1. Yep. But I don't "use" people I interact/will interact in a daily basis (like online friends and people from a forum). I'll most likely sign up in a penpal site, do and advanced search, contact X people that matche the criteria and wait for responses. If they're interesting, I tell them I anted to prove something and then befriend them. If they don't interest me, I stop talking to them. In real life I test hypothesis with people I don't care about, not with friends (I ask friends "what they'd say if I told them that...", but they just know it's me being curious about something I'm wondering). If I'm feeling extroverted that day, I approach people in the street, or react in certain way to see how THEY react, but that seldom happens.
2. Weeeeell, it depends. My parents say I was born skeptical of everything, and I'm a big statistic haters, because it's said that they're an accurate representation of the society, but I sort of mistrust this. If I make a survey online, I'll be expecting the survey to be replied by people who have access to the internet, people who want to take the survey, people who found that survey. If I stop on one city corner and start asking questions to people, it will be to people willing to answer questions, who are walking, whose path includes that corner, people passing at that particular time, etc etc etc. Even if I choose random people from any street, it will be according to me saying "yes to this one, no to that one", so it's always according to some criteria.
Having said that, when I do make these tests, I find results that I choose to consider accurate because they come from experience and I trust my ability to design questions or have certain reactions that will lead me to specific answers.
Example: a couple months ago, there was this guy from UNESCO outside some shop, trying to get people to monthly donate money (via direct debit). He "caught" me and started telling me about whatever cause it was. I can't remember because he was standing painfully close to me and as he was taller than me, he was sort of... wrapping me with his body without touching me. Plus, he would look at me in the eyes without blinking. I just wanted to get the hell out. At one moment I pushed him away and asked him how many people he had convinced with that attitude. He said "none", so I grabbed the folder he had and went to random people on the street and told them the same thing he had told me (I tried to use to my slight knowledge of micro-expressions I had been learning). In less than half an hour I had 5 people willing to donate, so I gave the folder back to the guy and decided to go back home. He asked me if I was going to donate, and I told him some shit about me only trusting their concern about equality when the UN decided not to have countries with veto power and went away.
3. I'm concerned about being myself with people that I see every day or that already know me, or that I care about. If I need to prove a point and I need of people I don't know or care about, I don't care playing the part.
