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The psychology of human misjudgmentPart II

Drug-misinfluence tendency

Chemical dependency degrades cognition and ethics.

Drug-misinfluence tendency illustration

One of Munger's bluntest tendencies. Drugs (alcohol, recreational, prescription, dependency on any chemical) erode judgment and ethics in ways the user almost always underestimates. The dependency convinces the dependent that they're functioning normally well past the point where they're not.

The reason Munger included this in a list of cognitive biases is precisely because it's a cognitive bias, not just a substance problem. The brain rewrites self-perception to accommodate the dependency. Most addicts genuinely believe they're functioning fine.

For operators, the implication is to take chemical dependency seriously when you see it in colleagues, hires, or yourself, even when the behaviour looks high-functioning. The trajectory is almost always downward. Early intervention is much cheaper than late.

Examples in the wild

Operating

Finance and tech industries have systematically higher rates of substance dependency than the average population. The wreckage in senior careers is real and well-documented.

Investing

Many of the most spectacular trader implosions had substance dependency as a contributing factor. The dependency was hidden until the crisis revealed everything at once.

Everyday life

Mild dependencies (daily wine, daily anxiety medication, daily caffeine to the point of withdrawal) shape behaviour and judgment more than the dependent person typically admits.

Drug-misinfluence tendency is one of the mental models we apply through real cases inside the Pareto MBA — a part-time program for professionals who want to think clearly about business.