Wednesday 1 June 2011

Why are memes adaptive?

We can be pretty sure that memes were adaptive among our ancestors since we have meme-spreading adaptations - our incessant babbling, our ultrasociality and the huge meme libraries we carry around everywhere on our shoulders.

It seems likely that memes are adaptive today - at least up to a point - since meme-free humans are like primitive cave men, and most such creatures would not do very well in the modern world.

However, neither of these sets of observations really explains the reasons why memes are adaptive.

Part of the explanation probably seems obvious. Memes allow individuals to:

  • Reduce the costly errors associated with trial and error learning;
  • Acquire useful ideas much more quickly than trial and error would permit;
  • Acquire better quality ideas than they would have been likely to produce themselves;
Boyd and Richerson have looked into the issue of why culture is adaptive - presenting their results in Richerson and Boyd (1995) and their 2005 book on the topic, Not by Genes Alone.

They give more-or-less the above analysis. However, in Not by Genes Alone (2005, p.127) they then go on to give what they themselves describe as a just-so story about the circumstances under which culture is adaptive.

The title of their section on the topic is: "Culture is adaptive because it provides information about variable environments". It argues that memes are adaptive because they allow humans to adapt better to local conditions. They give plenty of examples over four pages. It is certainly true that culture helps humans to adapt to local environments. However, the whole theme is really a misleading and inaccurate one.

The reason memes are adaptive is because they let you obtain good quality ideas quickly, and at low cost. Some of those ideas are no-doubt contain information about how to adapt to local environments. However, others are more universal. For example, fire, love songs, levers and hammers are useful in a wide range of conditions and environments.

Why transmit these ideas culturally, rather than wiring them into the genome, then? The answer is essentially because the genome is full, and can't really accomodate all the universal cultural knowledge. Even if evoultion could somehow find a way to wire a fire-starting instinct into the genome, the results would not be much better than transmitting the knowledge by cultural means. So, this is a challenging task for evolution with a pretty minimal payoff.

So, my council is to forget about the benefit of memes being enhancing the ability to adapt to local environments. The bottom line is that memes benefit people by allowing them to obtain lots of good quality ideas quickly, and at low personal cost.

References

  • Richerson, P. J. and Boyd, R. (1995) Why Does Culture Increase Human Adaptability? Ethology and Sociobiology. 16: 125–143.
  • Richerson, P. J. and Boyd, R. (2005) Not by Genes Alone: How Culture Transformed Human Evolution. University of Chicago Press: Chicago, IL.

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