The Anna Karenina Principle: One Flaw Dooms Potential, Not Just People or Products

In biology and business alike, success often depends not on excelling everywhere but on avoiding key failures. The Anna Karenina Principle, borrowed from Tolstoy’s famous line about happy families, applies just as much to domestication as it does to startups, diets, or teamwork: everything needed must be in place, and the absence of a single element can ruin the outcome.

Why can’t zebras be farmed? It’s not for lack of usefulness or intelligence, but because they bite, kick, and panic, making them dangerous and impossible to handle—or because they don’t breed well in captivity. The same goes for many ‘near-miss’ projects: a perfect product with a terrible user interface flops, just as a brilliant student who neglects sleep cannot perform at their best.

Scientific thinking trains us to look at complex systems as interlocking requirements. Some are easy to meet, while others—like trust, health, or a calm temperament—may be the ones that make or break the whole structure. Recognizing 'dealbreakers' early, rather than being dazzled by strengths, is what separates good plans from those doomed to become cautionary tales.

Write down everything your plan, project, or relationship needs to succeed, and zero in on the one element that, if absent, brings everything else down. Just as zebra farmers learned to focus on temperament, you must prioritize potential failures above flashy advantages. Redirect your energy to fix, patch, or work around the true dealbreakers first, and let that focus guide the rest. Give this a honest try with your next goal and see what opens up.