All right. That is a very good question to bring up. Rules like those described are not as straightforward to understand to ordinary people as they may seem to the experimenter. I had to read it a couple times to understand that the idea was to tell the truth if 2-5, and give a fixed response if 1 or 6. Surely there were participants that didn't understand and the number among rural farmers is going to be different than the number among western college psychology students upon whom most of these sorts of tests are developed and calibrated. 6 is an unlucky number, the number of the devil in some cultures. Other cultures have feelings about 1 (unity), 2 (dualism), 3 (trinity), 4 (chinese good luck, indian sacred number) and 5 (witchcraft). When talking of small effects, there may be emotions experienced that vary from person to person depending on their education, IQ, cultural background and environment. This can skew results in a way that is dependent on the particular population tested. A person from a culture that believes that 6 is an evil number and a bad omen may be very slightly more likely to change their response on a 6, seeing it as a warning. One can't take a test like this that is quite subtle and looks at tiny effects within noise signals that come not from rocket engines but from subjective human reactions and dump it on any population and assume results calibrated on a different population are a valid interpretation. That would have to be shown first, in cross-cultural comparison testing.