Confirmation bias is the ability of the mind to seek out evidence that conforms to its own theories and simply gloss over or completely ignore contradictory evidence.

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Such a calculation is polluted by what's called survivorship bias--the ability of fund vendors to make bad funds disappear.

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Unfortunately, the mantra of skeptical research can continue past its usefulness, as those of us accustomed to being rewarded for our ability to critically assess rapaciously search out bias and inaccuracy all around us.

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The bias towards co-investors on measures of ability is weaker: investors with degrees from the best universities are just 9% more likely to get together.

ECONOMIST: Choosing co-investors

The bias affects our idea of our own intelligence as measured by IQ, how we judge our ability to think, our notion of our own relative academic records, test results, health, even ability to drive a car and be popular among friends.

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