Log in

Anthropologist Community
Are Humans Meant to be Monogamous? 
19th-Mar-2008 02:28 pm
Jeanna Bryner LiveScience Staff Writer

News of politicians' extramarital affairs seems to be in no short supply lately, but if humans were cut from exactly the same cloth as other mammals, a faithful spouse would be an unusual phenomenon.

Only 3 percent to 5 percent of the roughly 5,000 species of mammals (including humans) are known to form lifelong, monogamous bonds, with the loyal superstars including beavers, wolves and some bats.

Social monogamy is a term referring to creatures that pair up to mate and raise offspring but still have flings. Sexually monogamous pairs mate with only with one partner. So a cheating husband who detours for a romantic romp yet returns home in time to tuck in the kids at night would be considered socially monogamous.

Beyond that, scientists' definitions for monogamy vary.

Original Article or

Evolutionary psychologists have suggested that men are more likely to have extramarital sex, partially due to the male urge to "spread genes" by broadcasting sperm. Both males and females, these scientists say, try to up their evolutionary progress by seeking out high-quality mates, albeit in different ways.

The committed partnership between a man and a woman evolved, some say, for the well-being of children.

"The human species has evolved to make commitments between males and females in regards to raising their offspring, so this is a bond," said Jane Lancaster, an evolutionary anthropologist at the University of New Mexico. "However that bond can fit into all kinds of marriage patterns - polygyny, single parenthood, monogamy."

The human species is somewhat unique amongst mammals in that fathers do invest in raising children.

"We do know that in humans we do have this pretty strong pair bond, and there's more paternal investment than in most other primates," said Daniel Kruger, a social and evolutionary psychologist at the University of Michigan's School of Public Health. "We're special in this regard, but at the same time like most mammals, we are a polygynous species." Kruger said humans are considered "mildly polygynous," in which a male mates with more than one female.

Whether or not the married or otherwise committed individuals stray for sex depends on the costs and benefits.

"There is plenty of evidence that males have less to lose than females by having extramarital sex," Lancaster said. "Having less to lose, it's easier for them to do it."

Women, however, could lose "dad's" resources when it comes to raising their kids. "For women, the well-being of their children is not improved by promiscuity," Lancaster told LiveScience.

Some scientists view both social and sexual monogamy in humans as a societal structure rather than a natural state.

"I don't think we are a monogamous animal," said Pepper Schwartz, a professor of sociology at the University of Washington in Seattle. "A really monogamous animal is a goose - which never mates again even if its mate is killed."

She added, "Monogamy is invented for order and investment - but not necessarily because it's 'natural.'"
19th-Mar-2008 07:39 pm (UTC)
I think it's kind of silly that they're looking at it as a species thing. Of course, I also think it's silly to look at monogamy as a gender based thing. I think the real question should be, on an individual level, is monogamy right for this person?

I don't believe it necessarily is or isn't right for every single person or even every person of a particular gender. I do believe however, that those who feel strongly one way or the other should be up front about it, and more importantly, should feel like they can be up front about it. I think that's still a ways off though. Pity.
19th-Mar-2008 08:47 pm (UTC)
Mmm, existentialism, yummy

Of course, whether or not it's "right for this person" will most likely depend on how strongly they were socialized one way or the other.
19th-Mar-2008 10:03 pm (UTC)
"Of course, whether or not it's "right for this person" will most likely depend on how strongly they were socialized one way or the other."

Statistically speaking: true enough.
19th-Mar-2008 10:30 pm (UTC)
Why is it silly to look at it as a species thing? Humans are a species and much of our behavior has is determined by millions of years of natural selection. Especially something as important in evolution as reproduction.
19th-Mar-2008 07:50 pm (UTC)
Short answer: Humans are not monogamous...

However, we do seem to be obligate cooperative breeders--at least in hunter-gatherer societies due to a deficit in energy production by "pair bonded" couples. This shows up in skewed male-female ratios.

Sounds like a recipe for monogamy then, right?

Problem is we also... er... women also have adaptations that alter their perceived sexual attractiveness by where they are in the ovulatory cycle at different ranges. Beyond masking external signals of ovulation/fertility in general, most of the non-ovulatory sensitive period they are perceived as more attractive from a distance and during the most fertile time more attractive when in intimate distances.

Additionally, there are differences in orgasm and possibly fertilization rates in women who practice unprotected sex with more than one male with the advantage going to the "good genes" extra-dyadic partner over the regular social partner.

This speaks of an adaptation towards cryptic female choice for good genes while creating the means to build and maintain social and parental support from other male partners.

In later evolution--like pastoral or agricultural cultures--where the wealth can be inherited and advantage can be non-genetic, this probably becomes even more critical because the fitness of the wealth-holder may be significantly less than other males. Women would sell themselves critically short and have less sexual choice if monogamy was the norm and effectively enforced.

This is--by the way--one reason we males still have large testes and adaptations that alter the quantity and consistency of semen with new women or partners that may have had the opportunity to cheat.

Interestingly, at least one study...

(listed below)

...shows that a male only needs about a .33 to .61 certainty of paternity to demonstrate a reproductive advantage.

Welcome to the Dark Side, we have cookies!

Light reading:

W. O. Shropshire
Human Nature; 2003, Vol. 14 Issue 3, p235-266, 32p

Conditional expression of women's desires and men's mate guarding across the ovulatory cycle
Martie G. Haselton, Steven W. Gangestad
Hormones and Behavior 49 (2006) 509–518
(Deleted comment)
20th-Mar-2008 01:20 am (UTC)

Basically, it's the pair being dependent on the tribe AND having a pretty good percentage of non-reproducing males due to an intentionally unbalanced sex ratio (more males to females).

In a stable system, male-male competition would have to be controlled and sexual access protected.
19th-Mar-2008 10:32 pm (UTC)
You are talking about cuckolding right?
20th-Mar-2008 01:25 am (UTC)
That's one possibility.

Another possibility is the social mate knows and is okay with it.

Another possibility is that it's a polyandrous system.

Another possibility is that it's a somewhat free-for-all situation with multiple males and multiple females involved.

Any or all of those also might show similar adaptations.

Monogamy wouldn't though.
(Deleted comment)
19th-Mar-2008 08:50 pm (UTC)
Technically speaking, nothing which exists is "unnatural" because it still exists within "nature" (in the Spinozan sense where nature is everything). However, you seem to be equivocating the use of the word nature here which, in this context, is referring to the biological aspects rather than the sociological aspects (though a physicalist would make the argument that the sociological directly stems from the biological, but how exactly the mind and body interact isn't exactly well known and will lead us into either monist or dualist answers).
19th-Mar-2008 11:40 pm (UTC)
I can't agree more with you.
19th-Mar-2008 10:28 pm (UTC)
Actually cuckolding by women has its evolutionary advantages and is probably deep rooted in human evolution and may be one of the causes of intense male sexual jealously.
20th-Mar-2008 08:05 pm (UTC)
Can you explain a bit more, or give some evidence as to why cuckolding by women "... is probably deep rooted in human evolution" and why male "cheating" is not?
20th-Mar-2008 08:29 pm (UTC)
Male cheating is as well, I didnt say it wasn't. This post only touched on the male aspect so I felt the need to bring up the female.
20th-Mar-2008 08:31 pm (UTC)
Ah, if you see my comment further down on the post I had the same feeling.
19th-Mar-2008 11:18 pm (UTC)
I don't know why this thing sounds sexist to me. :/
19th-Mar-2008 11:49 pm (UTC) - religion
Also, not all human cultures practice monogamy. It's considered the norm in most Christian societies, and I know a lot of people think monogamy=civilized and developed societies. Like it's somehow a more advanced state of being. But it's certainly not the norm in many societies.
20th-Mar-2008 05:33 am (UTC)
Meant to be? No, extremely unlikely if dogma isn't employed. Monogamy is socially constructed. The primitive man's instinctual goal was to survive and populate, he would roam the earth in search of food, fights, and sex (but much has changed!). If he happened to come across a defenseless woman, that was it, he would hit it quit it. Then, man began to "keep" the woman(s) around as a convenient way to release his sexual urges. ~They bonded.~ It was also at this point that man began to bond with his children and come to recognize them as a part of himself. Man learned through experience that there was strength in numbers - necessities could be obtained more efficiently and aggressive strangers were easier to handle. Thus he remained with his kin and as time progressed civilizations were formed. Out of these civilizations sprang all kinds of rules and regulations pertaining to social conduct, one of which was monogamy. There is nothing "wrong" with polygamy, however if you commit yourself to a single person and have them believe you're monogamous, you can't go hopping into bed with various others and then blame human nature when you're found out.
20th-Mar-2008 08:07 pm (UTC)
Am I the only one to take issue with, "Evolutionary psychologists have suggested that men are more likely to have extramarital sex, partially due to the male urge to "spread genes" by broadcasting sperm."

The author must be postulating that there is a major population of unmarried women for these married men to have sex with, because these men have to have sex with SOMEONE ELSE to have extramarital sex...
20th-Mar-2008 08:30 pm (UTC)
A cheating male can only have sex with unmarried women?
20th-Mar-2008 08:32 pm (UTC)
No, if men are more likely to have extramarital sex, then the male must be having sex with unmarried women or else women and men will have the same amount of extramarital sex.
21st-Mar-2008 04:37 am (UTC)
Evolutionary psychologists have suggested that men are more likely to have extramarital sex, partially due to the male urge to "spread genes" by broadcasting sperm. Both males and females, these scientists say, try to up their evolutionary progress by seeking out high-quality mates, albeit in different ways.

Huh. Are evolutionary psychology and sociology at odds with each other then? Because many men who are "biologically predisposed" to spread their spermies have absolutely no interest in assuring the survival and well-being of their offspring. In fact, many men try to make sure that their partners don't get knocked up.


Edited at 2008-03-21 04:44 am (UTC)
This page was loaded May 28th 2017, 8:30 am GMT.