In an experiment a few years ago, students posing as beggars found that they received small change 44% of the time that they asked directly for it without specifying a sum. If they asked for a precise sum that was a single coin (25 cents), they got it 64% of the time. But if they asked for an apparently arbitrary number (37 cents) they got it 75% of the time. The more precise and unusual the request, the less people were able to resist it.