Irrationality or Gustibus?

de gustibus non disputandum
(there’s no accounting for taste)

Can Eliezer’s reasoning about lotteries be extended to something like sexuality? The goal of our sex drives is reproduction of the fittest members of the species. But today we have interrupted this process so that most sexuality does not lead to reproduction. The underlying logic of the drive is no longer functional. Does this mean that our sex desires are irrational, and that we should consider sex to be as pernicious and harmful as lotteries?

Another example is our love of sweet and fatty foods, which are harmful to our health in today’s environment. The fundamental reasons we seek these foods no longer apply today. In a sense, this kind of hunger is irrational, in that satisfying the drive is actually harmful to us.

Where do we draw the line in judging whether our desires are rational?

Most of our discussions of bias here relate to beliefs about truth. A bias gives us an incorrect view of the truth, and we seek to overcome the bias so that we can see the truth more clearly.

But there is a larger and more inclusive sense in which we can look deeper for biases in our motivations and goals. This requires us to adopt a model where different parts of our minds have their own individual goals, which may be in conflict. One part (or more parts) of our minds is the talking part, and that is who is writing here. Our discussions are primarily among the talking parts. It somewhat goes without saying that the goals we discuss as most important are the goals of our talking parts.

From this perspective, one part of our minds, the talking part, can judge the goals and methods used by other parts, by its own standards. Our talking parts favor logic and rationality. They want to see that the goals of a system are effectively being achieved by the means it employs. And by this standard, other parts of our minds fall short. Our sexuality does not achieve its goal of reproduction. Our hunger does not achieve its goal of health. Our love of risk does not achieve its goal of proportional reward.

We can identify these failures as biases and perhaps seek to overcome them. It is likely to be more difficult than mere failures to perceive truth, via logical illusions and constrained rationality. Our drives are deep and powerful, and even if they are ultimately pointless that does not take away their power. But I would suggest that it does make sense to hold our evolutionary drives up for analysis and judgment at least in the terms proposed here, whether they achieve their goals in today’s environment. If not, we should try to overcome these ultimately pointless or even harmful urges.