Here's why trip back home feels shorter in hindsight

A new study has revealed that people reflecting on a roundtrip walk estimated that the return trip took less time than the outward trip.

Many have experienced the "return trip effect," where the return trip seems shorter than the outward trip, even when the trips actually took the same amount of time.

Ryosuke Ozawa from Kyoto University and colleagues compared a group of 20 men watching two of three prerecorded walking movies, of either an outbound trip and a return trip or two outbound trips. The participants estimated the length of the two movies both while watching and then again after the two trips.

Only the participants from the group watching an outbound trip and a return trip-a roundtrip-estimated that the second trip took less time than the first trip.

Furthermore, the participants felt the return trip effect only when reflecting on length after the trips.

By comparing the round-trip condition and the non-round-trip condition, the authors suggest that the return trip on a roundtrip may actually make us feel that time is shorter even without walking, and that the return trip effect may not affect the timing mechanism itself, but rather our feeling of time retrospectively.

Further research is needed to better understand the contribution of the awareness of "return," since the labeling such as "roundtrip" or "return" may be another factor in inducing the cognitive bias of the return trip effect.

The study is published in the open-access journal PLOS ONE.