Related: Fake Selfishness, Not for the Sake of Pleasure Alone, Not for the Sake of Happiness (Alone), Value is Fragile, Fake Fake Utility Functions

No one deserves thanks from another about something he has done for him or goodness he has done. He is either willing to get a reward from God, therefore he wanted to serve himself. Or he wanted to get a reward from people, therefore he has done that to get profit for himself. Or to be mentioned and praised by people, therefore, it is also for himself. Or due to his mercy and tenderheartedness, so he has simply done that goodness to pacify these feelings and treat himself.

- Mohammed Ibn Al-Jahm Al-Barmaki

In a 1990 experiment, Jack Dovidio made subjects feel empathy for a young woman by asking subjects to imagine what she felt as she faced a particular problem.¹ Half the subjects focused on one problem faced by the woman, while the other half focused on a different problem she faced. When given the opportunity to help the woman, subjects in the high empathy condition were more likely to help than subjects in the low empathy condition, and the increase was specific to the problem that had been used to evoke empathy.

What does this study say about altruism and selfishness?

Some people think that humans are purely selfish, that we act for selfish motives alone. They will re-interpret any counter-example you give ("But wouldn't you sacrifice your life to save the rest of the human species?") as being compatible with purely selfish motives.

Are they right? Do we act for selfish motives alone?

Let's examine the evidence.²

We begin with a rough sketch of human motivation. We have 'ultimate' desires: things we desire for their own sake. We also have 'instrumental' desires: things we desire because we belief they will satisfy our ultimate desires.

I instrumentally desire to go to the kitchen because I ultimately desire to eat a brownie and I believe brownies are in the kitchen. But if I come to believe brownies are in the dining room and not the kitchen, I will instrumentally desire to walk to the dining room instead, to fulfill my ultimate desire to eat a brownie. Or perhaps my desire to eat a brownie is also an instrumental desire, and my ultimate desire is to taste something sweet, and I instrumentally desire to eat a brownie because I believe that eating a brownie will satisfy my desire to taste something sweet.

Of course, desires compete with each other. Perhaps I have an ultimate desire to taste something sweet, and thus I instrumentally desire to eat a brownie. But I also have an ultimate desire for regular sex, and I believe that eating a brownie will contribute to obesity that will lessen the chances of satisfying my desire for regular sex. In this case, the 'stronger' desire will determine my action.

The full picture is more complicated than this,³ but we only need a basic picture to assess the claim that we only act for selfish motives alone.

We might categorize ultimate desires like this:⁴

Psychological egoists think all ultimate desires are of type 2. Psychological hedonists are a subset of egoists who think that all ultimate desires are of type 1. Psychological altruists think that at least some ultimate desires are of type 4. If some ultimate desires are of type 3, but none are of type 4, then both egoism and altruism are false.

Previously, I presented neurobiological evidence that psychological hedonism is false. In short: desire and pleasure are encoded separately by the brain, and we sometimes desire things that are not aimed at producing pleasure, and in fact we sometimes desire things that do not produce pleasure when we get them.

But can we also disprove the claim that we act for selfish reasons alone (psychological egoism), by showing that normal humans have desires for the well-being of others?