What would EPC select for?
Picture a population of coastal birds, like seagulls. To make a living, they have to obtain their food from the sea. They hunt for small fish and crabs.
Fishing in the area is calorifically lucrative for a time, but it can only sustain so many birds. The bird population grows so that its calorie consumption matches the total amount of calories that can be extracted from the local environment by fishing (like a seagull, at any rate). This theoretical maximal population is called the carrying capacity of the environment.
At this point, making a living by fishing has become fairly difficult. The population can no longer grow, so the average number of surviving adult offspring per bird is two. Female seagulls lay (and male seagulls sire) a lot more than two eggs during their lifetime, but the rigors of early life are fatal to most chicks. In this example, they mostly die because there is no longer enough fish to go around. Adult birds can perhaps fast a few days when they cannot get fish, but such lean days are often fatal to baby birds.
In reality, it’s not just hunger. The checks are many. For instance, as the population of birds grows larger, their eggs and chicks could become a boon to some other species, that would in turn grow by preying on them. I will assume fish abundance is the only limiting factor for the sake of simplicity.
Since most birds die before reproducing, the selective pressure is intense. At this point, the species evolves towards a local optimum. It evolves towards the “seagull phenotype”, a highly optimized form for making a living by hunting small fish and crabs near the beach. The pressure is so high that some birds will develop new ways of making a living: they could, for instance, scavenge for larger animals beached on the sand, or steal fish from other birds, or hang around oceanfront restaurants to eat leftovers on the ground, or off abandoned plates. These lifestyles only account for a small fraction of the total amount of calories available to the birds. They will, however, pursue these endeavours if their main food source becomes scarce enough. Every unoccupied niche will be filled.
If the resulting behavior isolates (reproductively) a subpopulation of birds from the main population, that subpopulation may over time become a different species altogether. If the subpopulation is not reproductively isolated, however, the behavior will simply become one of a set of possible behaviors displayed by the seagulls.
This story usually describes the interaction between birds that hunt for fish (hunters) and birds that steal fish from other birds (pirates). When there are many hunters, stealing is easy and so the population of pirates grows. When there are many pirates around, stealing becomes more and more difficult. Being a pirate, like being a hunter, is a lifestyle, and it comes with a maximal theoretical population. The population of pirates stops growing when being a pirate is about as hard as being a hunter. Let us suppose the final proportion of hunters to pirates is 70% to 30%: that is called a selective equilibrium, which is a term describing two competing strategies having stabilized at a local optimum. While there are more hunters than pirates, when the selective equilibrium has been reached, it is just as hard being one as it is the other.
The story is very memorable, but it can be a little misleading. In reality, a selective equilibrium is a balance between a lot more than two distinct strategies. I enumerated a few of those above. For seagulls, the strategies could be named hunters, pirates, scavengers, beggars.
Roles also are not exclusive. It’s not like every seagull is born a hunter, or a pirate or something else. Rather, it is something like this: if 60% of the calories of an average seagull are obtained from fishing, 30% from stealing, 5% from scavenging and 5% from begging, then the average seagull will spend 60% of its time fishing, 30% of its time stealing, 5% scavenging and 5% begging, and furthermore they will do so opportunistically, not blindly. Some birds, of course, will depart from that norm to some extent and favor one strategy over another. Should one strategy become obsolete (say the fish population collapses because of another predator) those individual differences will serve as a basis for adaptive behavior (say begging) to become overall more common. However, before that happens, any seagull can use any of the strategies since they have all been selected for.
Trivially, that means pirates can give birth to hunters and vice-versa, although the offspring will tend to inherit any preference their parents might have for one strategy over another. And finally, one last point: a strategy is a way of solving a problem. In our example, the problem is how to get food, but there are other problems for a seagull, like how to reproduce, or how to react to a pirate trying to steal their fish (fight or flight?). Paternal investment vs paternal defection are examples of competing reproductive strategies. Different-problem-strategies interact together to produce very complex behavioral phenotypes.
Human societies are even more complex, but in principle everything I said about seagulls applies to us. Some of us extract calories from the environment (like hunters) and most of us in turn extract calories from society (like pirates, although usually not forcibly). We developed a variety of different strategies to that end, and most of us could fill most roles, although we might have a marked preference for one role over another. The comparison is not perfect, since our societies are much larger, and as a consequence we are much more specialized. Many roles exist that almost nobody can do, which is not the case in seagull society.
Our society has changed a lot in the last few centuries. Many roles are new. When we reach the carrying capacity of our environment, some of those will predictably disappear, but we will then progress towards our local optimum. Should the environment then stabilize, easy lifestyles will become more common (and in turn, harder) while difficult lifestyles will become more rare (and in turn, easier) until we reach the point where all lifestyles are about equally inhumane.
Implementing EPC, in other words the most reasonable form of eugenics, means introducing an artificially lower “carrying capacity”, and the effect would be mostly the same, with one important difference: the point we would reach is one where all lifestyles are about equally humane.
To some extent, either process would make society more equal. Currently, an engineer is much better paid than a baker (exceptions notwithstanding). Under EPC, all else being equal, the “engineer” strategy would be favored over the “baker” strategy… Until it’s not! The reason being an engineer is an “easy” lifestyle is in no small part because few people can or want to adopt that strategy.
That is not to say that bakers would become less numerous in an absolute sense. I am only comparing them to engineers here.
Of course, this assumes an unchanging environment, and the process is slow. In practice, it would produce some degree of convergence between different strategies, but not a complete convergence. Local optima are ever-changing, as is the environment.
To answer the original question, all that EPC can do as far as human evolution is concerned is leading us towards our current local optimum, whatever it is, and whatever it becomes.
Brittonic memetics 