Consanguinity is the measure of how closely people are related. Genetic relatedness measures how many genes a person shares. As humans share many of the same genes, people can be related in more than one way, and inheritance of genes has a random element to it, these two concepts are different. Consanguinity decreases by half for every generation of reproductive separation through their most recent common ancestor. Siblings are 50% related by consanguinity as they are separated from each other by two generation (sibling to parent to sibling) and they share two parents as common ancestors (formula_1).