Hindsight bias

The hindsight bias, although it was not yet named, was not a new concept when it emerged in psychological research in the 1970s. In fact, it had been indirectly described numerous times by historians, philosophers, and physicians. In 1973, Baruch Fischhoff attended a seminar where Paul E. Meehl stated an observation that clinicians often overestimate their ability to have foreseen the outcome of a particular case, as they claim to have known it all along. Baruch, a psychology graduate student at the time, saw an opportunity in psychological research to explain these observations. In the early seventies, investigation of heuristics and biases was a large area of study in psychology, led by Amos Tversky and Daniel Kahneman. Two heuristics identified by Tversky and Kahneman were of immediate importance in the development of the hindsight bias; these were the availability heuristic and the representativeness heuristic. In an elaboration of these heuristics, Beyth and Fischhoff devised the first experiment directly testing the hindsight bias. They asked participants to judge the likelihood of several outcomes of US president Richard Nixon's upcoming visit to Beijing (then romanized as Peking) and Moscow. Some time after president Nixon's return, participants were asked to recall (or reconstruct) the probabilities they had assigned to each possible outcome, and their perceptions of likelihood of each outcome was greater or overestimated for events that actually had occurred. This study is frequently referred to in definitions of the hindsight bias, and the title of the paper, 'I knew it would happen', may have contributed to the hindsight bias being interchangeable with the phrase 'knew it all along' hypothesis. In 1975, Fischhoff developed another method for investigating the hindsight bias, which at the time was referred to as the 'creeping determinism hypothesis'. This method involves giving participants a short story with four possible outcomes, one of which they are told is true, and are then asked to assign the likelihood of each particular outcome. Participants frequently assign a higher likelihood of occurrence to whichever outcome they have been told is true. Remaining relatively unmodified, this method is still used in psychological and behavioural experiments investigating aspects of the hindsight bias. Having evolved from the heuristics of Tversky and Kahneman into the creeping determinism hypothesis and finally into the hindsight bias as we now know it, the concept has many practical applications and is still at the forefront of research today. Recent studies involving the hindsight bias have investigated the effect age has on the bias, how hindsight may impact interference and confusion, and how it may affect banking and investment strategies. Hindsight bias has been found to be greater, or to be more likely to occur, when the outcome of an event is negative than positive, a phenomenon consistent with the more general tendency for people to pay more attention to negative outcomes of events than positive ones. In addition, hindsight bias is affected by the severity of the negative outcome. In malpractice suits, it has been found that the more severe the negative outcome the more dramatic the jurors' hindsight bias. In a perfectly objective case, the verdict would be based on the physician's standard of care instead of the outcome of the treatment; however, studies show that cases that end in severe negative outcomes such as death result in higher levels of hindsight bias. For example, in 1996, LaBine proposed a scenario where a psychiatric patient told a therapist that he was contemplating harming another individual. The therapist did not warn the other individual of the possible danger. Participants were each given one of three possible outcomes; the threatened individual either received no injuries, minor injuries, or serious injuries. Participants were then asked to determine if the doctor should be considered negligent. Participants in the 'serious injuries' condition were not only more likely to rate the therapist as negligent but also rated the attack as more foreseeable. Participants in the no injuries and minor injury categories were more likely to see the therapist's actions as reasonable.