Inspired by Malcolm Gladwell’s Revisionist History podcast, Lee Davy, takes a look at how the threshold model of collective behaviour slows the flow of poker and how dealers could speed it up.

My son and I are having dinner.

He’s a bag of nerves; fidgety, his fingers always working, adjusting a lapel, a button, or shaping his hair. A group of lads his age walk in and take a seat next to us. I see another change; more solemn this time, the conversation is stilted, the tone is quiet, almost imperceptible.

I look across at the lads.