Why do people think 2+1=4, when its really 3?

Question

explain

Answer 1

uhh because either they were tuaght like that of they believed it...

Answer 2

if it makes money, people will believe anything

Answer 3

People are able to be controlled, people might think 2+1=4 because that's what someone told them to believe.  It's just like the book 1984, by George Orwell, when I read it, that's when I figured it out... that somebody can be controlled to think that.

Answer 4

Well if it is for an experiment like Asch's line experiment,  I could understand how people could think that. Where the experimenter would tell everyone to answer 4, and only one person would be out of the loop. Then that one person would go with 4 because of him or her doesn't want to go against the group. But then again, I don't know if that is the answer you were actually looking for.