Leo Tolstoy’s 800-page masterpiece Anna Karenina opens with one of the most famous first lines in history:

Happy families are all alike; every unhappy family is unhappy in its own way.

-Leo Tolstoy, Anna Karenina

What Tolstoy means is that happy families share a similar set of attributes that lead to their happiness: things like good communication, expressing love, showing affection, spending time together, supporting each other, having mutual respect, a certain level of financial security, and the like. But a deficiency in any one of themresults in unhappiness. Thus, a variety of circumstances or attributes can lead to unhappiness and dysfunction.

While there is truth in Tolstoy’s statement, it is an oversimplification — each happy family is different, and happiness doesn’t depend on following an exact blueprint. That being said, Tolstoy’s sentiment carries wisdom; happy families do share similar attributes.

This concept — that success requires multiple factors to be present, and the absence of any one factor results in failure — is known as the “Anna Karenina Principle.” Or as the American painter Edward Simmons said, “The difference between failure and success is doing a thing nearly right and doing a thing exactly right.” Or Aristotle’s notion that “It is possible to fail in many ways . . . while to succeed is possible only in one way (for which reason also one is easy and the other difficult – to miss the mark easy, to hit it difficult).”

Application of Anna Karenina Principle

At its essence, the Anna Karenina Principle stands for the notion that there are many more ways for something to go wrong that for it to go right.

The principle was popularized by Jared Diamond in his fantastic Pulitzer Prize-winning book Guns, Germs, & Steel, where he described the myriad factors necessary for an animal species to be domesticated (e.g., dietary needs, captive breeding, disposition, panic tendency, and social structure). The principle has been applied to

• scientific discovery,
• animal microbiomes,
• customer service (all happy customers are alike; every unhappy customer is unhappy in their own way)
• Project management
• Management of family offices,
• Consciousness,
• Successful schools
• Successful businesses

How to Use this Mental Model

The idea that success requires multiple factors to be present is an important mental model. To use this mental model, explore the best practices needed for success with special emphasis on those that are essential to success. You can’t just focus in just one area — success requires competency across multiple areas.

For example, to be a successful athlete, you need appropriate:

• Genetic attributes for the sport (e.g., basketball favors height, certain body types are better for distance running than others, etc.)
• Nutrition
• Fitness training
• Skill development
• Coaching
• Time and effort spent practicing (deliberate practice is the best)
• Leadership and team focus

I may be missing a few, but you get the picture: Failure to focus on any of the above areas will result in failure. If you are an aspiring athlete, consciously listing out the necessary elements of success and ensuring that you focus on them can boost your odds of success.

Similar lists of best practices can be made in all sorts of areas: Career success, building a strong business, being a good spouse or parent, and so on. Deliberate focus on developing all necessary factors for success will be more productive than haphazardly working towards success.