Biological and Cultural Proper Functions in Comparative Perspective 39
in the past and relying on continuing usefulness to pick out proper functions in the
present.
David Buller (1998) weakens this reliance on natural selection still more. He gives
three reasons why selection may never have operated in the case of some erstwhile
proper functional traits: 1) genetic drift rather than natural selection may have caused
their proliferation, 2) there may never have been signifi cant variations, and 3) in addition
to assigning proper functions to whole traits we also want to assign them to the
component parts of those traits, but a given component might be invariant in all variations
of a trait, and thus not under selection in its own right. Reasons (2) and (3) are clearly
the same problem—lack of variation. This is a problem already identifi ed by Schwartz.
And genetic drift is of course a favorite example of those who wish to point out that
evolution at times proceeds by means other than natural selection. Buller’s criticism is
more radical than Schwartz’s because Schwartz only identifi es cases where natural
selection is no longer operating, whereas Buller identifi es cases where it never
operated but where there is a performance contributing to survival and reproductive
effectiveness that seems otherwise to warrant the proper function label. To solve this
problem, Buller proposes a weak etiological theory. On this view a trait has a specifi c
proper function if a) the performance associated with that function contributed to the
fi tness of the ancestors of present organisms with the trait, and if b) the trait is hereditary.
“Strong” etiological theories such as Millikan’s appeal exclusively to natural selection to
pick out proper functions. Buller’s “weak” theory, in contrast, appeals to fi tness of inher-
ited traits.
Let us now pause to ask whether there is an analogous process of cultural selection, and
whether it is subject to the diffi culties Schwartz and Buller have identifi ed. To be analo-
gous, cultural selection must involve competing variants of items of material culture, one
of which proliferates while the others disappear. This phenomenon occurs in at least two
contexts. First, design often involves the building and testing of a number of prototypes,
one of which is then selected for reproduction while the others are consigned to the dustbin.
Second, the economic processes of marketing and distribution often involve the appear-
ance of a number of competing variants of a type of item, one of which proliferates while
the others disappear. For example, quill pens disappeared with the advent of fountain pens;
and Microsoft Word has arguably outcompeted other word processing systems, which are
rapidly disappearing. So selection among alternative variants is a feature of material
culture just as it is of biology; and it may be hypothesized to pick out proper functional
performances of artifacts just as natural selection is hypothesized to pick out proper func-
tional performances of biological traits.
But does this hypothesis run afoul of cultural phenomena analogous to those identifi ed
by Schwartz and Buller in the biological realm? Both of them pointed to lack of variation
as a major problem. And examples of this in material culture are not far to seek. Simple,
everyday implements like baskets, spoons, and brooms often remain virtually unchanged