Why Your Girlfriend Wants to Cheat On You




(and Why She’ll Never Admit It)

*Note: This post is a carryover from an old blog. It’s the post that played a large part in the impetus for this site, but looking back now, parts of the theory and explanation kinda make me cringe. I’ve included it in its unedited original version because it still may be of interest to some.
Forget everything you know about society. Forget everything you know about culture. Forget everything you know about psychology. Forget everything you know about relationships. If the topic of this article doesn’t destroy your conception of reality, I’ll be forced to keep writing until it happens.

How’s that for an opening salvo, eh? The problem is that claims such as these have been recited so many times that their potency isn’t what it should be. Since you probably haven’t forgotten everything I told you to forget, you may not realize the irony there.

“Hey Andrew, I’m trying to find out why my girlfriend wants to cheat on me with four entire categories of dudes, what’s up with the socio-cultural-whatever nonsense?”

The Zillion Dollar Question

Gentlemen, let’s face it, the reason you’re reading this is because you know that on some level, your girlfriend has cheated on you wants to cheat on you. Deny it publicly all you want; you’ve seen the footage of the girls practically fainting by the thousands in the proximity of Elvis and The Beatles and… um… The Jonas Brothers? I’ve certainly taken a girl to a concert and looked over at her to see her eyes locked in a distant, creepy trance as her sweat-drenched, dancing body bounces around while she gazes in the generally undistinguishable direction of the singer, guitar player, or (gasp) drummer.

We all know the stereotypes of girls being strangely attracted to painters, basketball players and anyone who can even fake a Scottish, English, Australian, Spanish, Italian, South African (et al) accent. It’s easy enough to write this all off as a phase or a quirk or something. It’s also easy to launch into jealousy though. When was the last time you had this thought process:

My girlfriend (wife) is a sweet girl of high moral standing who’s totally in love with me. Sure, she talks about how hot the singers of her favorite bands are, but even if she had the chance to act on that, she wouldn’t. She’s in love with me and she knows that that guy wouldn’t love her like I do. It’s just a fantasy.

Newsflash: Multiple studies have confirmed that women are overwhelmingly more likely to cheat on their partner during the two or three days of ovulation. During this time, hormones alter a woman’s behavior to the point that otherwise rational and emotional arguments against cheating are fundamentally altered. Emotions, culture, and society may be telling her that cheating is bad, but her body is telling her to mate with the best man she can get. Here’s the rub: The idea of what constitutes “the best man” also changes during that time. The good news is that you’re pretty safe for about 27 days of most months. To be fair, if her body chemistry is artificially altered by birth control pills, this instinct may be tempered.

Disclaimer: To my knowledge, I’ve never been cheated on by someone I was in a relationship with so don’t try to write this all off as some sort of personal vendetta. But… who knows what will be revealed in the comments!

So what is it that inspires the loveliest of girls to want the sex with the boys they wouldn’t give the time of day if they were working behind the counter at Starbucks? I mean really… Are we to just write this off as hormones?

Okay, confession time: The first paragraph in this article wasn’t really me talking. I mean… It does use the fine art of paraphrasing to describe the mashed potato effect my brain experienced when I started learning about this “new science”, but I’m not the first to stand on the mountaintop and hurl such declarations at the content masses. The paradigm shattering message was first trumpeted in 1871 by one of the titans of psychology. You know, that guy you’ve only seen in sepia toned photographs. Yeah yeah, they’ve probably since been edited to appear in black and white, but the OG photographers shot the dude in sepia. Let’s not quibble. Anyway, this chap you’ve seen a zillion pictures of came up with the basis for this science and published it in 1871. Nobody listened. His ideas were patently rejected on moral arguments veiled in scientific rationalizations.

So now the questions you’re asking are: “Okay Andrew, if nobody listened to Freud, how did he go on to become the titan of psychology we know him as today? Why have I seen him over and over in the disputed black and white photographs?”

Evolutionary Psychology

Wait… You thought we’ve been talking about Freud? Silly rabbit… Most of Freud’s theories have since been debunked. Let’s not mention his name again please. The mad genius who attempted to destroy the realities of everyone based on his new understanding of human psychology was Charles Darwin. That’s right… He tried to pull off the ultimate and change the entire understanding of humanity… twice. The guy who had already destroyed everyone’s reality by publishing The Origin of Species in 1859, sought to do it again with The Descent of Man, and Selection in Relation to Sex. We’ve been watching religion squirm to adapt ever since.

If put to the task, you could roughly sum up Darwin’s famous work in four words: “Survival of the Fittest”. Despite Darwin obliterating the foundations of culture and religion in this work, the idea was adopted rapidly in the scientific community. It was one of those ideas that a scientist could look at, relate experiences to, intuit, and successfully test. It resonated. It clicked. However, it wasn’t good enough for Darwin. Despite shifting paradigms and proving it, he couldn’t get peacock feathers out of his head.

When most people talk about evolution the conversation tends to focus on survival related issues, otherwise known as natural selection. Diagrams of primates hunched over a little less over time are tossed about to illustrate the point. However, this is only one of the two main components Darwin espoused. The other biggie was organisms’ focus on reproduction, otherwise known as sexual selection. In The Descent of Man, and Selection in Relation to Sex, Darwin laid the foundation for explaining sexual selection in a little less than a thousand pages. To him, it was his most important work ever because it explained the formation of the mind. When I say the mind, I’m not talking about why gray matter is gray. I’m talking about the mechanisms in the brain that do the thinking. Darwin tackled the explanation of why a peacock’s feathers came to be in terms of brains evolving to select sexual partners on the basis of sexual fitness rather than the simple natural selection of utilitarian fitness.

One way we might describe Darwin’s (second) masterpiece in just four words is “reproduction of the sexiest.” Sure, the strong survive, but it’s the sexy that reproduce. And yes, those often overlap.


So let’s get back to the question posed in the title. Survival of the fittest style natural selection describes why your girlfriend wants to cheat on you with an athlete to a large degree. However, in the strictest sense, it doesn’t explain the thought process involved in choosing to mate with someone with visually recognizable survival cues. Natural selection stops short by basically saying that an unhealthy mate would be dead before they have a chance to reproduce in sufficient numbers. This is where Darwin and sexual selection come in. Brains evolved thought processes to recognize cues for reproductive fitness to allow mate selection to occur on an active evolutionary scale. Your girlfriend wants to cheat on you with an athlete because her brain is evolved to recognize cues that indicate an athlete has favorable advantages in both survival and reproduction. Reproductive selection doesn’t stop at offspring. It also involves the ability to enable the offspring to survive.

The point here isn’t to scientifically prove evolutionary psychology. The point is to introduce you to my new favorite science by answering the question in the title. Because of that, I’ll just go ahead and admit that the athlete in the title was a bit of a red herring. No, I’m not saying that athletes have the personalities of fishes. Stop reading so far between the lines.


This is where things get less obvious. What do guitars, vocal chords, and standing on a stage a few feet higher than the crowd have do do with natural selection or reproductive fitness?

The lack of an obvious and rational connection between women’s affinity for musicians and any sort of evolutionary benefit makes it easy for guys to pass off passing comments and crushes as innocent flirtation. To compound the matter, these guys really are totally the opposite of what she’s looking for in a relationship. So when you call her on it, she’ll think you’re overreacting and claim that she’s honestly into you and would never even want a relationship with a guy like that. And that’s the sticky part… She’s telling you the truth. However, there are two or three days every month that she’s not going to joke about it.

The answer to the zillion dollar question is the answer that plagued Darwin after releasing The Origin of Species. What about the peacock feathers!? Peacock feathers don’t help them survive. Not only is there no survival benefit, they make it more difficult to survive. They make their owners easier targets for predation. They require the exertion of extra energy to maintain them. Carrying them around requires extra energy. Growing them requires extra energy. All of these things are exactly contrary to natural selection. Darwin was a mess.

As it turns out, the line between a peacock’s feathers and the outlandish hair, clothing, and tattoos of musicians is short and direct. Both are tactics specifically designed to fly a middle finger at natural selection. Thorstein Veblen coined the term “conspicuous consumption” to describe ostentatious displays of wealth, but didn’t get around to explaining it to its fundamental levels. Just as conspicuous consumption defies tact and reason by displays of wealth merely as demonstrations of financial wealth, peacock feathers defy natural selection by demonstrating the surplus wealth of a bird’s genes. Only the individuals capable of wasting energy on the growth of cumbersome, easily recognizable feathers could afford to taunt the economy required by strict natural selection. The females (the peahens that nobody ever talks about) don’t have flamboyant feathers. They don’t need them. The females use the feathers of the males to select them as mates. The males don’t have a choice. All they have to do is look pretty and be chosen. See, I told you to forget everything you know about culture and society.

With rockstar level musicians, the peacock type of selection works in an external conspicuous consumption level as well. With increased success comes increased wealth that allows for visible displays far beyond the average individual’s capabilities. I’m not going to spend a lot of time trying to convince you of this. You tell me… How many seasons of “Celebrity Cribs” have aired so far?

But that’s not the end of the story. If it was, the dude with the rad hair and tattoos making your latte would have a less surly demeanor and a lot longer line out the door. To understand the rest of it, you’re going to have to swallow the pill that Darwin’s contemporaries couldn’t. That was in a different millennium, I think you’re ready.

Darwin didn’t stop at physical traits. He included another affront to religion by surgically removing the necessity for God as a foundation for morality. The rejection of his new theories by science was unfortunate, but predictable. Unlike natural selection, reproductive selection rendered large swaths of other sciences irrelevant by suggesting that our thoughts and behaviors are genetically evolved and optimized to perform tasks related to identifying a myriad of cues relating to reproductive fitness.

One of the biggest ideas to come from this is the concept of social proof. Many species have evolved shortcuts to determining the value of mates through social cues. Just like the peacock’s feathers are a shortcut to determining the reproductive fitness of a bird, the rockstar guitar player’s legions of adoring fans are a shortcut to determining his reproductive fitness via the social realm.

In the 1,600,000 years or so of hominid evolution before recorded history, most human interaction took place in small groups and tribes. Under this social framework, brains evolved based on selections within these groups. Genetic and archeological evidence points to an environment in which fewer males had access to females for reproduction. Before language, the easiest way to know what someone was thinking was to watch their actions. If you were a female and saw that multiple females chose a certain male for sex, it was easier to assume they knew something you didn’t. This is especially important because a female’s investment in the reproductive process is significant. A male can get away with a few minutes of investment, but a woman’s investment is measured in terms of years.

The behavior of selecting males based on the mating habits of other females within the species has been observed and documented in a wide range of species including many non-primates.

The importance here is that these shortcuts are selected by minds. The concept of a mind as a determining component of selection explains the rapid growth and current size of human brains much more convincingly than accidental natural selection. The notion of hard-wired social circuitry is also what makes it tough for social scientists to stomach evolutionary psychology despite evidence.

One of the other factors at play with rockstars is that men giving attention to other men is also a useful cue for selection. In the human evolutionary framework, multiple men consistently giving attention to one man in particular tended to indicate leadership and dominance. Women are even more attracted to rockstars that garner attention from both males and females. Predictably, women are less attracted to rockstars in bands that are primarily followed by only men.

Your girlfriend wants to cheat on you with a musician because he stands out in his personal appearance, displays wealth by external conspicuous consumption, and must truly be great because everyone else thinks he’s great.

There’s one other characteristic that applies to some musicians more than others, but it fits more appropriately in the next section.


Yes, artists sometimes embody many of the characteristics discussed above. Stop being so technical so we can get back to the stereotypes and generalizations.

The defining characteristic of the artist is the creativity that springs from individuality. This is a more advanced characteristic of sexual selection because it involves the mind selecting others based largely on others’ minds. This sort of selection can rapidly spread through species. Humans do mind-based selection better than any other animal.

Artistic creativity and expression also serves as survival cues in ways similar to those above. Creativity isn’t a direct requirement for reproductive fitness, but an indicator of the reproductive fitness of the individual. Creativity also implies problem solving ability that is helpful in natural selection and the resource sharing dynamics of reproduction.

From another angle, art represents an external reflection of the mind of the artist. While the rockstar seeks to proclaim uniqueness through personal adornment and external displays of wealth, the artist makes a de facto declaration of intellectual uniqueness with each piece of art produced. As we’ll see in the next section, uniqueness for the sake of uniqueness is an underlying them in evolutionary psychology. The mind has adapted selection preferences based on uniqueness cues to proliferate DNA diversity.

The value derived from the assertion of individual difference varies greatly within the realm of the artist. Picasso created an entire category of painting, attracted legions of women, and died with an estate valued in the billions. On the other hand, Bob Ross attempted to show how easy it was for anyone to duplicate the art he produced and his enduring legacy is his hair. The Artist’s allure comes from the implicit assertion that he is creating something nobody else can create.

Your girlfriend wants to cheat on you with an artist because he proves he can produce something no other man is capable of producing.


How does an average guy like me become the number one lover-man in his particular postal district?” Rob Gordon (played by John Cusack) in “High Fidelity”

If you’ve been paying close attention, you’ll no doubt deduce that the only category left for me to boldly insert myself into is that of the guy with the foreign accent. Most of my readers probably have the same accent, in which case that alone is a stretch. The important thing here is that it’s all relative. When I lived in Alaska, I was the kid from Seattle. When I moved to Oregon, I was the kid from Alaska. When I moved back to Seattle, I was the kid from Oregon. When I moved to Austin, I was the guy from Seattle. When I moved to Panama, I was the guy from Seattle again. When I sail into your town, there’s only one certainty… I’ll be the guy that’s new to everyone… If I’m in the right mood that will equate to novelty. Don’t worry, I’m not there to steal your girl.

Differences in accents imply genetic variance through outside groups. This made complete sense in the living conditions of our ancestors. In the small groups of people that people saw every day and even the tribes with upper limits around 150, inbreeding was a problem by default. Any indicator of genetic variance is hugely valuable. Language, eye color, skin color, and hair color all come into play. The specifics aren’t as important as the overall cue of standing out.

The answer to the High Fidelity quote above is difficult to answer correctly and difficult to reproduce. It’s much easier to become the number one lover-man in someone else’s particular postal district.

Your girlfriend wants to cheat on you with me because nomadic strangers represent the ultimate opportunity for genetic diversity.

No offense to Antonio Banderas, but your girlfriend doesn’t have a crush on him for his accent or his looks per se. Her mind is biologically compelled to provide selection preference to men with genes that vary significantly from hers for reproductive success. Don’t feel bad about it… It’s nothing personal… It’s for the children. Unfortunately, they might be someone else’s.

Why She Won’t Tell You About It

I briefly discussed this above, but I’ll recap it again. If you think your girl is amazing and adorable and madly in love with you, she probably is. Her emotional attachment to you and conscious appreciation of you aren’t in question. I mean sure, if there are problems in your relationship, all of these scenarios are much more likely to occur. They’re also much more likely to occur if you’re not attractive.

The things I’m talking about are impulse level reactions. She doesn’t have an evolved, runaway train necessity to cheat on you. However, she is genetically predisposed to not only reproduce, but also to reproduce with the highest quality DNA possessing male she can get her… um… hands… on.

Here’s another potentially related issue (Translation – another rub): The man with the best DNA is not always the same as the man best suited to contribute resources and/or invest time and resources into raising children. These cases can get tricky because in this case, it’s in the best interest of her DNA to reproduce with someone different than the person she’s in a relationship. Yes, this is code for… If she cheats on you, it may be in her best interest for you not to find out.

Your girlfriend won’t tell you she wants to cheat on you because she doesn’t consciously want to cheat on you and/or if she does cheat on you, she still wants to utilize the dependability and resources you provide.

Yes, the “but” that follows “I ain’t sayin’ she’s a gold digger,” is sometimes a big one.

So What? Who Cares?

As it pertains to my aims on this site, the implications of environmental psychology (EP) run deep. In this introductory expose on my new-found crush for evolutionary psychology, I picked something that all guys feel and wonder about directly. I asked the question from the man’s perspective in large part because there is no real equivalent to Cosmopoliltian and its ilk for men. Wait… did I just call Cosmo a good thing? That wasn’t my intent. The point is that it’s culturally acceptable for women to have public conversations about guys all day long, but guys are supposed to talk about everything in secret.

Did you know that most murders are committed by men in circumstances surrounding reproductive selection (sex)? As it turns out, murder is also an evolved psychological response to sexual selection. Seriously… this stuff goes deep, involves serious subjects, and connects everything.

The more immediate implications are that morals, culture, and society are artificial layers painted over our true nature. Whether that’s good or bad is a matter of perspective. Lifestyle design is about constructing the life that best allows you to express your best self. If you’re stifled by cultural assumptions, socialization, and a framework of rules based on the brushed on facade of society, your personal lifestyle design project will fail.

I stumbled on EP in research following up my articles about The Bigotry of Nationalism and The Curious Virtuosity of Ignorance. Since then I’ve been reading books on it at the exclusion of almost everything else. That has lead to a zillion little questions that have been rattling around in the bank of my mind being answered and explained. It has seriously re-framed my view of the world. As someone who’s pretty diligent about examining all the options, that wasn’t something I expected.

Related Stuff I’m Working On

I’ve been noticing quite a few other people and even entire genres that draw much of their underlying theories from EP. I’m working on articles about:

  • How Neil Strauss, Author of The Game; Erik von Markovik (a.k.a. Mystery), creator/star of VH1′s “The Pickup Artist” and author of The Mystery Method: How to Get Beautiful Women Into Bed; and the rest of the “pickup community” base almost all of their techniques on evolutionary psychology.
  • The Steve Pavlina – Evolutionary Psychology connection

In addition, I’m working on pushing evolutionary psychology farther into the applied areas of:

If you made it this far you have to be looking for an angle on lifestyle design that’s far from the all too common “5 Ways to Conquer Your Fear of the Dark” style blogs out there. Here’s where to Get Free Updates. Since you probably took the musician section above seriously and now refuse to pay attention to anyone without fans, here’s what some respectable people have said about/to me:

  • Lifestyle designers, entrepreneurs: Follow [Andrew] & read his blog… It’s seriously smart.” -David Walsh of muselife.com
  • I really, really, really like (non-sexually) this guy = @evolvify check Andrew’s blog.” -Derek Johanson (Also listed me in his Favorite Blogs of the Moment)
  • Why you should check this blog out: Andrew livesaboard a sailboat, runs an ad agency and is on a quest to explore moreof planet earth than anyone in history using only human, wind, andsolar power.” -Corbett Barr (from 44 Creative and Adventurous Bloggers You Should Know)
  • My fiance doesn’t want me to hang out with you anymore.” -An Ex-Girlfriend 

A closer look at the guys »