https://www.theatlantic.com/magazine/archive/2017/09/how-to-cut-in-line/534222/
This source is rather old (1976, same as me!) but useful as it has sections on arousal, overload and behavioural constraint with reference to both crowding and personal space: https://escholarship.org/content/qt8ss5h8p0/qt8ss5h8p0.pdf
psychologyrocks 