A concrete entrainment Marshall adopted (from Greg Nance via Stepan Parunashvili): a single **Commitments file**. Greg Nance — a reliability-proud startup CEO — noticed that despite his self-image, things were starting to slip: he'd tell someone he'd get them something, and delivery would be haphazard. The normal reaction is to excuse it ("we're all busy"). Nance's reaction was to *engineer* it: he created one "Commitments" file in Evernote, and every single thing he committed to, he immediately wrote down. Then he swept the file daily, or at least weekly. Soon it was second nature — entrainment — and "everything started getting done." Marshall's version: the moment he says he'll do something, he writes it into the Commitments file immediately, or into iPhone notes or an email to himself that gets swept in later. The payoff is categorical, not incremental: "a whole class of behavior — promising to do something for someone — went from being shaky and haphazard to being nearly automatic." The design lesson generalizes (see [[Design Future Responses to Stimuli]]): pick one leaky class of behavior, route it through a single trusted capture point triggered by a clear stimulus ("I just made a promise"), and review on a fixed cadence. Pairs naturally with the [[Daily Upstream Audit]]. --- *Source: [[Book Inventory/Progression|Progression]] (Sebastian Marshall, 2016) — Upstream Effects #2 — Entrainment*