14.5 Boyd and Richerson’s Population Thinking
Mayr uses “population thinking” as a label for many different, albeit related, forms of
thinking. The core sense that I outline in section 14.3 is not the only form of population
thinking praised by Mayr. If Boyd and Richerson feel that population thinking is the key
to an informative evolutionary theory of cultural change, then perhaps what they mean by
“population thinking” corresponds to one of these alternative forms.
One of the curious things about population thinking is that its advocates often seem
undecided on whether it is primarily about populations at all. Mayr says, “Averages are
mere statistical abstractions; only the individuals of which the populations are composed
have reality.. .” (Mayr 1976: 29). Of course this does not commit Mayr to denying that
populations exist, but it credits only individuals with “reality” and hints at least at a skepti-
cism regarding the explanatory importance of population-level properties (such as aver-
ages). In an important article, Elliott Sober takes issue with Mayr regarding this point.
Sober suggests that the true importance of population thinking lies in crediting popula-
tion-level properties with explanatory effi cacy (Sober 1980). It appears that for Mayr,
however, we should explain population-level phenomena in terms of the properties of
individual organisms and their interactions.
Boyd and Richerson’s population thinking expresses their belief that we should under-
stand culture in terms of the combined effects of the interactions of the individuals that
make up cultural groups. This explains, once again, why their “population thinking”
stresses the importance of keeping track of individuals and their properties: