On Once and Future Things: A Temporal Asymmetry in Judgments of Likelihood

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What do people see when they gaze into the future? Many people, at least among those in Western cultures, see a future brimming with possibilities. The past, on the other hand, is rarely described as being full of possibility. This is not surprising, as the future is associated with a greater number of possible outcomes, is unknown, and is potentially changeable, whereas the past is associated with fewer possible outcomes, is known or potentially knowable, and cannot be changed. In this dissertation, I argue that because people associate the future with openness and possibility more so than the past, they tend to see any particular uncertain event as more probable in the future than in the past, all else being equal. That is, people judge focal future events to be more likely than otherwise identical past events, once differences in knowledge of the past and future are eliminated. I report a series of studies aimed at documenting this phenomenon and testing the proposed mechanism, the tendency to associate the future with openness and possibility. In Chapter Two, I describe three studies demonstrating this past-future asymmetry in likelihood judgments and testing some of the parameters of this phenomenon. In Chapter Three, I report the results of three studies that provide support for the hypothesized cause of this effect, the association between the future and possibility. In Chapter Four, I describe two studies examining some extensions of this effect beyond the realm of likelihood judgments. Finally, in Chapter Five I discuss some implications and boundary conditions of this effect, and outline future directions for this work.

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Subjective Likelihood; Time; Future; Prediction; Postdiction


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