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".
Tend
We tend to agree with our friends and family.
Unable
Filter bubbles might make us unable to understand different perspectives.
Open-minded
Echo chambers might prevent us from being open-minded and discovering new things.
Likely
We are more likely to see content online that we have already shown an interest in.
Links
If we click on links from a particular political party, Facebook will show you more of the same.
Fool
You can fool the algorithms by liking things you disagree with and commenting on posts you wouldn't ordinarily read.
Source: BBC Trending