Genes, memes, and the replication of bad ideas

Memes are said to be quanta of cultural ideas, symbols and practices, in the same way that genes are the basic unit of heredity in living organisms. The concept was floated by Richard Dawkins in his first and hugely successful foray into popular science writing – The Selfish Gene – as a way of using evolutionary principles to explain the propagation of culture.

It was a useful if loose analogy, and at one time facilitated the debate surrounding human social development and modern culture. Memetics is not science, however, and I’m not sure Dawkins ever intended memes to be taken as seriously as DNA.

A generation after the eminent biologist first coined the term, the meme idea is still around, and psychologist Susan Blackmore appears to take memes very seriously indeed. So much so that she talks of evolution’s second replicator as having now been followed by digital information, the bits and bytes of which are driven by the same “fundamental design process”. The letting loose of of this “third replicator” will, says Blackmore, have consequences that are “unpredictable and possibly dangerous”. Exciting stuff, and a little scary with it, such is the art of futurology.

“The idea of memes as a cultural analogue of genes has been much maligned, and most biologists still reject it. Yet memetics has much to offer in explaining human nature.”

Blackmore refers to “meme theory”, yet as far as the majority of natural and social scientists is concerned there is not even a testable hypothesis, and it is disappointing to see a natural scientist of Blackmore’s calibre misuse language in this way. Blackmore is one of my favourite popular writers on psychology, and I’m particularly interested in her work on altered states of consciousness and the value of psychotropic drugs.

So what does Blackmore have to say about this third replicator? Actually very little, and the latest article consists mostly of a defence of memetics…

“According to meme theory, humans are radically different from all other species because we alone are meme machines. Human intelligence is not just a bit more or a bit better than other kinds of intelligence, it is something completely different, based on a new evolutionary process and a new kind of information.”

Given recent advances in experimental psychology and ethology, anyone who continues to hinge their thinking on the uniqueness of human intelligence is on very dodgy ground. The more we learn about human and non-human animal behaviour, the less discontinuous is the divide between them.

Blackmore on the proliferation of memes…

“Once memes were proliferating, individuals benefited from copying the latest and most successful ones, and then passed on any genes that helped them do so. This “memetic drive” forced their brains to get bigger and bigger, and to become adept at copying the most successful memes, eventually leading to language, art, music, ritual and religion – the successful designs of human culture.”

The biggest weakness in the gene analogy is the propagation mechanism. There are crucial differences between biological and cultural evolution. For one, human beings acquire culture in the form of values, ideas and actions throughout their lives. With genes, however, the situation is not the same, as explained by Stockholm University ethologist Magnus Enquist:

“In connection with fertilization, all genes are transferred to the new individual at one and the same time. In contrast, the individual acquires culture successively and throughout life, which can lead to dramatic consequences and create widely divergent conditions for various individuals in a way that biological evolution does not.”

An individualʼs opportunities to actively choose among different cultural variants will greatly influence his or her development. As Enquist and his colleagues Pontus Strimling and Kimmo Eriksson show with the aid of mathematical models, earlier choices form a foundation for those to come, and differences between the cultural evolution of individuals can be tied to how often they are exposed to cultural influences. The frequency of exposure shows that the fewer occasions for exposure an individual encounters, the weaker is their social-cultural evolution.

“In such cases the capacity for dissemination is what determines evolution, in the same was as with biological evolution.”

Enquist’s models show that it makes no difference whether culture is passed on by parents, peers or the collective, and this is the most important difference between biological and cultural evolution. There is no simple principle which can predict cultural evolution in the same way that the fitness of an organism influences biological evolution. However, it would seem that one can employ a simple variable to predict the prevailing cultural variant when the number of learning opportunities is great.

A grand unified theory of cultural evolution may in principle be possible, but it will necessarily have its own peculiar characteristics, and not be tied to biological evolutionary thinking. It’s about time that we dropped the meme idea from social discourse and moved on. Science already has.

Further reading

Susan Blackmore, “Evolution’s third replicator: Genes, memes, and now what?”, New Scientist 31 July 2009

Strimling et al., “Repeated learning makes cultural evolution unique”, PNAS (2009)