The coefficient of relationship is sometimes used to express degrees of kinship in numeric terms in human genealogy.

When curious, Brain will propose the question of heritage and bloodlines, only to come to the question that resides somewhere deep inside itself, because Brain is that kind of parasite. When bored, Brain will wonder about the We and how it is holding it’s lineage, how it is suspended together in the space of blood or in the space of cells or in the space of bodies that are controlled by Brain and only by Brain, because Brain is that kind of narcissist.

In population genetics, the coefficient of relationship is a value between 0 and 1 that gives the probability that any two individuals share an allele at a given locus by virtue of being descended from a common ancestor. It is often denoted r.