The Psychology of Queues

In 1988, a Harvard Business School professor named David Maister published a paper titled “The Psychology of Waiting Lines” that contains what is probably the most practically useful set of observations about daily life that management research has ever produced. Maister was not particularly interested in cutting queues. He was interested in something subtler: the experience of waiting, which he argued is almost entirely separable from the objective duration of waiting. His core insight was that unoccupied time feels longer than occupied time, and that this is not a cognitive error but a feature of how attention and memory work. A five-minute wait while reading a magazine registers as shorter than a two-minute wait staring at a blank wall.

The implications of this observation, which sounds obvious in retrospect, were profound. If the subjective experience of waiting is determined largely by what occupants are doing and thinking rather than by actual elapsed time, then the problem of waiting is not primarily an operations research problem (how do we serve more customers faster?) but a psychology problem (how do we make waiting feel less unpleasant?). These are different problems with different solutions, and for most of the history of queuing, organizations have been solving the wrong one.

The elevator industry discovered this independently sometime in the 1950s. Complaints about slow elevators in New York office buildings were generating significant tenant dissatisfaction. Building managers pressured landlords to upgrade elevator banks, which was expensive. An engineer at Otis Elevator Company, the story goes, suggested that the complaints might be about perceived slowness rather than actual slowness, and proposed installing mirrors in elevator lobbies. People waiting for elevators would look at themselves, look at other people, check their appearance. Time would pass without feeling wasted. The complaints dropped substantially. The mirrors cost almost nothing. This is probably the most cited example in the waiting-psychology literature, and it is worth noting that it probably happened slightly differently than the legend suggests — the attribution to Otis is disputed — but the underlying phenomenon is well documented in controlled studies.

What Maister identified as the seven propositions of waiting psychology have held up remarkably well across forty years of subsequent research. Unoccupied time feels longer. Pre-process waits feel longer than in-process waits. Anxiety makes waits feel longer. Uncertain waits feel longer than certain ones. Unexplained waits feel longer than explained ones. Unfair waits feel longer than fair ones. Solo waiting feels longer than group waiting. Each of these propositions has implications for design, and taken together they suggest that the designers of waiting experiences — whether in hospitals, theme parks, restaurants, or government offices — have an extraordinary amount of latitude to shape how waiting feels without changing how long it actually takes.

Disney understood this before almost anyone else. The queuing experience at Disney theme parks is deliberately engineered to minimize the subjective experience of waiting. Lines curve so that guests cannot see how long the line actually is (uncertain waits feel longer; paradoxically, Disney conceals the queue length to prevent guests from accurately calculating their wait). Lines incorporate “pre-show” elements — videos, props, interactive displays — that turn the wait into part of the attraction. FastPass and its successors provide a way to convert idle waiting time into active time elsewhere in the park. The posted wait times are systematically inflated: if the sign says 40 minutes and guests actually wait 35, they feel the pleasant surprise of beating the estimate; if the sign says 30 and they wait 35, they feel cheated. This is a known and deliberate strategy.

The contrast with most hospital waiting rooms is instructive. A typical emergency room waiting room in the United States provides uncomfortable chairs, television sets tuned to news channels (often covering distressing stories), and minimal information about where a patient is in the queue or how long they might wait. All of these violate every principle of waiting psychology simultaneously. The wait is unoccupied (television does not count as occupation in the psychologically meaningful sense), uncertain (patients typically have no idea when they will be seen), unexplained (triage logic is invisible), and anxiety-producing (the health system that is making you wait is the same system you are depending on to address a health problem that already has you frightened). Hospitals have known about waiting psychology research for decades and have mostly failed to act on it.

The disparity between Disney’s queue design and hospital queue design is not primarily a function of resources or technical knowledge. It is a function of competitive pressure and organizational attention. Disney has extraordinarily strong financial incentives to optimize the guest experience, including the waiting experience: unhappy guests don’t return, don’t recommend the park, and don’t spend money at concessions while they’re miserable. Hospitals face weaker competitive pressure and have historically directed organizational attention toward clinical outcomes rather than patient experience — a reasonable priority ordering in itself, but one that treated waiting as an irreducible cost rather than a designable experience.

The academic field most closely connected to these questions is actually operations research, which studies queuing theory mathematically. Queuing theory was invented by Agner Krarup Erlang, a Danish mathematician who in 1909 published the first rigorous analysis of telephone exchange traffic. Erlang was interested in how many telephone circuits were needed to handle calls with acceptable probability that no caller would get a busy signal. His equations are still the foundation of traffic engineering, call center staffing, and any other domain where a flow of customers arrives stochastically and waits to be served by a limited number of servers.

Erlang’s mathematics are impeccable, but they are indifferent to psychology. Queuing theory can tell you the optimal number of bank tellers to minimize average wait time given a predicted arrival rate. It cannot tell you whether a bank should use a single serpentine queue feeding multiple tellers (which is fairer and feels slightly faster) or multiple parallel queues (which gives customers a sense of agency but generates the infuriating experience of watching adjacent queues move faster). The psychology literature strongly favors the serpentine queue, and banks have mostly adopted it, but the adoption took decades and the last holdouts only converted in the 1990s.

The fairness proposition from Maister’s list deserves particular attention because it connects to the deepest levels of human social psychology. People are extraordinarily sensitive to queue-jumping, and the reaction to it is disproportionate to any objective harm. A 2009 study by researchers at Stanford asked participants to report their emotional response to queue-jumping in various contexts. The anger response was roughly as intense whether the queue-jumper cut ahead of the participant or ahead of a stranger the participant had never met. This suggests the reaction is not primarily about the personal cost of additional waiting time but about the violation of a norm — the sense that an implicit social contract has been broken.

This is why the “express lane” model at theme parks, airports, and various services is so psychologically delicate. Premium queue access, where wealthy customers pay to skip lines that other customers wait in, is objectively a queue-jump that participants have agreed to and presumably accepted as legitimate. But it still generates resentment in the regular-queue holders, because the fairness norm operates intuitively rather than rationally. The fact that you knew the express lane existed when you bought your ticket does not prevent you from feeling mildly aggrieved when someone breezes past you. Disney handles this partly through physical design — FastPass users rejoin the queue at a point that regular guests never see — which reduces the salience of the jump without eliminating it.

The most interesting recent development in waiting psychology is the research on post-experience evaluation. Psychological research consistently shows that people’s memories of an experience are shaped disproportionately by the peak moment (best or worst) and the ending (the “peak-end rule,” identified by Daniel Kahneman and his colleagues in the 1990s). This means that a waiting experience that ends well is remembered as better than one that ends badly, even if the total wait time is identical. Hospitals that have adopted the practice of sending a nurse to the waiting room to give waiting patients a brief update and timeline estimate — a low-cost intervention that takes about 90 seconds — report substantially higher patient satisfaction scores, not because the wait is shorter but because the encounter creates a positive peak and a more optimistic frame for the ending.

What all of this research converges on is a fairly radical conclusion: the relationship between objective service quality and subjective satisfaction is much weaker than most organizations assume. You can reduce average wait times by 20 percent through expensive operational improvements and produce a smaller satisfaction gain than a well-designed lobby, a reliable progress indicator, or a staff member who takes 90 seconds to acknowledge that someone is waiting. This is not an argument against operational improvements. It is an argument that organizations systematically underinvest in the psychology of service delivery while overinvesting in the engineering of it.

Maister published his original paper in a course note for MBA students. It was never peer-reviewed in the conventional sense, and its seven propositions are derived from observation and reasoning rather than formal experiments. Subsequent research has tested and largely validated them, but the original paper works because it captures something real about human experience that most organizations had systematically ignored. The measure of a useful insight is not how novel it sounds but how much it changes what people do after they hear it. By that measure, the psychology of waiting lines is one of the more productive intellectual contributions of the past half century — even if most hospitals still haven’t read it.