Because the trip there was so disappointingly long.
We’ve all felt it before: for whatever reason, the trip coming home seemed a lot quicker than the trip going there. This isn’t just you losing your already tenuous grip on reality; on the contrary, several studies have confirmed the existence of what researchers call the “return trip effect.” Even when travel distance and time are the same there and back, the back feels measurably shorter.
Exactly why this effect occurs is a source of ongoing inquiry. Eryn Brown at the L.A. Times reports on a new study in PLOS One offering one potential explanation: it’s not that we’re bad at judging how long a trip is taking, it’s that we’re bad at remembering how long it took. That’s what the researchers found when asking study participants to watch a video of a round-trip then asking them to judge its length in real-time and retrospectively.
The study does support the basic “return trip effect,” but its methods and reasoning are unconvincing. The sample size was woefully small, at 20 participants. The researchers assumed we have to travel the exact same route there and back to feel the effect, which isn’t necessarily true. And their conclusion was flat: even if people recall return trips poorly, the question of why they have this particular memory failure still remains.
Two theories: familiarity versus expectation
For a stronger theory on the “return trip effect” we (re)turn to a clever series of studies reported in a 2011 paper in the Psychonomic Bulletin & Review. The work was led by social psychologist Niels van de Ven of the Tilburg University in the Netherlands.
Ven and collaborators wanted to explore two possible explanations for the “return trip effect.” One was “familiarity”: just as routine tasks seem to take less effort than new ones, perhaps familiar routes seem to take less time to complete. The other was “expectations”: if the way there takes longer than we thought it would, then perhaps we adjust our time expectations upward on the way back, and find ourselves pleasantly surprised when it doesn’t take as long.
For the first study, the researchers intercepted 69 people who’d just returned from a bus trip to and from a fair or a theme park. (They limited their focus to groups whose trips took the same amount of time there and back.) Sure enough, everyone showed a return trip effect, saying the trip home had been shorter. But these responses weren’t related to route familiarity, as measured by how many waypoints they’d recognized coming home. The effect did, however, seem related to expectation: travelers who felt the initial trip took longer than expected showed a stronger feeling that the return trip had been quicker.
For a second study, the researchers put a tighter clamp on the variables. They spoke with 93 participants who’d just taken a there-and-back bike trip. All the legs took the same amount of time (35 minutes) but some of the participants went there and back the same route while others took a different route back. Once again, everyone showed a “return trip effect,” with the way back estimated to take 37 minutes on average, and the way there 44 minutes.
The different route options helped the researchers study the familiarity theory more closely. If familiarity theory were correct, the participants who rode their bike back the same way should have shown a stronger “return trip effect”—thinking the trip significantly quicker than those who rode back a new way. In fact, no such difference occurred. But the researchers did find more evidence for the expectation theory: those who felt the initial trip took longer than expected also felt the return trip was shorter.
A final study, totally controlled in a lab, sealed the deal. This time 139 test participants watched video of someone riding a bike to and from a friend’s house. All legs of the trip took exactly 7 minutes, though sometimes the rider took an alternate route back.
Once again, the “return trip effect” reared its head: overall, participants estimated the trip there to take a little over 9 minutes, against a little over 7 minutes for the trip back. And once again, familiarity didn’t seem to play a role; return trip estimates were no different regardless of which route the bike rider took. And once again, expectations seemed to matter most—most notably, when the researchers led some participants to think the initial trip would take longer, the return effect disappeared.
The effect is “likely due to a violation of expectations”
The third experiment, in particular, strongly suggests that when people are no longer disappointed with the trip there, they take a more accurate accounting of the trip back. Ven and company don’t completely dismiss a familiarity component to the “return trip effect,” but they do think expectations play more of a role. They conclude:
Instead, the return trip effect is likely due to a violation of expectations. Participants felt that the initial trip took longer than they had expected. In response, they likely lengthened their expectations for the return trip. In comparison with this longer expected duration, the return trip felt short.
It’s quite possible several factors are at work here. Perhaps we do overestimate the initial trip and therefore feel better about the trip home. Then our flawed memories might remember the first trip as being even worse than it truly was once we get back. Then familiarity with a given route might help us perpetuate the “return trip effect” on a regular basis.
Future studies should also look at the role of emotions on our return trip perceptions. Maybe the stress of returning to work makes a trip home from vacation seem longer; then again, maybe the mental distraction of preparing for the work week makes that same trip feel shorter. A study that separated business and leisure travel might offer new insights. What we’re doing on the trip no doubt also plays a role, and ditto for the people we’re traveling with.
Here’s hoping the science speeds up and gets there already.