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Equation 8 · Part 2 · Why We Punish Strangers: The Evolution of Human Cooperation

≈

r≈0r \approx 0
≈

What this part means

Approximately equal to; the equality is not exact.

Its job in the formula

Approximately equal to; the equality is not exact.

The passage around this formula

What the rule does not do is scale. Relatedness falls by half with each step of genealogical distance — a full sibling carries r = 0.5 , a first cousin r = 0.125 , and by the time two people are unrelated in any traceable genealogical sense, r is effectively zero. Set r ≈\approx 0 into Hamilton’s inequality and the right-hand side has to do all the work: either the benefit to the recipient must be extraordinary or the cost to the actor negligible, for almost every real transaction between strangers. That condition does hold for some human behavior — warning a stranger about to step in front of a car costs almost nothing and saves a great deal — but it manifestly does not hold for the…

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A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.

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Sources cited in the article section

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