EDIT
 Compressing Reality

# Echo Chambers

An echo chamber is when people of the same beliefs get together and tell each other that they’re right and prevent alternative views from being discussed "title": "Echo chamber (media)". As I’ve mentioned, the question is not whether echo chambers exist, but to what extent they exist.

## Do They Exist

Anecdotally, I suspect most of you who are on Facebook have seen links that show you all your friends who “liked" Donald Trump’s facebook page. Inevitably, immediately beneath there are a string of comments where people claim that none of their friends have “liked” Trump.

Trump’s facebook page "title": "Donald J. Trump" has 4.75 million likes. Facebook has 156.5 million users in the United States "title": "Pick best social media for you ... with cats". Assuming that all Trump likers are in the US, this means that 3.04% of Facebook users “like” Trump.

The median Facebook user has 200 friends "title": "Do You Have Too Many Facebook Friends?" (the mean user has 338). The odds that a median user has zero Trump-liking friends assuming one’s politics and friends do not correlate are 480-to-1. In other words, the odds would be that the average user doesn’t even have a friend who has no Trump friends.

So, there is little doubt that we are seeing some degree of an echo chamber here. How much of one? Well, your mileage may vary. If you have have 200 friends and not a single one is a Trump-liker, then (using an uninformative "title": "Prior probability" conjugate prior "title": "Conjugate prior") we can estimate that you are 6 times as likely to befriend a Trump-not-liker compared to a Trump-liker.

So echo chambers definitely exist on Facebook.

In the real world, a poll found that 47% of Clinton supporters and "31% of Trump supporters, say they have no close friends who support the opposing candidate" "title": "Few Clinton or Trump Supporters Have Close Friends in the Other Camp" Likewise, 44% of Trump supporters and 41% of Clinton supporters say they have "a lot" of close friends who support their canddiate. The other two options were "some" and "just a few" friends.

## Causes

The most obvious cause of echo chambers is self-selection. Both consciously and unconsciously, most people don’t like to be given evidence against their beliefs "title": "Confirmation bias".

There are other causes though. For instance, many demographic factors correlate with various aspects of political ideology in the United States "title": "Political ideologies in the United States". So, it is likely that when people try to live, work, and play with people who are similar to themselves in terms of income, education, religious beliefs, etc, they inadvertantely promote certain political beliefs.

Finally, there is significant social pressure to conform "title": "Asch conformity experiments". If you’re with a group of others and one of them says they believe X, but you believe Y, then there isn’t much pressure to keep silent. But if two or three people all support X, I know I start feeling uneasy voicing an opposing opinion. Some science supports the idea that I’m hardly unique in that respect "title": "Social Media and the ‘Spiral of Silence’". I’m certainly not alone in thinking that social media only escalates this problem "title": "How Social Media Silences Debate".

## So What?

I can think of several reasons this is problematic.

1. There is always the chance that you’re wrong and need exposure to alternative points of view to realize that.
2. There is always the chance that They are wrong, and they need exposure to alternative points of view to realize that. Remember, if all liberals unfriend all Trump supporters, Trump supporters will only talk to themselves.
3. Exposure to people of different races increases our empathy towards others "title": "How Diversity Makes Us More Empathetic". I suspect a similar idea might apply to political identities.
4. Echo chambers tend to promote us-versus-them thinking, which is unproductive in getting effective legislation passed.
5. On a meta-level, you better hope that when you find yourself believing something off the beaten path, people will still accept you for (or at least inspite of) it.

What's the solution?

It's not that complicated. In addition to the generally good advice about keeping an open mind, its important to be able to accept someone despite of their political beliefs. Indeed opposing political beliefs can actaully be viewed as a bonus, because it could make you more empathetic, demonstrate you are wrong (hurray!), or might allow you to (nicely) spread some good ideas to someone new.

In short, don't unfriend someone for supporting Donald Trump. If someone expresses bad ideas, they should be shown an alternative idea backed up with reason and evidence - not threatened with social ﻿ostracization.