Equation 6 · Part 2 · Why We Punish Strangers: The Evolution of Human Cooperation
=
=
What this part means
The expressions on both sides represent the same quantity under the stated assumptions.
Its job in the formula
The equals sign connects the complete expression on the left with the complete expression on the right. Both sides must have compatible units.
Full expression→=→Article meaning
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 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…
Learn the underlying idea
An equals sign says that the expression on its left and the expression on its right have the same value under the stated definitions and assumptions.
Open the illustrated equality: what the equals sign claims guide →
Sources cited in the article section
These citations provide research context; check each source for the exact claim it supports.