The Meme Machine

34 THE MEME MACHINE
The Stanford geneticists, Luigi Cavalli-Sforza and Marcus Feldman (1981),
developed a detailed model of cultural transmission based on the ‘cultural trait’
as the unit. Cultural traits are learned by imprinting, conditioning, observation,
imitation or direct teaching (note that this is a broader range than for memes
which, by definition, have to be passed on by imitation and cannot be acquired
by imprinting or conditioning). They clearly distinguish cultural selection from
Darwinian or natural selection and they use the concept of ‘cultural fitness’ –
that is, the fitness for survival of a cultural trait itself – a concept that is useful in
memetics. They also introduced the distinction between vertical transmission –
such as from parent to child – and horizontal transmission – such as from child
to child or adult to unrelated adult. We shall see later how important this is for
understanding life in an age of predominantly horizontal transmission.
Cavalli-Sforza and Feldman listed different mechanisms of cultural
transmission and provided mathematical models of particular cases, including
maladaptive ones. A seriously maladaptive example is the practice of
cannibalism in the funeral rites of a New Guinea highland tribe called the Foré.
As part of complex rituals honouring their dead the Foré ate parts of the human
bodies. In fact, they preferred eating pork to human flesh and so the men tended
to get more of this prized food, leaving the women and children to more
cannibalism (Durham 1991). This practice led directly to an epidemic of the
degenerative disease known as kuru, which killed about 2500 Foré people,
mostly women and children. Cavalli-Sforza and Feldman demonstrated
mathematically that a maladaptive trait like this could eliminate up to 50 per
cent of its carriers and still spread through a population.
However, despite contributing so much to our understanding of cultural
transmission and the spread of maladaptive practices, Cavalli-Sforza and
Feldman still see ‘cultural activity as an extension of Darwinian fitness’ (1981,
p. 362), and this is what distinguishes their theory from memetics. As Dennett
(1997) puts it, they do not ask the all-important Cui bono? question. Or, if they
do, they simply assume that the answer must be genes, and do not consider the
possibility that ‘it is the cultural items themselves that benefit from the
adaptations they exhibit’ (Dennett 1997, p. 7). For Cavalli-Sforza and Feldman,
cultural adaptation means the use of skills, beliefs, and so on, to the ultimate
benefit of genes – and the term ‘maladaptive’ means maladaptive to the genes.
Even if only in the long run, they say, ‘The mechanism of natural selection
retains ultimate control’ (Cavalli-Sforza and Feldman 1981, p. 364). In other
words they too believe in the leash.