Every system has a self-righting zone and a self-intensifying zone.

Some systems are convex: self-righting.

When the system is perturbed out of equilibrium, the internal forces naturally pull it back to equilibrium, with the magnitude of force scaling with how far out of equilibrium.

Some systems are concave: self-intensifying.

When the system is perturbed out of equilibrium, the internal forces naturally pull it further out of equilibrium, with the magnitude of the force scaling with how far out of equilibrium.

Convex systems are antifragile and stable. Concave systems are inherently unstable and dangerous.

But even convex systems have a range beyond which they flip into the other mode, when they're pushed too far out of equilibrium.

It's better to view every system as fundamentally having a kind of rounded m shape, where at the extremes it is self-intensifying, but in the middle there is a dip that is self-righting.

In some cases, the dip is very large and deep, and the self-righting behavior dominates in all but the most intense situations.

In other cases, the dip is barely present, and the self-accelerating behavior dominates in all of the least intense situations.

How big the dip is in a system is how effective it is at absorbing unexpected variance and still staying stable.