Many decisions are about unknown quantities. How far is it from A to B? Is the price good? How much time do I need for this task? A series of experiments with more than 6400 participants shows: with such questions you can help yourself with a trick and ask for advice in your mind from a person who usually has a different opinion.
The test subjects, recruited via online research platforms in the USA and Great Britain, should estimate how much a washing machine, a piano or an elephant baby weighs. Then they were asked to think again, but in different ways: some should simply advise you a second time, the others take the perspective of a friend who thinks in terms of politics. And a third group should imagine a friend who often represents other political views: what would he say?
In the third group, the second tip differed more clearly from the first than in the other two groups. And that was exactly what turned out to be an advantage: the middle between the two tips of the third group came closest to the right result. Forming the average between the two tips was not only better than the first tip, but also better than the middle between the first and second tips from the other two groups. The real value was only in around every fifth case between the two estimates - on the other hand, in every third case if the fictional opinion of a friend that thinks was involved was included.
The wisdom of the Many
The two researchers Philippe van de Calseyde from the TU Eindhoven and Emir Efendic from the University of Maastricht speak of a "Inner Crowd Effect", based on "Wisdom of the Crowd", the wisdom of the many. The latter is the often confirmed phenomenon that the average of many independent estimates usually get a true value closer than individual opinions. But apparently no real survey is needed among many: it helps to imagine a different opinion and to adapt your own judgment accordingly - because then the second tip differently differentiates from the first, as the authors explain.
In certain cases, however, this can also be a disadvantage: when it comes to numbers at the edges of a scale. For example, when it comes to the question of what proportion of the population in China adheres to Christianity (about five percent): in low or high percentages, a second tip, which deviates significantly from the first, tends to lead away from the correct result.
