Only big cities lend themselves to the kind of anonymity (“magna civitas, magna solitudo”) and benign incuriosity that permits one to start over again with a clean slate, to try on one mask after another until finding the one that fits.

There’s a curious resonance here with Whyte’s work on sidewalk sociality. In his telling, the act of striking up a conversation mid-path owes much of its power and appeal to the paradoxical fact that – being in the middle of the flow – a participant isn’t overly committed to remaining in any one particular engagement. Not being trapped by some obstructive feature of the physical environment means they can leave at any time…and are therefore that much more likely to enter into, and maintain, a conversation.

If Holly Whyte taught us that low commitment and low risk, in this context, means a willingness to experiment, the same thing is true of big cities and identity. You can try stuff on for size – a haircut, a style, a dietary habit, a declared political or sexual stance – and leave it behind a week later if it doesn’t suit. (Try that in a small town and see what happens.)

Expressed as a more general principle, I’d say that big cities are all about lowering the opportunity costs of action, and enabling more supple transitions from one planned activity to another. It’s something that I believe can and ought to be designed for in all urban environments.