> Psychological experiments involve trickery very often, because they need test subjects to be unaware of what experiments is trying to measure. I expect the mo

> Psychological experiments involve trickery very often, because they need test subjects to be unaware of what experiments is trying to measure. I expect the most of subjects of psychological experiments to know this because they heard of other experiments. So I wouldn't expect that the trust building will change anything. Long time ago, the joke was that "subjects are 19-23 years old women studying psychology and who happened to walk in the faculty halls that day".