Take a look at the leftmost bar. Does its length match line A, B, or C on the right card? It doesn’t take a neurosurgeon to see that it matches line C. In fact, only one in thirty-five people get this question wrong when asked individually.
But 36.8 percent of Solomon Asch’s test subjects answered the question incorrectly.
Why? They were duped by da group: Alongside ringers who were instructed to pick line A or B, test subjects switched their opinions to match those of the group.
Variations of the experiment found that it takes three or more people voicing a unanimous opinion to make a subject go along with an obviously incorrect choice. And if even one other member in a large group dissents, it frees the subject to dissent too, even if the first dissenter expresses an incorrect opinion.
Genius Tester #5: Mr. Smith’s Children
In 1959, science writer Martin Gardner published the following puzzle in Scientific American:
Mr. Jones has two children, the eldest of whom is a girl. What’s the probability that both children are girls?
Mr. Smith has two children, at least one of whom is a boy. What’s the probability that both children are boys?
Check the solution. It’s as good as the puzzle.
