Evolution and Motivational Beliefs

One of my objections to the idea that we have some sort of ‘motivational belief’ is the difficulty in squaring such an entity with our evolutionary history.

Let us assume that an entity in nature evolved a disposition to ‘do what one (believed that) one ought to do’. How would such a trait affect our evolutionary history?

Well, let’s compare two creatures; one with a belief that X1 ought to be done, and another with a belief that X2 ought to be done. Of these two creatures, the one who is going to have the most offspring is the one whose belief that X(n) ought to be done leads to the greatest genetic replication. Nature is not going to favor the creature that can most accurately identify whether X(n) really ought to be done, unless there is some necessary connection between ‘X(n) ought to be done’ and ‘A disposition to do X(n) will result in more genetic replicaIf there tion’.

This is what we see with desires. We did not evolve dispositions to desire that which is ‘intrinsically’ good in any sense of the word. We evolved dispositions to desire those things that were more likely to keep our biological ancestors alive long enough to create viable offspring. Those ancestors who did not have these desires . . . well, they are not our ancestors.

So, we have a desire for sex. Note: we do not have a desire for reproduction. Some people might have this desire but, for the most part, reproduction is an unintended and often unwanted side effect of sex. We want sex even when we do not want reproduction; thus, we look for ways of having sex while avoiding reproduction.

We have a desire to eat – and we have a taste for those foods that kept our ancestors alive long enough to raise their children to the point that those children can have grandchildren. Thus, we have a preference for high-calorie foods – fats, sugars. We do not eat so that we can stay alive. We stay alive so that we can eat.

If we had motivating beliefs, then evolution would have picked out the objects of those mental states using the same forces it used to pick out the objects of desires – according to whether pursuing that object promoted or inhibited evolutionary fitness. In other words, the objects of our motivating beliefs would be substantially the same type of things as the objects of our desires. Neither set of objects warrants being called ‘inherently valuable’ or ‘worthwhile’ more than the other.

If there are ‘intrinsic goods’ or ‘inherent value’ or ‘worthwhileness’ in the real world, evolution would have thwarted our ability to perceive them (or perceive them accurately) unless they happened to coincide with what promoted our genetic replication. If this is the case, we have no need for a concept of ‘that which has inherent value’. ‘That which, when desired, tended to promote the genetic fitness of those who desired it,” is good enough for all real-world purposes.

For all we know, there might be an inherent goodness in killing and eating one’s own children. For all we know, some of our ancestors developed a faculty for perceiving this value and responding appropriately to it. That is to say, they killed and ate all of their children. One thing we do know is that if this ever was the case, those who can perceive this inherent value correctly would not be our ancestors. We have a better chance of being descendent from ancestors who had a perverse reaction to the inherent value of eating one’s own children and, as a result of this perversion, shunned the practice, and protected their children instead.

So, my question for those who hold that we have somehow evolved the capacity to have motivational beliefs is to explain how this capacity evolved and how it remained uncorrupted by evolutionary forces, given the effect that different motivational beliefs would have on genetic fitness.

Beliefs are mental states that fit the state to the world, such that if a belief does not correspond to the world then the belief should change. We can tell an evolutionary story of the value of matching beliefs to the world. The lion who does not believe that there is an antelope when there are antelopes will starve. The antelope who does not believe that there are lions where there are lions will become dinner. There are consequences when our beliefs about the world around us are untrue, which suggests that there are forces that aim to make our beliefs increasingly reliable – at least in those areas relevant to our genetic replication.

We also have a story to tell about desires. We have evolutionary stories to tell about the evolution of a desire to have sex, a desire to care for one’s children, a desire to eat high calorie foods, a desire for an environment that is not too warm or not too cold, an aversion to pain, and a disposition to feel pain when confronted with states of affairs that threaten our genetic fitness.

We even have an evolutionary story to tell about the malleability of our brains. If you hard-wire a brain for a particular environment, then the being with that brain is going to have a terrible time of it when that environment changes. The being that will survive environmental changes is the being whose brain changes to generate behavior that is appropriate in the new environment. The brain must not only change, but it must make the right types of changes. This means that it must be a brain that determines its shape as a result, not of genetic hardwiring, but as a result of interaction with the environment. In other words, it learns how to behave.

It is difficult (impossible) to come up with a similar story for motivational beliefs about worthwhileness.

The first question is whether there is anything in the real world essential to our survival that has worthwhileness to fix the beliefs to. If the beliefs do not have anything to fix to, then the fact that these are supposed to be motivational beliefs creates a problem. Without an anchor relevant to survival, evolution will fix these motivational beliefs on the same type of things that it fixes desires to – things that tend to promote the genetic replication of the agent. Agents may view these things as having ‘worthwhileness’, but the objects are, nonetheless, the same class of objects that desires point to, and for the same reasons (because those motivated to pursue these ends survive and have offspring).

Or, better yet, stick with the standard types of beliefs and desires, and treat ‘worthwhileness’ as a false belief in intrinsic values, blended with the realization that people generally have reason to promote those desires that tend to fulfill other desires, and inhibit desires that tend to thwart other desires.

Now, I fully recognize that evolution is not guided by any sort of sense. Evolution can promote traits that serve no purpose, and even promote harmful traits. This may be the case with motivational beliefs. However, in those types of cases, we are talking about traits that we can observe. We know that they exist, and our job is to explain them. When we talk about motivational beliefs, about things for which there is no strong evidence, an argument like the one presented here suggests that such a search would probably turn up nothing.

If somebody comes to me and says that he saw a ghost, I do not need to come up with a theory that explains what he thinks he saw without making mention of a ghost. All I have to do is point out how utterly bizarre it would be for ghosts to exist. From this I can infer that there probably is a logical explanation for what the agent thinks was a ghost, without mentioning ghosts.

That is, unless I was a character in a Hollywood script or book. If that were the case, then having a character come up to me claiming that he saw a ghost should be taken as good evidence that he really has seen a ghost – because the author has almost certainly written ghosts into the world where the story takes place. However, since I am not a character in a work of fiction (as far as I can determine), I discount ghost claims, without going to the effort of providing an alternative explanation for every ghost claim ever made.

The same is true of my skepticism of ‘motivational belief’ claims.