When we travel, why does the return always seem shorter than the outward journey?
No, the road hasn't suddenly shortened. Nevertheless, according to several studies, there is indeed a “round-trip effect”.
A 2015 study published in PLOS ONE (a scientific megareview) reveals that this sensation linked to the length of a journey is the result of our inability to remember the length of an outward journey, i.e. the length of time initially experienced. Based on a sample of just 20 people, this study should be treated with caution.
In another study, from 2011, published in Psychonomic Bulletin & Review, researchers look at two possible reasons for this “round-trip effect”: expectations and familiarity. In the latter case, the sensation of shorter duration is due to the fact that the journey has already been experienced once, and that we're therefore used to it. In the case of “expectations”, if the outward journey takes longer than expected (because we tend to misjudge the number of hours involved), we adjust our expectations for the duration of the return journey, says Belgian media RTBF. And it's a surprise when the return journey is shorter than “expected”.
The researchers conclude: “The effect of the return trip is probably due to a violation of expectations. Participants felt that the initial trip had taken longer than expected. In response, they probably lengthened their expectations for the return trip. Compared with this longer expected duration, the return trip seemed short to them.”
(MH with AsD - Source: RTBF - Illustration: Unsplash)