Answer
Haldane's response refers to Hamilton's kin selection theory. In Haldane's mind, the cost of sacrificing himself to save the drawing man would be 1 because he is linked to himself by r = 1.0.
He would be more apt to save two brothers because he would be linked to each brother by r = 0.5. The benefit of saving two brothers would therefore be 2(0.5), which equals 1--the same benefit as saving himself.
Moreover, he would be linked to each cousin by r = 0.125. If he were to save eight cousins, the benefit would therefore be 8(0.125), which equals 1. Again, this is the same benefit as saving himself.
In other words, Haldane says that, for the same cost as his own life, he could save two brothers or eight cousins, which makes more sense that risking his life to save just one person.
Work Step by Step
Haldane's response refers to Hamilton's kin selection theory. In Haldane's mind, the cost of sacrificing himself to save the drawing man would be 1 because he is linked to himself by r = 1.0.
He would be more apt to save two brothers because he would be linked to each brother by r = 0.5. The benefit of saving two brothers would therefore be 2(0.5), which equals 1--the same benefit as saving himself.
Moreover, he would be linked to each cousin by r = 0.125. If he were to save eight cousins, the benefit would therefore be 8(0.125), which equals 1. Again, this is the same benefit as saving himself.
In other words, Haldane says that, for the same cost as his own life, he could save two brothers or eight cousins, which makes more sense that risking his life to save just one person.
