Each generation, every family is re-woven: a child’s place is part inherited from the parent and part fresh merit plus luck. The inheritance weight is how tightly the thread is tied to the one above it.
Quintiles are always fifths — 20% at every rung by definition. So what changes is not the shape of the ladder but the flows between rungs. Sociologists call the diagonal of that flow matrix the stickiness of a class.
Nudge inheritance from one-half toward four-fifths and something abrupt happens: the weave locks. Born at the bottom, die at the bottom — even though every family still “works hard.” That is how a class quietly hardens into a caste.
An opportunity floor — schools, credentials, networks opened to the poor — loosens the thread for those at the bottom without touching what the rich pass down. It is the one lever that reopens the loom while inheritance stays high.
Something in the simulation stopped unexpectedly — the lesson continues without it. Nothing you did was wrong; you can move on.