It looks like the least efficient way to clear a table.<\/p>\n
One mug, one trip, back and forth, when waiting five more minutes would let the same person carry all four at once and cut the total number of trips by three quarters.<\/p>\n
Efficiency experts would wince. And yet almost everyone has done exactly this, at some point, without being able to explain why beyond a vague sense that it just felt better to get it out of the way.<\/p>\n
Psychology has spent the last decade building a fairly precise account of what that feeling actually is, and it has nothing to do with tidiness or impatience.<\/p>\n
The bucket experiment that started it<\/p>\n
The pattern was first documented in a 2014 study by the psychologist David Rosenbaum and his colleagues Lanyun Gong and Cory Adam Potts, published in Psychological Science<\/a>. Participants walked down an alley toward a platform at the far end, with one bucket sitting near the start of the walk and an identical bucket sitting much closer to the platform. Told to pick up either bucket and carry it the rest of the way, most people grabbed the nearer one \u2014 the one requiring them to carry it for a much longer stretch of the walk \u2014 rather than the farther bucket, which would have meant far less total carrying distance.<\/p>\n This held even when the buckets were heavy enough that carrying one for longer clearly cost more physical effort, and even when participants had already lifted both buckets beforehand and knew exactly how much that extra effort would be. Rosenbaum coined a name for the behavior: precrastination, the opposite impulse to procrastination, the urge to get a subtask done as early as possible even at a real physical cost.<\/p>\n What the effort is actually buying<\/p>\n The explanation that has held up best since then is what researchers call the cognitive-load-reduction hypothesis, tested directly in a 2018 follow-up by Lisa Fournier and colleagues, published in Attention, Perception, & Psychophysics<\/a>. The idea is straightforward once it\u2019s spelled out: an unfinished task, even a trivial one like \u201cremember to carry that other bucket eventually,\u201d takes up a small amount of working memory for as long as it stays unfinished. Finishing it early clears that mental slot immediately. People in the study were, in effect, trading physical effort they\u2019d feel in their arms for mental effort they wouldn\u2019t have to keep paying rent on. Given that trade, plenty of people take it, every time, often without noticing they\u2019re making a decision at all.<\/p>\n Two hundred million years of the same trade<\/p>\n In 2015, the psychologist Edward Wasserman ran a version of the bucket problem on pigeons, reasoning that if precrastination reflects something as basic as cognitive-load reduction, it shouldn\u2019t be limited to species that carry groceries. Pigeons pecked a touchscreen through a three-step sequence to earn food, choosing between a path that deferred a location switch and one that got it out of the way early. The birds precrastinated almost every time<\/a>, resolving the switch as soon as the option appeared rather than waiting.<\/p>\n The finding didn\u2019t stay uncontested. A later team led by Thomas Zentall ran a version of the task structured more like Rosenbaum\u2019s original alley walk than Wasserman\u2019s touchscreen sequence, and got the opposite result: the pigeons procrastinated. Their argument was that Wasserman\u2019s setup may have rewarded early switching for a more mundane reason \u2014 a conditioned association between the early cue and the payoff \u2014 rather than anything resembling a pigeon clearing a mental to-do list. Whether pigeons are actually managing something like working memory here, or just responding to reinforcement timing, is still an open question between the two labs.<\/p>\n What isn\u2019t in dispute is that the underlying trade-off \u2014 pay a cost now to close out a pending outcome sooner \u2014 shows up in a species whose evolutionary line split from ours roughly 300 million years ago. Whatever precrastination turns out to be at the mechanistic level, it isn\u2019t obviously a product of modern, overscheduled human life.<\/p>\n Where the mug fits<\/p>\n The single-mug trip runs on the same logic, even though nobody ran a controlled study on kitchen tables specifically. Waiting to carry four mugs at once means holding \u201cstill need to deal with those mugs\u201d as an open loop for however long the wait lasts \u2014 a small, low-grade mental tab that has to stay open until the job gets done. Carrying one mug immediately closes that loop the instant it\u2019s picked up, at the cost of making three more trips later. The physical cost is obvious and easy to price: three extra walks to the kitchen. The mental cost being avoided is much harder to see, precisely because avoiding it is what makes the open loop disappear before anyone has to notice how much it was quietly costing them.<\/p>\n Not a personality trait, a trade-off<\/p>\n None of this means every one-item trip is secretly optimal, and prolific precrastinators aren\u2019t quietly winning some efficiency contest the rest of us are losing. Four trips is still four trips, and there are plenty of situations where waiting really is the better call. What the research does clarify is that the impulse isn\u2019t a character flaw or a tic worth correcting. It\u2019s a legible, fairly universal trade a mind makes constantly, choosing to spend a bit more of the body\u2019s effort in exchange for a bit less of the mind\u2019s, and mostly making that trade without ever putting it into words.<\/p>\n The grocery-bag version got tested directly<\/p>\n