Equation 5 · Part 1 · Why We Punish Strangers: The Evolution of Human Cooperation
Symbol r
What this part means
effectively zero.
Its job in the formula
r is part of the quantity the equation computes from the expression on the right.
Full expression→Symbol r→Article meaning
Where the article explains it
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.
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…
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.
Open the illustrated variables: a letter stands for a value guide →
See this notation across published equations →
Sources cited in the article section
These citations provide research context; check each source for the exact claim it supports.