INTRODUCTION to CHAPTER FOUR
This chapter is mainly on Lamarckism and has critical and constructive messages. We focus on the meaning of Lamarckism as “the inheritance of acquired characters”.
On the critical side, the chapter rebuts the idea that social evolution is Lamarckian rather than Darwinian. This is mistaken for a number of reasons. First, Darwinism (suitably defined) and Lamarckism are not mutually exclusive. In fact, Darwin believed in Lamarckian inheritance in the biological world. Subsequent biologists have thought otherwise, but that is beyond the point. Second, even if Lamarckian inheritance did occur (as on our imaginary Planet Lamarck) it would still require some process of selection to explain evolution in populations. Consequently, if Lamarckism were true it would require Darwinism. (This point was made previously by Richard Dawkins.)
Lamarckism raises a number of other questions and problems. As the late David Hull pointed out, it is important to be clear about the meaning of “inheritance” in the “inheritance of acquired characters”. Inheritance must be distinguished from contagion. Otherwise the transmission of fleas from one dog to another would be the “inheritance of acquired characters”. It is clearly not.
In contrast to contagion, inheritance means the copying of developmental instructions. It is not good enough for a Lamarckian to say that if we develop strong arm muscles then our children will have strong arms too. The Lamarckian must uphold that we have passed on the developmental capacity to develop strong arms through our genes, which carry these (new) developmental instructions.
Now here comes the clinch, which signals the constructive part of this chapter. Hereditable “developmental instructions” (with a bit more definitional stuff added), are REPLICATORS. Consequently, simply to make sense of Lamarckian inheritance (leaving aside whether it is true or not) we have to adopt something like the REPLICATOR-INTERACTOR distinction. Those that reject the replicator concept while saying that (social) evolution is Lamarckian (e.g. Richard Nelson and Peter Richerson) cannot have it both ways.
Finally, and also on the constructive side, we consider possible social replicators (above the level of genes), namely habits and routines. When we address these replicators and consider possible Lamarckian inheritance in social evolution, further problems arise. Something (very vaguely) like Lamarckism may exist in social evolution but calling it Lamarckian is highly misleading.
1. Are Darwinism and Lamarckism mutually exclusive?
2. What is the difference between inheritance and contagion?
3. Why does coherent Lamarckism require the replicator concept?
4. What are possible social replicators?