The Scientific Difference Between a Yuppie and a Hippie

What's the difference between a yuppie and a hippie? Science to the rescue! Psychologists Mark Pezzo, Jordan Litman and Stephanie Pezzo discovered that yuppies and hippes are quite different in their tendency to underestimate task-completion times (aka planning fallacy):

The present study investigated variables related to errors in predicting when tasks will be completed. Participants (N = 184) responded to the Time Structure Questionnaire (TSQ; Jones, Banicky, Pomare, & Lasane, 1999) and Temporal Orientation Scale (TOS; Bond & Feather, 1988) and predicted when they would complete either a desirable or undesirable task. Factor analysis of the TSQ and TOS identified two factors: yuppie traits, which involved being hard-working and goal-oriented, and hippie traits that reflected “living for the moment”. Overall, individuals tended to underestimate when they would complete both tasks. However, for the undesirable task, yuppie traits corresponded with less prediction bias whereas hippie traits were associated with greater bias.

Translation: yuppies are better at estimating how long it would take them to complete an undesirable task, whereas hippies are not so swift at it.