When someone tells me that all human action is motivated by the desire for pleasure, or that we can solve the Friendly AI problem by programming a machine superintelligence to maximize pleasure, I use a two-step argument to persuade them that things are more complicated than that.

First, I present them with a variation on Nozick's experience machine,¹ something like this:

Suppose that an advanced team of neuroscientists and computer scientists could hook your brain up to a machine that gave you maximal, beyond-orgasmic pleasure for the rest of an abnormally long life. Then they will blast you and the pleasure machine into deep space at near light-speed so that you could never be interfered with. Would you let them do this for you?

Most people say they wouldn't choose the pleasure machine. They begin to realize that even though they usually experience pleasure when they get what they desired, they want more than just pleasure. They also want to visit Costa Rica and have good sex and help their loved ones succeed.

But we can be mistaken when inferring our desires from such intuitions, so I follow this up with some neuroscience.

Wanting and liking

It turns out that the neural pathways for 'wanting' and 'liking' are separate, but overlap quite a bit. This explains why we usually experience pleasure when we get what we want, and thus are tempted to think that all we desire is pleasure. It also explains why we sometimes don't experience pleasure when we get what we want, and why we wouldn't plug in to the pleasure machine.

How do we know this? We now have objective measures of wanting and liking (desire and pleasure), and these processes do not always occur together.

One objective measure of liking is 'liking expressions.' Human infants, primates, and rats exhibit homologous facial reactions to pleasant and unpleasant tastes.² For example, both rats and human infants display rhythmic lip-licking movements when presented with sugary water, and both rats and human infants display a gaping reaction and mouth-wipes when presented with bitter water.³

Moreover, these animal liking expressions change in ways analogous to changes in human subjective pleasur...

poh1ceko

poh1ceko

poh1ceko

poh1ceko