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Why Evolutionary Theory is Wrong about Sex

Modern evolutionary theory is based upon the idea that human beings are “designed” (their term) to be promiscuous. The basic idea is that women have sex with multiple men until they find one with the best genes. And men have sex with various women until one chooses him to father her child. Men are seen as being driven by the desire to pass their genes on to the next generation, so they search out women who will give them the greatest opportunity for success.

A recent book by the founder of the Medical Institute for Sexual Health, Dr. Joe McIlhaney and his co-author Dr. Freda McKissic Bush, calls this theory into question. Their book Hooked: New Science on How Casual Sex is Affecting our Children shows that just the opposite is the case. Rather than being “designed” for promiscuity, human beings are actually designed to be sexually monogamous with one mate for life.

What lead them to this conclusion? The primary reason is the recent data that has come to light regarding the inner-workings of the brain. The authors conclude: “But now, with the aid of modern neuroscience and a wealth of research, it is evident that humans are the healthiest and happiest when they engage in sex only with the one who is their mate for a lifetime” (p. 136). So, what specifically has brain research revealed?

The most important sex organ is the brain. It is the most complex physical structure in the known universe. Despite common misperceptions, the brain is not fully mature until around age 25. Thus, our decisions, behavior, and thoughts actually form the physical structures of our brains as we develop. The brain is composed of neurons (the primary cell of the brain), support cells (that strengthen the neurons), synapses (which generate communication between neurons), and neurochemicals. Thus, premarital sex and activities such as viewing porn short-circuit the proper functioning of the brain, and can damage to proper human development.

For example, one of the key neurochemicals in males is vasopressin, known as the “monogamy molecule.” Vasopressin has two primary functions in relationships—bonding to the spouse and attachment to the offspring (p. 41). Vasopressin is the primary cause of bonding between a man and another woman of whom he is in close contact. It has been studied in prairie voles (small mammals that live in the grasslands of the Midwest and are amazingly monogamous). Studies have shown that when the flow of vasopressin is blocked, male voles did not bond to females with whom they were sexually active. However, when the brain is flooded with vasopressin, as is supposed to happen in mating, the male vole shows increased attention and attachment to the young (p. 42). Vasopressin is the neurochemical that generates bonding, attachment, and commitment between a male and his mate. Multiple sex partners (as well as pornography viewing) short circuits the proper release of vasopressin and leads to the inability to bond with one spouse. Those who have multiple sex partners, says Hooked, “risk damaging a vital, innate ability to develop the long-term emotional attachment that results from sex with the same person over and over” (43).

Rather than being “designed” by nature for promiscuity, it seems that the brain is actually intelligently designed for sexual monogamy. Hooked clearly demonstrates that the further individuals deviate from this behavior, the more problems they encounter, whether STDs, nonmarital pregnancy, and emotional problems including damaged ability to develop healthy connectedness with others, including future spouses.

Sex is not the accidental by-product of evolution that helps us pass on our genes to the next generation. It is the purposeful creation of a loving God who has set out the guidelines through which it is best experienced.
Tags | evolution | sex


All the more reason to cut off your right hand if it causes you to sin. Through masturbation you'll lose your soul AND your brain. This time science is on our side. Hallelujah! God is Great!

Masturbation is sex with self right? Isn't that like "same -sex" sex?

You do realize that you don't understand what evolutionary theory says about sex, promiscuity, and pair bonding?

I think this study raises some very good points, but what amazes me is how open-minded academics are now catching up with ancient wisdom.

Danger awaits the unwary who try to have an argument both ways.

For example, if one argues that God and not evolution "designed" man, then one also introduces the presumption that God designed man for some purpose because God is an intelligent, self-integrated agent acting according to his own designs. As a consequence, design and purpose become inextricably intertwined such that every characterization of a designed aspect of man is a characterization of its designer's purpose and of the designer himself. Such characterizations invite theological folly, for who are you, O man, to talk back to God?

In contrast, if one argues that evolution designed man, then there simply is no considered purpose for any aspect of that design. This introduces the presumption that a design aspect fulfills some purpose for the organism itself, such as survival advantages relative to other organisms and the environment. Relying on this presumption, evolutionary anthropologists presumed that more sex between more people must be better because it leads to more offspring with better genes. This is not the case, but see how the presumption worked to lead those who indulged it in the wrong direction? Time again, this false presumption has worked the same mischief.

The correct evolutionary presumption is that any particular design aspect may fulfill no purpose at all, and may even impose disadvantages on the organism who survives despite the same. Therefore, the argument that man is as he "should" be as a consequence of his evolution does not follow, revealing the truth that each man is free to design himself to some extent.

"Danger awaits the unwary who try to have an argument both ways."
RCB, you sound like you are the one who is trying to have the argument both ways. Doesn't evolution claim that things evolve in order to survive--for survival of the fitest? So if there is no survival reason that drives a creature to devolop some trait, there is no mechanism to make it evolve into being. You can't on the one hand say creatures evolve in order to survive, but on the other say that they produce purposeless changes.

If you will look at the evolutionary presumption, you will find a total denial of design.
The accepted defination of evolution implies toltal random chance and nothing of design.

If a man is free to design himself, how is he able to change his genes to pass his self made design on to future generations? If you can not change the design of the lung or the eye to improve your offspring, you cannot change anything else about yourself to create a future changed individual.

This article is very good, except for the following paragraph which seems amazingly lacking in logic steps from the original conclusions.

the further individuals deviate from this behavior, the more problems they encounter:

Ostensibly yes, but the examples seem very contrived and don't fit into cause and effect properly.

a) STDs, this surely is a side effect. This can be contracted even if the individual is monogamous, depending not only on the mate, but even if the mate is monogamous this can occur from multiple other causes. Yes if sexual activity is increased the risk increases, but it's not a direct logic link and not the only link. Not only that, precautions can be taken to avoid STDs even when promiscuous, showing that it could well be mitigated even by promiscuous people. It's rather loose and imho a clear attempt to change people's behaviour to conform with the writer's opinions. I'm not saying I disagree with the moral aspects - I agree, it's just that this does not seem to be science any more. It does an end run around science and makes our position weaker not stronger.

b) non-marital pregnancy. Ignoring what "marriage" is defined as (to me it's a life-time commitment to each other. I can't say before God since most people are not believers.) Pregnancy again is a side issue. If people are careless this would be true, but there are many non-monogamous people who will not experience pregnancy so therefore this would not happen and not indicate lack of monogamy.

c) damaged ability to develop healthy connectedness with others - maybe, but I see no data showing this.

d) including future spouses - so this indicates that those who deviate from monogamous behaviour are likely to have unhealthy connectedness with future spouses? Again this seems a little strange and out of context. Surely if it produces a problem with future spouses, then if the person is married at the time it would damage the relationship with the current spouse also. Why the rider "future"?

This was going very well until this penultimate paragraph indicated that there's perhaps a hidden agenda here, at least it smells strongly of that purpose. It's a pity really. The conclusions are what I would like to see, but sadly, going about it this way makes the theory unusable for those who wish to see scientific support for a moral lifestyle.

Maybe, if the wording was dramatically changed it would work. But I don't see this paragraph helping your cause. It seems so contrived and it's a bit like fitting the theory to fit the desired conclusions. Not a good way to prove your point.

It's a great pity since I'd love to use this data and conclusions.


David, your argument falls flat on all 4 points.

STDs being the most clearly established "effect" from a "cause". There is a plethora of scientific data establishing this fact over the past five decades. Your hypothetical arguments surrounding STDs are quite ignorant and wouldn't stand against a 5th-grade, public school sex education pamphlet.

Babies born out of wedlock is another slam-dunk. You cite this sentence: "the further individuals deviate from this behavior, the more problems they encounter"
This IS a huge "problem" area, and well established with decades of scientific data. The cost to children has been devastating and the load on government social, judicial and rehabilitation programs is undeniable.

c & d are related. And again there is extensive data to support the claim. Divorce rates are much higher among those who engaged in frequent sex with multiple partners before that marriage. Clearly this is aneffect on "future" spouses - just as there is an impact on future spouses among those that divorce the frist time.

I realize it's much easier to simply make your claims, but do yourself a favor, do some digging first.

Taking this article one step further, the true implications of polygamist marriages. Evidence of this article's validity can be easily seen through the children in polygamist situations who suffer and men who are not connected with any of their wives the way monogamy relationships are. "Multiple sex partners (as well as pornography viewing) short circuits the proper release of vasopressin and leads to the inability to bond with one spouse."
Typically in polygamist situations, children suffer the most. A great example of the negative affects caused by men not bonding with their children, specifically in polygamy, is an account from Brent W. Jeffs in his book Lost Boy. The feeling of having no value and not being special in any deeper sense in polygamist children is obviously linked to the blocking of vasopressin in their parents. The effects are easier to see in polygamist circles, although extend to any individual with children who have had multiple partners.
Any thoughts on this connection are appreciated

I think that the authors intent to point out that all sexual activity oriented to self based, short term fulfillment is likely to cause negative side affects such as brain malfunctions,relationship difficulties, and mental insecurities in children is very realistic.
However from a scientific point of view the article is very unprofessional, there are to many generalities and a lack of detailed scientific data. There a serious lack of data on long term multiple relationships of both mammals and humans.
All your statements with regards to polygamist situations are assumptions and loaded statements which indicates you have a primary agenda. The fact that there is a child from polygamy that has a identity issue and writes a book does not mean anything.
With respect to the fact that children in both monogamy and polygamy have identity issues ,it probably has more to do with the maturity and objectives of the responsible parties.To make a simple statistic about the polygamy in general one should gather all possible information recorded, then make comparisons on all issues

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Sean McDowell is a teacher, author, speaker, husband and father. He is an avid fan of college basketball, ping-pong, and his favorite superhero is the Amazing Spiderman.