Exogamy has two related definitions, both biological and cultural. Biological exogamy In biology, exogamy more generally refers to the mating of individuals who're relatively less related genetically: that's, outbreeding as opposed to inbreeding. This benefits the offspring by avoiding the chance of the offspring inheriting two copies of a defective gene, and also by increasing the genetic diversity of the offspring, improving the chances that more of the offspring will have the required adapt… (More on Exogamy)