Wiki seems to say it could go either way.
All hail the almighty public opinion!
Don't worry, everybody knows the almighty Zanzibar opinion is beyond anything the mere public could possibly conceive as right...

And what exactly are you guys talking about? Psychology and Chemistry and the other sciences all have the EXACT same methods of proving 'fact'.
Example:
Chemistry - You give someone a dose of Adrenalin, monitor them and take down the results, and conclude that adrenalin increases blood pressure, heightens senses, etc. Repeat 1000 times and you record it as a fact.
Psychology - You lock a subject and a bunch of others in a room and force them to count beats. There's 11 beats in total. Afterwards, a man comes in and asks them each how many beats they heard. Each person says '12', so when the subject is finally asked he also says '12', proving that social pressure can effect people's core beliefs (i.e. how many beats they perceived) Repeat 1000 times and you record it as fact.
Naturally, there will people who stick to their beliefs even though 9 people before them all heard differently, just like there are people who aren't effected by adrenalin. But the majority are for both.
Where's the difference? Why is it not a fact, simply because it concerns the mental and not the physical?