On Desire: Why we want what we want P. 176
We are forced, as we have seen, to live under a system of incentives. That system — I call it our biological incentive system, or BIS for short — is wired into us. Because of it, some things, such as having sex, feel good to us and other things, such as getting burned, feel bad. We retain the ability to resist our BIS: we can, for example, act contrary to its incentives and deliberately burn ourselves, and we can refrain from having sex. Such resistance comes at a price, though. It takes willpower to refuse the rewards dangled before us by our BIS and even more willpower to submit voluntarily to its punishments.
Our BIS was imposed upon us without our consent. This might be tolerable if the force responsible for the imposition were benevolent and had our interests in mind when devising our BIS’s schedule of incentives. It would be tolerable, in particular, if this force did all it could to ensure that we had happy, meaningful lives. But this is not the case. The force in question — namely, the process of natural selection — cares little about whether we are happy and cares even less about whether we feel that our lives are meaningful. What it cares about is that we survive and reproduce. As long as our feelings of unhappiness and futility do not lessen our chances of surviving and reproducing — as long as, despite these feelings, we take the steps necessary to stay alive and have sex — the process of natural selection is indifferent to them.
Indeed, thanks to our evolutionary past, we are wired to feel dissatisfied with our human circumstances, whatever they may be. An early human who was happy with what he had — who spent his days lazing on the savannas of Africa thinking about how good life is — was far less likely to survive and reproduce than his neighbor who spent every waking moment trying to improve his situation. We, the evolutionary descendants of these humans, have inherited this predisposition toward dissatisfaction: we have a BIS that, regardless of what we have, will make us itch for more.
This, in a nutshell, is the human condition: because we have a BIS, we are forced to live under an incentive system that we did not devise, that we cannot escape, and whose incentives not only aren’t calculated to induce us to have happy, meaningful lives but will, if we respond to them, keep us in a state of dissatisfaction.”