Algorithms used by social networks show us things we've already shown interest in.
As you tend to see content online which you already agree with, over time your opinions might solidify or you might become less open-minded.
This phenomenon is known as an "echo chamber" or a "filter bubble".
We tend to agree with our friends and family.
Filter bubbles might make us unable to understand different perspectives.
Echo chambers might prevent us from being open-minded and discovering new things.
We are more likely to see content online that we have already shown an interest in.
If we click on links from a particular political party, Facebook will show you more of the same.
You can fool the algorithms by liking things you disagree with and commenting on posts you wouldn't ordinarily read.
Source: BBC Trending