Next time you are in China, take some elevator rides in a wide variety of buildings and use a stopwatch or something with sweep second hand to time the lags. By the end of your stay in China, you'll be pushing emphatically on that "door close" button also.[/QUOTE]

Made a recent study. Close time seemed actually rather short. Avg ~2 seconds.
However found it common that close button is always used as if its a requirement.
More like a conditioned act.

Sampling 12 buildings from 20 to +100 floors.