Tag Archives: Selection effect

SIA on other minds

Another interesting implication if the self indication assumption (SIA) is right is that solipsism is much less likely correct than you previously thought, and relatedly the problem of other minds is less problematic.

Solipsists think they are unjustified in believing in a world external to their minds, as one only ever knows one’s own mind and there is no obvious reason the patterns in it should be driven by something else (curiously, holding such a position does not entirely dissuade people from trying to convince others of it). This can then be debated on grounds of whether a single mind imagining the world is more or less complex than a world causing such a mind to imagine a world.

The problem of other minds is that even if you believe in the outside world that you can see, you can’t see other minds. Most of the evidence for them is by analogy to yourself, which is only one ambiguous data point (should I infer that all humans are probably conscious? All things? All girls? All rooms at night time?).

SIA says many minds are more likely than one, given that you exist. Imagine you are wondering whether this is World 1, with a single mind among billions of zombies, or World 2, with billions of conscious minds. If you start off roughly uncertain, updating on your own conscious existence with SIA shifts the probability of world 2 to billions of times the probability of world 1.

Similarly for solipsism. Other minds probably exist. From this you may conclude the world around them does too, or just that your vat isn’t the only one.

SIA doomsday: The filter is ahead

The great filter, as described by Robin Hanson:

Humanity seems to have a bright future, i.e., a non-trivial chance of expanding to fill the universe with lasting life. But the fact that space near us seems dead now tells us that any given piece of dead matter faces an astronomically low chance of begating such a future. There thus exists a great filter between death and expanding lasting life, and humanity faces the ominous question: how far along this filter are we?

I will argue that we are not far along at all. Even if the steps of the filter we have already passed look about as hard as those ahead of us, most of the filter is probably ahead. Our bright future is an illusion; we await filtering. This is the implication of applying the self indication assumption (SIA) to the great filter scenario, so before I explain the argument, let me briefly explain SIA.

SIA says that if you are wondering which world you are in, rather than just wondering which world exists, you should update on your own existence by weighting possible worlds as more likely the more observers they contain. For instance if you were born of an experiment where the flip of a fair coin determined whether one (tails) or two (heads) people were created, and all you know is that and that you exist, SIA says heads was twice as likely as tails. This is contentious; many people think in such a situation you should think heads and tails equally likely. A popular result of SIA is that it perfectly protects us from the doomsday argument. So now I’ll show you we are doomed anyway with SIA.

Consider the diagrams below. The first one is just an example with one possible world so you can see clearly what all the boxes mean in the second diagram which compares worlds. In a possible world there are three planets and three stages of life. Each planet starts at the bottom and moves up, usually until it reaches the filter. This is where most of the planets become dead, signified by grey boxes. In the example diagram the filter is after our stage. The small number of planets and stages and the concentration of the filter is for simplicity; in reality the filter needn’t be only one unlikely step, and there are many planets and many phases of existence between dead matter and galaxy colonizing civilization. None of these things are important to this argument.


Diagram key


The second diagram shows three possible worlds where the filter is in different places. In every case one planet reaches the last stage in this model – this is to signify a small chance of reaching the last step, because we don’t see anyone out there, but have no reason to think it impossible. In the diagram, we are in the middle stage, earthbound technological civilization say. Assume the various places we think the filter could be are equally likely..

SIA doom


This is how to reason about your location using SIA:

  1. The three worlds begin equally likely.
  2. Update on your own existence using SIA by multiplying the likelihood of worlds by their their population. Now the likelihood ratio of the worlds is 3:5:7
  3. Update on knowing you are in the middle stage. New likelihood ratio: 1:1:3. Of course if we began with an accurate number of planets in each possible world, the 3 would be humungous and we would be much more likely in an unfiltered world.

Therefore we are much more likely to be in worlds where the filter is ahead than behind.


Added: I wrote a thesis on this too.

A status theory of blog commentary

Commentary on blogs usually comes in two forms: comments there and posts on other blogs. In my experience, comments tend to disagree and to be negative or insulting much more than links from other blogs are. In a rough count of comments and posts taking a definite position on this blog, 25 of 35 comments disagreed, while 1 of 12 posts did, even if you don’t count another 11 posts which link without comment, a seemingly approving act. Why is this?

Here’s a theory. Lets say you want status. You can get status by affiliating with the right others. You can also get status within an existing relationship by demonstrating yourself to be better than others in it. When you have a choice of who to affiliate with, you will do better not to affiliate at all with most of the people you could demonstrate your superiority to in a direct engagement, so you mostly try to affiliate with higher status people and ignore or mock from a distance those below you. However when it is already given that you affiliate with someone, you can gain status by seeming better than they.

These things are supported if there is more status conflict in less voluntary relationships than in voluntary ones, which seems correct. Compare less voluntary relationships in workplaces, schoolgrounds, families, and between people and employees of organizations they must deal with (such as welfare offices) with more voluntary relationships such as friendships, romantic relationships, voluntary trade, and acquaintanceships.

This theory would explain the pattern of blog commentary. Other bloggers are choosing whether to affiliate with your blog, visibly to outside readers. As in the rest of life, the blogger would prefer to be seen as up with good bloggers and winning stories than to be bickering with bad bloggers, who are easy to come by. So bloggers mostly link to good blogs or posts and don’t comment on bad ones.

Commenters are visible only to others in that particular comments section. Nobody else there will be impressed or interested to observe that you read this blogger or story, as they all are. So the choice of whether to affiliate doesn’t matter, and all the fun is in showing superiority within that realm. Pointing out that the blogger is wrong shows you are smarter than they, while agreeing says nothing. So commenters tend to criticize where they can and not bother commenting on posts they agree with.

Note that this wouldn’t mean opinions are shaped by status desire, but that there are selection effects so that bloggers don’t publicize their criticisms and commenters don’t publicize what they like.

Generous people cross the street before the beggar

Robert Wiblin points to a study showing that the most generous people are the most keen to avoid situations where they will be generous, even though the people they would have helped will go without.

We conduct an experiment to demonstrate the importance of sorting in the context of social preferences. When individuals are constrained to play a dictator game, 74% of the subjects share. But when subjects are allowed to avoid the situation altogether, less than one third share. This reversal of proportions illustrates that the influence of sorting limits the generalizability of experimental findings that do not allow sorting. Moreover, institutions designed to entice pro-social behavior may induce adverse selection. We find that increased payoffs prevent foremost those subjects from opting out who share the least initially. Thus the impact of social preferences remains much lower than in a mandatory dictator game, even if sharing is subsidized by higher payoffs…

A big example of generosity inducing institutions causing adverse selection is market transactions with poor people.

For some reason we hold those who trade with another party responsible for that party’s welfare. We blame a company for not providing its workers with more, but don’t blame other companies for lack of charity to the same workers. This means that you can avoid responsibility to be generous by not trading with poor people.

Many consumers feel that if they are going to trade with poor people they should buy fair trade or thoroughly research the supplier’s niceness. However they don’t have the money or time for those, so instead just avoid buying from poor people. Only the less ethical remain to contribute to the purses of the poor.

Probably the kindest girl in my high school said to me once that she didn’t want a job where she would get rich because there are so many poor people in the world. I said that she should be rich and give the money to the poor people then. Nobody was wowed by this idea. I suspect something similar happens often with people making business and employment decisions. Those who have qualms about a line of business such as trade with poor people tend not to go into that, but opt for something guilt free already, while the less concerned do the jobs where compassion might help.

Charitable explanation

Is anyone really altruistic? The usual cynical explanations for seemingly altruistic behavior are that it makes one feel good, it makes one look good, and it brings other rewards later. These factors are usually present, but how much do they contribute to motivation?

One way to tell if it’s all about altruism is to invite charity that explicitly won’t benefit anyone. Curious economists asked their guinea pigs for donations to a variety of causes, warning them:

“The amount contributed by the proctor to your selected charity WILL be reduced by however much you pass to your selected charity. Your selected charity will receive neither more nor less than $10.”

Many participants chipped in nonetheless:

We find that participants, on average, donated 20% of their endowments and that approximately 57% of the participants made a donation.

This is compared to giving an average of 30-49% in experiments where donating benefited the cause, but it is of course possible that knowing you are helping offers more of a warm glow. It looks like at least half of giving isn’t altruistic at all, unless the participants were interested in the wellbeing of the experimenters’ funds.

The opportunity to be observed by others also influences how much we donate, and we are duly rewarded with reputation:

Here we demonstrate that more subjects were willing to give assistance to unfamiliar people in need if they could make their charity offers in the presence of their group mates than in a situation where the offers remained concealed from others. In return, those who were willing to participate in a particular charitable activity received significantly higher scores than others on scales measuring sympathy and trustworthiness.

This doesn’t tell us whether real altruism exists though. Maybe there are just a few truly altruistic deeds out there? What would a credibly altruistic act look like?

Fortunately for cute children desirous of socially admirable help, much charity is not driven by altruism (picture: Laura Lartigue)

Fortunately for cute children desirous of socially admirable help, much charity is not driven by altruism (picture: Laura Lartigue)

If an act made the doer feel bad, look bad to others, and endure material cost, while helping someone else, we would probably be satisfied that it was altruistic. For instance if a person killed their much loved grandmother to steal her money to donate to a charity they believed would increase the birth rate somewhere far away, at much risk to themselves, it would seem to escape the usual criticisms. And there is no way you would want to be friends with them.

So why would anyone tell you if they had good evidence they had been altruistic? The more credible evidence should look particularly bad. And if they were keen to tell you about it anyway, you would have to wonder whether it was for show after all. This makes it hard for an altruist to credibly inform anyone that they were altruistic. On the other hand the non-altruistic should be looking for any excuse to publicize their good deeds. This means the good deeds you hear about should be very biased toward the non-altruistic. Even if altruism were all over the place it should be hard to find. But it’s not, is it?