Are you a fan of Balsamic vinegar in your beer? Perhaps you would be if you didn’t know it was there. “Predictably Irrational” is a new book by  Duke University professor Dan Ariely that explains the ways in which our expectations can hugely affect our experiences and decisions. A study he performed at M.I.T. approached almost 400 pub patrons and asked them to sample two beers. One was  regular Budweiser while the other was Budweiser with a few drops of Balsamic added. Participants were either never told about the vinegar, told before tasting or told after tasting. Those that were never told or told only after tasting the two beers much preferred the “Special Blend” to the regular beer, while those told before tasting did not.

The conclusion was that it is the expectation that the beer would taste bad and not the actual information about the extra ingredient that made the difference. Arly points out in the study that this expectation aversion and the benefits of remaining ignorant is routinely, and correctly, exploited by mothers trying to get their children to try new foods. Mothers also seem to recognize the second part of the equation, that the deception need not be upheld after a positive reaction has been obtained. In other words once the stubborn child has happily consumed the new food safe in the knowledge that there was nothing “Yucky” in the portion mothers then smugly inform them of the reality knowing that it now makes no difference.

Curiously though the study found that although the above situation is common in households the fact that the new found preference for the new food persists even after being told the distasteful truth was not intuitive and could not be predicted by M.I.T. students surveyed. If asked how many people would still prefer the vinegar infused beer after being told the truth the students were all over the map in their predictions. So the “Try It, You’ll Like It” gambit used by parents everywhere really does work, but only if you withhold the truth first.