Ever wonder why getting to your destination seems to take forever, but the return trip passes in a flash? Japanese researchers this week shed light on the phenomenon. Writing in PLOS One, the team notes that "studies on the return trip effect have failed to confirm its existence in a situation that is ecologically valid in terms of environment and duration." So they dug into the "return trip effect" by asking 20 men, ages 20 to 30, to watch two point-of-view movies, about 26 minutes long, featuring either an outbound and return walking trip, or two one-way walking trips on city streets. The men had to verbally state each time they thought a three-minute interval had passed; afterward, they were asked to rate the films' length on an 11-point scale, with -5 indicating the first was a lot longer, and +5 indicating the second was far lengthier.
Participants didn't experience the trips any differently during the films. Afterward, however, those who'd witnessed the round-trips "consistently" found the return leg to be shorter, Vox reports. "The return trip effect is not a matter of measuring time itself. Rather, it depends on time judgment based on memory," Ryosuke Ozawa tells the Los Angeles Times. Vox points to research that shows our brains track the passage of time using two systems, one mathematical and one language-based, with the latter creating "stories" about the timing of events we've experienced. As Vox puts it, "It appears this second system was the one fooled by the return trip effect." The researchers echo this, writing the results indicate "that the return trip effect does not affect the timing mechanism itself, but rather our feeling of time postdictively." (When it comes to walking, how you do it can change your mood.)