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Equation 2 · Part 1 · Why We Punish Strangers: The Evolution of Human Cooperation

Symbol r

rr
rr

What this part means

the coefficient of relatedness between the actor and the recipient.

Its job in the formula

r is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Where the article explains it

Here r is the coefficient of relatedness between the actor and the recipient, b is the fitness benefit the recipient gains, and c is the fitness cost the actor pays.

The passage around this formula

Here r is the coefficient of relatedness between the actor and the recipient, b is the fitness benefit the recipient gains, and c is the fitness cost the actor pays. A gene that disposes its carrier to help a relative will spread whenever the benefit to the recipient, discounted by how likely the…

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Learn the underlying idea

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 surrounding passage

These citations provide research context; check each source for the exact claim it supports.