How statistically significant is it that Dr. Gottman can predict divorce with such a high rate of accuracy?
Dr. Gottman’s ability to predict divorce among newlyweds is more clearly understood by imagining an urn that contains 130 white balls (representing couples that stayed married) and 17 red balls (representing couples that ended up divorcing) for a total of 147 balls. The chances that Dr. Gottman could blindly pick balls out of the urn and guess which were red and which were white with 90% accuracy could only happen by chance 1 x 10-19 times. That is the number point one (0.1) with 18 zeroes in front of the number one. This means it is practically impossible that Dr. Gottman could predict which couples would divorce with much accuracy by chance alone. The factors he used to make his predictions were indeed clearly related to why couples ended up divorced. By looking for those factors, he was able to predict divorce fairly accurately. For the Gottman, Katz and Hooven study, where Gottman et. al. picked out all seven divorced couples out of 56, the probability is approximately .00000000038
