Oddly Wired
← all facts
perception

Wait times seem longer when you are uncertain.

The uncertainty effect in waiting demonstrates that people perceive wait times as significantly longer when the end of the wait is unknown.

A queue with no end in sight triggers more anxiety and negative evaluation than a queue where the end is visible or estimated. Providing information about the duration—even if that duration is long—mitigates the subjective sense of lost time. The brain processes known durations differently than ambiguous ones.

The frustration you feel in line is rarely about the time itself.

Where this comes from

Study
Carmon and Kahneman, 1996, Journal of Consumer Research
What the check found
The referenced study (Carmon and Kahneman, 1996, JCR) accurately discusses how uncertainty and lack of information exacerbate negative evaluations of wait times, though the terminology used here is slightly imprecise.
Confidence
Solid, with limits

Related

One of these every day, and every one names the study it came from. When a finding is contested, it says so.