The theory is based on the hypothesis that cooperation helps in transmitting underlying genes to future generations either through increasing the reproductive successes of the individual (direct fitness) or of other individuals who carry the same genes (indirect fitness).
A teoría está baseada na hipótese de que a cooperación axuda a transmitir xenes subxacentes a futuras xeracións ao incrementar o éxito reprodutivo do individuo (fitness directa) ou o doutros individuos que levan os mesmos xenes (fitness indirecta).