Telling it like it is

VINGT-ET-UN, known to Americans as blackjack, is a card game in which players must decide whether the value of the two-card hand they are dealt is likely to be enough to beat the dealer’s unseen hand, or whether they should risk going bust by adding to it, one card at a time, as they seek to get as close as possible to a permitted maximum of 21 points. (Court cards are worth ten; aces score either one or 11, at the holder’s discretion.)

Making constant calculations is thus an essential part of this game—a fact that Kevin Holmes, a psychologist at Colorado College, in Colorado Springs, has used to test his hypothesis that such calculation will cause players to give away, by their eye movements, the sorts of hand they have. As he reports in Psychonomic Bulletin and Review, it turns out that they do.

Dr Holmes knew from studies by others that when people are asked to perform a mental calculation and then to point to the location of the answer on an unmarked horizontal line (known as a number line) whose left-hand end represents a numerical value, such as zero, and whose right-hand end represents a larger one,…Continue reading
Source: Economist