Abstract

Introduction: Delay discounting (DD) means prefering small immediate rewards to large delayed rewards. This study was to assess delay discounting and the correlation of our findings with that of the Zimbardo Time Perspective Inventory (ZTPI).

Method: In a cross-sectional study, DD and time perspective were investigated in 93 medical interns by means of a computer software and ZTPI. In delay discounting procedure (DDP), sub- jects chose between hypothetical monetary rewards available immediately or delayed 6 hours to 25 years. ZTPI consists of 56 items in five subscales. A nonlinear curve fitting program, t test, Mann-Whitney U Test and Pearson correlation were used for data analysis.

Results: Hyperbolic function had good fitness to the results of delay discounting procedure (DDP). On ZTPI, the positive future and positive past subscales showed highest means the lowest mean was of the present fatalistic.  No meaningful correlation was found between DDP and ZTPI. Also, there was no significant difference between male and female participants.

Conclusion:The delay discounting procedure based on a hyperbolic model has application for measurement of impulsivity in an Iranian sample. Absence of any meaningful correlation between DDP and ZTPI suggests that probably the tests relate to distinct aspects of impulsivity.