Biases in thinking
Labour illusion
Also called Labor illusion
People value a result more when they can see the work that went into it, even if it means waiting a little longer.
A search that shows it checking hundreds of sources feels more thorough than one that returns the same results instantly with no explanation.
Showing what's happening during a wait builds trust and makes the result feel earned. It only works if the work is real and the wait is reasonable.
In practice
A travel site that lists the airlines it's checking while it searches tends to be rated more highly than one that shows a plain spinner for the same time.
Common mistake
Adding fake delays and fake progress to look busy. It's deception, and people who spot it feel manipulated.
Where it comes from
Described by Ryan Buell and Michael Norton of Harvard Business School in 2011, from experiments with travel and dating search sites.