These appear to be classic “double blind” types of experiments. If experiments were conducted where somebody knew the other person or whatever, that would not really fit the description and might not pass peer review.
But I understand what you are saying.
The author makes some interesting observations and speculations that extroverted people seem to perform better than introverted ones.
It’s an interesting study but I am not sure the effect was statistically significant. The key here will be repetition.
I’m far more inclined to believe in this than I am UFOs.
One interesting experience I had was finding some money a girlfriend had hidden in a book some 150 miles away. I had a dream that she had hidden some money in a book. The next day when I got to her house she said that she had to go through all the books in her headboard because she had hidden some money there but couldn’t remember which book. (From her thieving teenage brother who lived with her) I pulled the book I had seen in my dream out of the headboard, flipped through it and found the money.
I think people who are close become connected in some way.