If we look we may find that direction and goals can emerge in biological evolution from a mob of directionless and goal-less parts, without invoking vitalistic or supernatural explanations.
In particular, they measured how closely the nestholders were willing to approach the stuffed intruder, and also how noisily the intruder was mobbed, in an attempt to drive it away.
But according to Professor Drury, in reality it's not mob mentality and violence, but rather feelings of safety and togetherness that actually characterise crowds.
Perry loved the work but grappled with the notion of fame, exasperated by mobs of screaming fans, the sheer loss of privacy and perhaps most of all the exalted status of teen idol.