Testing for psychological effects can be very subtle, and psychologists often have trouble with experimental design, which is why they spend so much time studying it in their training. Here’s an example from when I was a science student, and my roommate was an experimental psych major.

We used to meet in the university coffee shop every day at a time when both of us were between classes. On one particular day, I brought the styrofoam cups of black coffee to the table, along with two packets of sugar and two of cream, as well as little wooden stirrers (we both drank our coffee sweet and light). I poured the cream and sugar in each cup and was about to stir them when he stopped me.

“Don’t!”, he said. “Those little wooden sticks are full of oils and resins that give the coffee a funny taste. Let me go get some plastic spoons to stir with.”

“Rubbish”, I replied. “There’s nothing in those sticks that you can taste. And I’ll prove it to you. Let me stir one cup with a stick, and the other with plastic while you look the other way. Then taste them both and tell me which is which”

Sure enough. We performed the experiment, and he could not tell the two apart. They tasted the same. Whatever alleged differences they might have had, were below his level of perception.

Immediately, he protested. “This experiment is not properly controlled. Even though the coffee came from the same pot, there may have been slight differences in the amounts of cream and sugar in those packets, so the cups are not identical, so testing for the presence of stick cannot be done properly if there are other differences which would affect the taste, and hence, the result.”

I answered that we were not testing for sweetener or cream. We were testing for stick. One cup could have been black and sweet, and the other light but unsweetened, and he still should have been able to detect “stick”, which is what he was claiming. In fact, one cup could have been coffee and the other tea or soup, in this type of test a “control” was irrelevant. Or if you prefer, the cup stirred with plastic was the “control”, regardless of what was in it. I never could get him to see the distinction.

Psych majors; they are so obsessed with the formal design of an experiment, and getting the nomenclature right, that they forget why we do experiments in the first place. It also suggests that the methods of physical science are inappropriate when studying non-physical phenomena; which further suggests that there are a lot of very important questions and issues that cannot be settled by blindly applying the methods and protocols of hard science.

You can convince yourself of any nonsense you like if you can delude yourself into thinking that you have applied scientific reasoning to the problem.

Anyway, that was my take on it. I did not see where this was a blind, or better a double-blind test, perhaps holding stones inside a blind-box, or even as simple as behind one’s back.