Any sociological definition of a family must be able to accommodate the ubiquity of non-monogamous relationships across cultures.
In his work, George Peter Murdock found that 195 societies in his sample were non-monogamous, while only 43 were comprised of monogamous couples. Therefore, his sociological construct of the family needed to reflect the prominence of polyamory. In defining the family unit as a shared residence, economic cooperation, and reproduction, he was able to accommodate non-monogamous relationships where multiple sexual partners lived under the same roof and took part in domestic responsibilities.
[P1] Many families across the world are not monogamous. [P2] Therefore, any definition must allow for monogamous relationships. [P3] Even polygamous relationship share a home, have a degree of economic cooperation, and reproduce. [P4] Therefore, Murdock's classic definition of a family is the most accurate.