Here’s a consideration in the opposite direction (and which could imply positive average welfare a priori, depending on your subjective credences), which I had written about here (and then forgot when I wrote this post):
However, I also suspect there’s an argument going in the opposite direction (is it the same as the original one in the OP?): animals act to avoid suffering and seek pleasure, and the results might better be thought of as applying to behaviours in response to pleasure and suffering as signals than directly to these signals, because evolution is optimizing for behaviour, and optimizing for pleasure and suffering only as signals for behaviour. If we thought a negative event and a positive event were equally intense, probable and reinforcing *before* they happened, the positive event would be more likely to continue or happen again after it happened than the negative one after it happened, because the animal seeks the positive and avoids the negative. This would push the average welfare up. I’m pretty uncertain about this argument, though.
Indeed, you could think of humans as the most extreme and successful example of this, given how much effort we’ve put in to reduce suffering and discomfort and increase pleasure.
Here’s a consideration in the opposite direction (and which could imply positive average welfare a priori, depending on your subjective credences), which I had written about here (and then forgot when I wrote this post):
Indeed, you could think of humans as the most extreme and successful example of this, given how much effort we’ve put in to reduce suffering and discomfort and increase pleasure.