[mockingbirdy]

Don't underestimate the power of subconscious processes, e.g. we like things we already know or even words that contain letters of our name [1]. There exists an incredible amount of these biases.

> There are a million guarantees that what is being done is thoroughly and totally meaningless.

There are a million subtle ways to influence behavior and thinking. It's very likely that the scientists aren't able to properly measure the effects (because it's hard to isolate the control variables), but the resulting knowledge won't be zero. I agree with you that many scientists overestimate their understanding of the underlying mechanisms - IMO it's still too much hand-waving - in reality our knowledge about social psychology is very limited.

[1]: https://en.wikipedia.org/wiki/Mere-exposure_effect