Bandwagon effect
The bandwagon effect is adopting a belief or behavior because many other people are doing it. Popularity starts to feel like proof that something is right or good.
In everyday life
Someone buys shares in a company only because everyone at work is talking about it, right as the price peaks.
You had no opinion about a new TV series, but once most of your friends rave about it online, you start calling it the best show of the year after seeing only one episode.
Why your mind does this
We rarely have full information about a person or situation, so the brain fills gaps with what usually holds true for similar cases. Relying on categories, rules of thumb and trusted sources saves a huge amount of time and effort. For most of history, following the group and trusting experienced elders was a safe bet.
How to spot it
Ask whether you would still hold this view if you were the only person who held it.
How to counter it
Write down your own reasons for a choice before looking at what others have picked.
Same family: Stereotypes
SourcesLeibenstein (1950)·Wikipedia