I got to wondering what is man’s natural state regarding pairbonding. Is the monogamous marriage and nuclear family that religion has pushed on us the natural state of man, is it the nihilistic anything goes culture we have now, or or are we kidding ourselves with our silly religion and -isms and are our natural instincts compelling our behavior? What insights are gleamed by the mating behavior of other primates?

The following are excerpts from https://www2.palomar.edu/anthro/behavior/behave_2.htm

Monogamous Family Group One male one female children go off and make their own monogamous family units. While this group pattern is the most common one for humans (allegedly) it is rare for non-human primates.  monogamous family groups are the common pattern for gibbons, siamangs, titi monkeys, indris, tarsiers, and apparently some pottos. Polyandrous Family Group The smallest New World monkeys, the marmosets and tamarins, form both monogamous and polyandrous family units.  They generally start with a monogamous mating pair.  Later, a second adult male may join the family and assist in child rearing.  When this occurs, both adult males will potentially mate with the adult female.  This arrangement is PRACTICAL... because these monkeys commonly have twins and the FATHERS carry the babies around on their backs most of the time.  One-Male-Several-Female Group One-male-several-female groups have polygynous mating patterns.  That is to say, one male regularly mates and lives with more than one female at a time.  The male and his female mates form a distinct mating and child rearing group.  This pattern is found among hamadryas baboons, geladas, langurs, howler monkeys, gorillas and MANY HUMAN SOCIETIES. It has been a culturally preferred marriage pattern in numerous Native American, African, and South Asian cultures.  However, polygyny is not as common among humans as monogamy, even in cultures that advocate it.

Multimale-Multifemale Group The most common social group pattern among semi-terrestrial primates is the multimale-multifemale group.  With this pattern, there are no stable heterosexual bonds—both males and females have a number of different mates.  This is characteristic of savanna baboons, macaques, as well as some colobus and New World monkey species. Multimale-multifemale groups commonly have a dominance hierarchy among both males and females.  Each individual is ranked relative to all other community members of the same gender.  The top ranking individuals are referred to by primatologists as the alpha male and the alpha female

Fission-Fusion Society A fission-fusion society is one in which the social group size and composition change throughout the year with different activities and situations.  This is the social pattern typical of chimpanzees (what humans are closest to) Individuals enter and leave communities from time to time.  Adult males occasionally wander off and forage alone or join a few other males in a hunting party.  Females casually change membership from one group to the other.  This occurs especially when females are in ESTRUS AND SEEKING MATES. As a result, foraging and sleeping groups reform frequently.  Male chimps are the relatively stable core of the community since they rarely join other troops. What allows for the generally loose relationship between chimpanzee communities is that they apparently recognize a wider range of social bonds than do monkeys.  When chimpanzee communities come together, they usually exchange friendly greetings rather than show aggression.  However, it would be a mistake to assume from this that chimpanzee society is always peaceful.  The adult males within each community are frequently engaged in complex political activities involving scheming and physical intimidation in order to move up the dominance hierarchy.  They develop short-term alliances with other males by mutual support. It isn't always the largest and strongest males who make it to the top of the hierarchy.  Often teamwork used to frighten and impress is more effective than any one individual's muscles in achieving chimpanzee goals.  This is an indication of their intelligence.