Sometimes people argue that pain and suffering should be expected to overwhelm the world because bad experiences are ‘stronger’ in some sense than good ones. People generally wouldn’t take five minutes of the worst suffering they have ever had for five minutes of the best pleasure (or so I’m told). An evolutionary explanation sometimes given is that the things that happen to animals tend to be mildly beneficial for them most of the time, then occasionally very bad. For instance, eating food is a bit good, but one meal won’t guarantee you evolutionary success. If on the other hand someone else eats you, you have lost pretty badly.
This seems intuitively plausible. Many processes have the characteristic that you can add more bricks and gradually reach your goal, but taking away a brick causes the whole thing to crumble. However good and bad outcomes are relative. If you see a snake and are deciding whether to go near it or not, there is a worse outcome of it biting you, and a better outcome of it not biting you. The good outcome here is super valuable, even if it doesn’t buy you immediate evolutionary success. It is just as important for you to get the good outcome as for you to not get the bad outcome. So what exactly do we mean by bad outcomes being worse than good outcomes are good? It seems we are judging outcomes relative to some default. So we need an explanation for why the default is where it is.
I think the most obvious guess is that the default is something like expectations, or ‘business as usual’. If you generally expect to go through your morning not being killed, then the avoiding being bitten by the snake option is close to neutral, whereas the being bitten option is very bad. But if the default is expectations, then the expected badness and the expected goodness should roughly cancel out – if suffering just tends to be stronger, then it should also tend to be rare enough to cancel. So on this model you shouldn’t expect life to be net bad especially.
At least on this model the badness and goodness should have cancelled out in the evolutionary environment. Our responses to good and bad situations don’t seem to change with our own expectations that much – even if you have been planning to go to the dentist for months, and it isn’t as bad as you thought, it can still be pretty traumatic. So you might think the default is fairly stable, and after we have been pushed far from our evolutionary environment, joy and suffering could be out of balance. Since we have been the ones pushing ourselves from the evolutionary environment, you might think we have been pushed basically in the direction of things we like (living longer, avoiding illness and harsh physical conditions, minimizing hard labor). So you might expect it is out of balance in the direction of more joy.
This story has some gaps. Why would we experience positive and negative emotions relative to rough expectations? Is the issue really expectations, or just something that looks a bit like that? To answer these questions one would seem to need a much better understanding of the functions of emotional reactions than I have. For now though, a picture where positive and negative emotions were roughly equal in some sense at some point seems plausible, and on that picture, I expect they are now net positive for humans, and roughly neutral for animals (by that same measure). This contribute to my lack of concern for both wild animal suffering, and the possibility that human lives are broadly not worth living.
There are many further issues unresolved. The notion that pleasure and pain should be roughly balanced for some reason is given much of its intuitive support by the observation that they are close enough that which is greater seems somewhat controversial. But perhaps net pleasure and pain only seem to be broadly comparable because humans are bad at comparing things, especially nebulous things. It is not uncommon to be both unclear on whether to go to school A or school B, and also unclear on whether you should go to school A with $10,000 or school B. Another issue is whether the measure by which there were similar amounts of pleasure and suffering actually align with your values. Perhaps positive and negative emotions use similar amounts of total mental energy, but mental energy translates to experiences you like more efficiently than to ones you don’t. Another concern is whether animals in general should be in such an equilibrium, or whether perhaps only animals that survive should, and all the offspring produced that die immediately don’t come into the calculus and can just suffer wantonly.
I think it is hard to give a conclusive account of this issue at the moment, but as it stands I don’t see how evolutionary considerations suggest we should expect bad feelings to dominate.