On the topic of “why would conformity not grow with 15 people going before you instead of 3”, one answer is obvious. The subject realises that the other people are not independently wrong, but that their is a trick. A Baysian can reason that other people might not be independent data points.
In my school I volunteered with the psychology class to help with an experiment. The first person said line C was the matching one, I practically flinched, and gave them an involuntary “what is wrong with you?” look. The second agreed it was line C. I thought “what the hell?!!” and looked at their sheet, then back and my sheet and confirmed they were the same. On person 3 I realised I could fold my sheet over and hold it to the light to check they lined up. If I had been the 4th in the line I would have been really confused. But I was something like 12th. By person 7 I was almost 100% sure the play was “Oh, they must all be in on it somehow. They want to see if peer pressure will turn me into an idiot.”
So an unavoidable issue with the experiment is that more people conforming gives the subject more time to theorise about why a large cohort of people would all be making such an obvious mistake in a correlated way. And this theorising will not take long to start focussing on the fact that you know its an experiment, and you start wondering what they could be testing.
I was about to add on that no-one would ever conform if they had even the slightest real reward for pointing out the obvious (eg. some $ for a right answer), but a quick google suggests that my intuitions on that might be really out.
On the topic of “why would conformity not grow with 15 people going before you instead of 3”, one answer is obvious. The subject realises that the other people are not independently wrong, but that their is a trick. A Baysian can reason that other people might not be independent data points.
In my school I volunteered with the psychology class to help with an experiment. The first person said line C was the matching one, I practically flinched, and gave them an involuntary “what is wrong with you?” look. The second agreed it was line C. I thought “what the hell?!!” and looked at their sheet, then back and my sheet and confirmed they were the same. On person 3 I realised I could fold my sheet over and hold it to the light to check they lined up. If I had been the 4th in the line I would have been really confused. But I was something like 12th. By person 7 I was almost 100% sure the play was “Oh, they must all be in on it somehow. They want to see if peer pressure will turn me into an idiot.”
So an unavoidable issue with the experiment is that more people conforming gives the subject more time to theorise about why a large cohort of people would all be making such an obvious mistake in a correlated way. And this theorising will not take long to start focussing on the fact that you know its an experiment, and you start wondering what they could be testing.
I was about to add on that no-one would ever conform if they had even the slightest real reward for pointing out the obvious (eg. some $ for a right answer), but a quick google suggests that my intuitions on that might be really out.