Answer:
i think its mating gradient
Step-by-step explanation:
cohabitation is living together but not in a relationship. i know that much.
endogamy is marrying within limits of a clan or tribe or group.
mating gradient is this:
In more general terms, the mating gradient means that when men increase in status, they widen their pool of eligibles; when women increase in status, their pool of eligibles becomes narrower, leading to an exacerbation of the female marriage squeeze.