Time seems to accelerate with increasing age. This subjective acceleration or compression may be due to the operation of a linear or a square-root function that relates present age to past age. A subjective magnitude-estimation technique was applied in a questionnaire given to 282 university students to determine which function best fitted the data. The results did not support the hypothesis that subjective time is estimated by either linear or square-root functions. Instead, the results indicate that subjective time is estimated with respect to a stable constant independent of age. These results support the notion that the purely subjective perception of time may serve as a measure of psychological temporal processes that remain stable with age. A linear function of age was, however, significantly related to error in the estimation of test-duration.

282 undergraduate students between 17 and 68 years of age were asked to list the 5 most significant experiences of their lives, to assign the time zones to these experiences, and to provide estimates of emotional valence corresponding to each significant life experience they listed. Subjects also provided judgements of time perspective on a Life Line. The sample showed a near-past orientation and a positive emotional valence across the experiences reported. However, the first experiences reported were distant past experiences significantly more frequently than expected by chance, while the last experiences in the Experiential Inventory were significantly more often located in the distant future. While this result validates the prevailing assumption of a unidirectional flow of past to future, empirical evidence was also found for the larger magnitude and variability of future as compared with past perspective. This suggests a bidirectional model of time should be invoked to explain the differing character of the opponent temporal processes of recall and anticipation in human experience.

282 undergraduate students between 17 and 68 years of age were asked to list the 5 most significant experiences of their lives, to assign the time zones to these experiences, and to provide estimates of emotional valence corresponding to each significant life experience they listed. Subjects also provided judgements of time perspective on a Life Line. The sample showed a near-past orientation and a positive emotional valence across the experiences reported. However, the first experiences reported were distant past experiences significantly more frequently than expected by chance, while the last experiences in the Experiential Inventory were significantly more often located in the distant future. While this result validates the prevailing assumption of a unidirectional flow of past to future, empirical evidence was also found for the larger magnitude and variability of future as compared with past perspective. This suggests a bidirectional model of time should be invoked to explain the differing character of the opponent temporal processes of recall and anticipation in human experience.