My previous column explained how “evolutionary psychologists” claim to show that all basic aspects of an organism are best understood as the product of its genes.
In other words, instructions for building organisms reside in the genes, and genes are the vehicles by which these instructions are transmitted from one generation to the next.
Central to this argument is the thesis of ancient provenance — the idea that recent history is too brief a period to have produced significant changes to humans’ genes.
The problems that the brain evolved to solve are, they argue, those of past environments. To explain why we have the genes we do, the evolutionary psychologists say, we must look at the long period during which humans developed their distinctive genetic endowments that distinguish us from our nearest relatives.
This period is generally identified as the Pleistocene, or Late Stone Age, the epoch spanning 1.8 million to 10,000 years ago.
This leads evolutionary psychologists to the idea that reflections on the conditions that human ancestors encountered in the Pleistocene hold the key to identifying the behaviour of contemporary humans. But there are problems with this idea.
First, there still remains much to be known about aspects of the theory of human origins.
More importantly, it is simply not the case that there has not been significant genetic evolution since the end of the Pleistocene.
Recent evidence suggests that two human genes involved in the evolution of brain size have continued to evolve in humans within the past 10,000 years. Of course, the advantage provided by such change is unlikely to have been dramatic, but the fact remains that this could have modified human behaviour.
And of course, the environments inhabited by modern humans have changed in important ways since the Pleistocene. Where Pleistocene humans lived in groups of 50 to 300, post-agricultural humans have lived in increasingly larger groups, which affect the different challenges that humans face.
Even if our ancestors had evolved “mental modules” that solved the problems they faced in the environments of the Pleistocene, such modules would be useless in the world of the wage-labourer, since the tasks leading to, for example, the acquisition of food have changed so radically.
And finally, it is a mistake to view human behaviour as encoded in the genes.
This remains something of a dogma of evolutionary thought, and is also associated with the gene-centred perspective on evolution made popular by Richard Dawkins. In my view, it is entirely mistaken and is perhaps the greatest obstacle to the progress of thought about evolution.
But this need not be the case. There is a more radical movement that is rapidly gaining adherents, myself included.
This movement sees evolution as a continuous process and disputes whether it is possible to analyse it successfully by separating out a privileged set of objects — genes, for example — involved in a certain stage of the process.
The most influential version of this perspective is developmental systems theory (DST). This theory provides a powerful critique of the gene-centredness of supporters of evolutionary psychology.
The two most important aspects of DST are that it does not privilege the gene, and it breaks down the divorce between evolution and development.
For DST, the smallest unit in terms of which evolutionary processes can properly be understood is the full developmental cycle. This runs from a given stage in the life cycle through all the steps needed to reproduce that stage in the next generation.
In this view, genes are merely one developmental resource among others that are required in order to complete the various stages of the life cycle.
Theories that centre on the gene give a specific answer to the famous question about chicken and eggs — the egg came first. DST gives the more plausible answer — neither or both.
Everything necessary for the reproduction of the developmental cycle is equally necessary for understanding the evolutionary trajectory of the organism.
Darwin and his followers have provided us with fundamental insights into the nature of the world we live in and of our place within it.
In this, we have taken a step closer towards a naturalistic world-view that is able to dispense with spirits, ghosts and gods.