Does one orgasm equal two cheeseburgers?             

Eric Barker, Barking Up The Wrong Tree, 07/17/12

Approximately. When you measure the release of dopamine that food, sex and drugs cause you can roughly quantify the amount of pleasure each delivers. (Via Frontline, slides by Richard Rawson:請至原網頁參考統計圖表)

Methamphetamine effects the centers of the brain that control judgment, control reward, and control memory. The most important one probably are the reward centers of the brain. When, when that part of the brain is stimulated dopamine’s released, and you experience that as pleasure. Under normal circumstances those responses occur for naturally occurring rewarding events.

Similarly if you put a rat, a male rate in a box and you give him access to a receptive female, and you allow them to have sex, at the point where they experience orgasm you get a huge release of dopamine. You see an increase of about 200 units. This rush is what feels good and what is experienced is pleasure. And this slide of course illustrates the principle that one orgasm equals two cheeseburgers.

Now drugs of abuse release dopamine. Alcohol, for example, produced a release of dopamine from about 100 units to about 200, You get a similar magnitude of an effect with nicotine. Cocaine produces a huge release of dopamine, from 100 units to about 350 units, however the mother of them all is methamphetamine. Methamphetamine you get a release from the base level to about 1250 units. A tremendous increase of dopamine. This produces an extreme peak of euphoria that people describe as something like they’ve never experienced and they probably never have experienced before because the brain really isn’t made to do this. And that’s why people will be attracted to it and want to take it over and over and over again. They want to produce that response.

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The science of sex: 4 harsh truths about dating and mating       

Look away if you want to stay a naive romantic

Eric Barker, Barking Up The Wrong Tree, 09/12/14

To make the best decisions, we cannot delude ourselves.

I've posted many studies offering hope and inspiration but to be honest and fair, we also need to look at facts about people many like to deny.

And that's where the science of sex comes in.

If you wish to retain illusions that the realm of sex and relationships is pure as the driven snow or that outside of physical dimensions there are no fundamental differences between men and women, turn back now as I am about to open a large can of peer-reviewed whoop-ass.

Naive romantics, I warn you one last time:

ABANDON ALL HOPE YE WHO ENTER HERE

So what are some harsh truths that the science of sex has shown us?

1) Those things we say we hate actually make us more attracted to people.

When someone plays hot-cold, keeps you guessing, makes you constantly uncertain?

Yeah, that makes you even more attracted:

Participants in the uncertain condition were most attracted to the men — even more attracted than were participants who were told that the men liked them a lot. Uncertain participants reported thinking about the men the most, and this increased their attraction toward the men. [Psychological Science]

Playing hard to get? It works.

Had it up to here with narcissists? No, we haven't because they really are more attractive.

You know what we like about them the most?

The worst parts — their entitlement and exploitativeness:

…narcissism leads to popularity at first sight. Second, the aspects of narcissism that are most maladaptive in the long run (exploitativeness/entitlement) proved to be most attractive at zero acquaintance. [Journal of Personality and Social Psychology]

2) Yes, guys are pretty shallow.

The stereotypes are true: men want sex more than women and, yeah, guys are more likely to hit on girls with big boobs.

(Most of us didn't need scientific studies for that but, hey, I'm thorough.)

Studies show that often the main reason men kiss is to progress toward sex. The main reason men cuddle after sex is… to get more sex:

…females were more likely to engage in post-coital behaviors related to bonding with both short- and long-term partners, whereas males were more likely to engage in ones that were extrinsically rewarding or increased the likelihood of further coital acts. [Journal of Sex Research]

What determines how much a guy spends on an engagement ring? The younger the woman, the more he spends:

The total spent on rings was positively correlated to the annual incomes of both men and women but negatively correlated to women's ages. [The Consuming Instinct: What Juicy Burgers, Ferraris, Pornography, and Gift Giving Reveal About Human Nature]

Research shows, if men didn't need to impress women, they probably wouldn't leave the couch:

The results show that if there were no returns to career choices in the marriage market, men would tend to work less, study less, and choose blue‐collar jobs over white‐collar jobs. [Journal of Human Capital]

Statistics show men are about as likely to cheat on their wives as they are to experience a flight delay.

Not dark enough for you?

Guys are more likely to cheat when their wives are pregnant:

Controlling for marital dissatisfaction and demographic variables, infidelity was predicted by greater neuroticism and lower religiosity; wives' pregnancy also increased the risk of infidelity for husbands. [Journal of Family Psychology]

3) Women can be quite dastardly too.

The science of sex tells us that the romantic comedies lie. Sex is an area where nice guys do finish last:

In one survey of men, Trapnell and Meston (1996) found that nice guys who were modest, agreeable, and unselfish were disadvantaged in sexual relationships. Men who were manipulative, arrogant, calculating, and sly were more sexually active and had a greater variety of sexual experiences and a greater number of sex partners. [Journal of Sex and Marital Therapy]

Women are very often attracted to bad boys like James Bond. In fact, research shows young women sometimes prefer out-and-out jerks:

In the end, young women may continue to claim that they find certain qualities in a "good guy" nice guy as highly desirable and that they want to be in a committed relationship with one man as their ultimate goal, but, at the same time, they seem content to spend "the meantime and in-between-time" going out with fun/sexy guys who may or may not turn into "jerks." [Sex Roles]

Happy guys, it seems, can be a turn-off:

…happiness was the most attractive female emotion expression, and one of the least attractive in males. [Emotion]

What do studies say can make a man more attractive? Among other things, a flashy car and throwing money around. Yes, that works.

Women find married men more attractive than single men:

…a group of women again rated photographs of men for attractiveness. The photos were accompanied by short descriptions, and when the men were described as "married," women's ratings of them went up. [Connected]

And they find sexist men more appealing than non-sexist men, too. Wow.

4) Little of the above will be changing anytime soon.

This is the science of sex, not the culture of it. Most, if not all, of these things are true around the world.

In a study of over 1000 participants in three dozen cultures it was consistently found that men are focused on looks and women on status:

Several standard sex differences replicated across cultures, including women's greater valuation of social status and men's greater valuation of physical attractiveness. [Personality and Individual Differences]

But we grow out of it, right? Nope.

Our tastes do not mature as we get older:

Findings suggest that although emerging adults believe that their peers' mating desires change systematically over time, emerging adults' self-reported mating desires vary little with age. [Evolutionary Psychology]

In fact, when men and women are in nursing homes, the guys are still looking for hot younger women and the ladies are still interested in men of high status:

Across the life span, men sought physical attractiveness and offered status-related information more than women; women were more selective than men and sought status more than men. [Psychology and Aging]

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More from Barking Up The Wrong Tree...

      What are the four things that kill relationships?

      Does one orgasm equal two cheeseburgers?

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http://theweek.com/article/index/266665/the-science-of-sex-4-harsh-truths-about-dating-and-mating

10 Stubborn Sex Myths That Just Won't Die, Debunked     

Adam Dachis, 02/14/14

Perhaps you've heard that size matters, women are naturally more bisexual than men, or that tantric sex means everlasting orgasms. The fact is, none of these things are quite true. Sex has been around forever, but we're just starting to understand it. Today we're debunking 10 of the most common sex myths to set the record straight.

I like sex as much as the next guy, but I'm not going to pretend for a second that I'm an expert. To help get to the bottom of each myth on our list, I requested a little help from some top sexologists: Dr. Debby Herbenick (research scientist at Indiana University, sexual health educator at The Kinsey Institute, and author multiple books including Sex Made Easy), Dr. Lindsey Doe (doctor of sexual health and host of Sexplanations), and Dr. Amy Marsh (clinical sexologist and sex counselor). Let's get down to business and find out what we do know.

Myth 1: Penis Size Matters

Men seem to care a lot about the size and shape of their penises, but do women -- or even other men? And how much does it actually affect performance in the bedroom? Some argue larger penises can create a more intense orgasm during penetrative sex. Others presume that men with smaller members make up the difference with added effort. So is it all a wash in the end? Debby argues it can depend on the person but ultimately has more to do with a psychological connection than anything else:

To some people, size does matter. They may wish their partner were longer or shorter or thinner or thicker. The bottom line, however, is that research consistently finds that sexual satisfaction is more influenced by psychological connection, intimacy, and relationship satisfaction -- not just the size or shape of a person's genitals. In our study of more than 1600 men, we found the average erect length was about 5.6 inches, with most men hovering around that average. How two people connect through sex is typically more important than the size of the parts, however.

Amy agrees, and notes some men might underestimate what they've got and that there's no one-size-fits-all when it comes to genitalia:

Size matters to those who let it matter, and that includes men and women. People have and inflict too much body shame about genitals. Some even worry when they are "average." For example, men who look downward at their penises (or who have belly fat) may see them as smaller than they actually are. Sometimes a larger penis may be "too large" for oral sex, but just right for penetration. Or a smaller penis may feel just right for oral sex, as it can be taken more completely into the mouth. Motion, rapport, depth of intimacy, lovemaking skills, and/or positions often have more to do with partner satisfaction than size.

So what should you do if you're unhappy with the size of your package? Stop worrying so much about what you're working with -- whether too large, too small, or too average -- and figure out how you can use it to please your partner. Any partner worth your time won't reject you solely based on the size of your penis, and if they really want something different from time to time you can supplement your sexual regimen with toys.

On the other side of the issue, if you have a partner who struggles with his size, be supportive. If the sex is good, let him know. When it isn't, make suggestions that will increase your pleasure. It may be his insecurity, but good partners should help each other.

Myth 2: Men and Women Reach Their Sexual Peak at the Same Time

When do men and women reach their sexual peak? Some believe men get there sooner in their late teens and early twenties while women experience similar results a little later in life. Debby believe there's no real way to know for sure:

I hear this all the time and everyone means something different (frequency of sex, enjoyment of sex, ease of orgasm, etc). But however I look at it, I can't make full sense of it. Do men have easier erections at 18 than age 70? Sure, but the sex may be more meaningful and satisfying at 70 than 18 (generally speaking). Enjoyable sex can happen at any age. It's rarely all physical or all emotional. Sex is this fascinating place where our bodies and emotions and past experiences and future hopes collide, and that can result in something pretty spectacular at any age. If you think you've reached your peak, forget it. The best may still be yet to come.

The same advice goes for those who haven't reached their peak. You shouldn't worry about it. So long as you're comfortable with who you are, understand your own body, and remain reasonably open to new experiences, you should have no problem enjoying a satisfying sex life. Whether a "peak" comes or not doesn't matter much if you're having a good time.

Myth 3: Most Women Can Achieve Orgasm From Vaginal Sex Alone

Wouldn't it be easy if orgasms resulted from simply following instructions? Just insert Tab A into Slot B, move it around for a while, and enjoy. Perhaps because it more often works that way for men, this unfortunate myth arose for women. Most don't achieve orgasm from vaginal sex alone even though it's possible -- anatomically speaking. Debby explains:

It's not that simple to determine who "can" have an orgasm from a certain type of sex (after all, whether someone has an orgasm during sex depends on more than just their ability, but also on how they feel about their partner, their partner's technique, etc). And when women have orgasms from penile-vaginal intercourse, it's not always clear-cut how exactly the orgasm came to be. After all, the clitoris has inside parts and outside parts and intercourse stimulates both. The vagina, including the G-spot area, is also stimulated during intercourse as are nerves around the cervix, including the vagus nerve, which is one pathway to orgasm.

Continuing on that theme, Amy notes that orgasms can occur in all sorts of ways:

Human beings can achieve orgasm in all kinds of ways. Mary Roach, author of Bonk, found a woman who could think herself to orgasm and another who orgasmed while brushing her teeth. However, the persistent emphasis on vaginal orgasm at the expense of clitoral stimulation is incredibly damaging. It's more more accurate to say that the "majority of women" will need some kind of consistent clitoral stimulation in order to experience orgasm. And we should also remember what sex researcher Mary Jane Sherfey asserted as long ago as 1966: "the clitoris is not just the small protuberance at the anterior end of the vulva."

So how do most women achieve orgasm? Debby breaks it down:

What we do know very clearly is that women and men experience orgasm through diverse sexual behaviors. According to data from our 2009 National Survey of Sexual Health and Behavior, most women (about 2/3) have orgasms when they have sex, and this could be from vaginal, clitoral, breast or other kinds of stimulation. And yet in another study, nearly 1/5 of women reported preferring oral sex in order to have an orgasm.

We can hash out statistics all day, but ultimately we still have a problem: orgasms are less common for women than men. For women who have difficulty achieving orgasm, Debbie recommends reading Sex Made Easy and Becoming Orgasmic for a little help.

Myth 4: Men Can't Have Multiple Orgasms

Men are known for shutting down and going to sleep post-ejaculation (for biological reasons), so the idea of multiple orgasms sounds almost ridiculous to many people. That said, it happens. Some men can do it naturally, but most have to work pretty hard. Amy explains:

Men can, but it's usually learned skill involving Taoist or Tantric techniques which include breath control and making a distinction between ejaculation and orgasm. You can find these techniques in books like Mantak Chia and Douglas Abram's account of Taoist sexual practices, The Multi-Orgasmic Man. It's interesting to note that sex researchers William Hartman and Marilyn Fithian said that 12% of men they'd studied were reporting multiple orgasms.

Debby notes that there are some men who can ejaculate repeatedly, however:

There are the rare men who can ejaculate over and over again, kind of how many women can orgasm repeatedly. Why this differences occurs is not well understood – and there's no sense it can be taught (these men seem to have some physical differences from other men).

While some men can ejaculate more than once, most can't and never will. That said, men looking for more than a single orgasm can teach themselves to achieve them.

Myth 5: Women Are Naturally More Bisexual

Females are generally considered a more fluid gender in regards to sex, but does that mean men are less likely to be bisexual? According to Lindsay, the answer is pretty straightforward:

Nope. While there is no consistent data on how many people identify as bisexual, we do see stats where there are twice as many bisexual men as there are women. Sexual orientation is natural, and no more for one gender than others; it may be more socially acceptable and therefore easier for women to express more flexibility or fluidity with their sexualities but this does not equate to their identities nor does it exclude the men who experience attraction for their sex and other sexes.

Debby concurs, citing a few studies of her own:

Sizable minorities of women and men have had sex with same-sex partners. For example, in one of our national studies, we found about 15% of women had had oral sex with another woman and about 11% of men had had oral sex with another man. Far fewer women and men identify as gay or lesbian or bisexual. Research suggests that both women and men may be somewhat "fluid" in their sexual feelings and behaviors.

Why is this myth so prevalent? It might have to do with higher amounts of "lesbian" pornography aimed at straight men, or a perceived cultural preference towards homosexual sex with women rather than men. While a number of factors may have contributed to this misinformation, it all started with a 2005 New York Times article that argued bisexual men do not exist. More recently, that study was finally debunked. Bisexual men have known this for years that they exist, but now science is finally backing them up. Tell your friends!

Myth 6: Tantric Sex Means Orgasming for Hours

Ever since Sting essentially joked that he had eight hours of tantric sex (surprise: he didn't) and the world took him seriously, everyone wanted to get in on the party. Through quite a bit of misinformation, people came to believe that tantric sex essentially meant endless orgasms. In reality, the tantra uses a different (and less commonly accepted) definition of the word. Lindsey explains:

Tantra is a type of sexual intimacy in which partners use eastern techniques to share energy. The Venus Butterfly technique is said to bring about an hour-long orgasm. Talk about needing a nap after sex!? Critics argue that this so-called tantra-induced supergasm is actually confusing orgasm with other stages of arousal, like plateau and resolution. I'm not one to harness someone's orgasmic capabilities or change the meaning of orgasm to them. I will put out there that the longest orgasm measured in the labs was around one minute and it was not the result of tantra.

Debby concurs, and explains that you generally shouldn't even expect to come close to a minute when achieving orgasm:

Orgasms last a matter of seconds, not even minutes. That doesn't mean there aren't ways to experience euphoric feelings similar to the feelings one experiences during orgasm, but that doesn't make it an orgasm. Not even if it comes with a DVD or a how-to manual or a weekend workshop. And that's okay! Tantric sex practices provide people with new ways to have sex, to connect, and to feel closer to other people.

Like Debby says, the tantric sex certainly has its value. Just don't expect to endless erotic bliss and you'll have a better chance of finding satisfaction.

Myth 7: Men Want Casual Sex and Women Want Commitment

As humans, we've tried to narrow down the base desires of men and women in a multitude of categories and then seem to accept these generalizations as fact. But have you ever met people before? They're all really different! Generalizations lead us down a path of misinformation for no good reason, and what kind of sex each gender wants fits well into this category. Debby explains:

There's no easy gender divide. As it turns out, most human beings enjoy sex and most people say their most enjoyable sex occurs in relationships (not surprising given how highly both men and women say connection and intimacy matter to them). Of course, some men and some women prefer casual sex, and most people have tried casual kinds of sex at some point in their lives. Men and women tend to be far more similar than different in terms of the kinds of sex they enjoy (connecting, intimate) and with whom (relationship partner).

So why might women get the reputation of only wanting commitment, even nowadays? Lindsey offers some insight:

When it comes to heterosexual partner selection, women tend to be more picky because they have more at stake, with the potential pregnancy and all. She's also less likely to orgasm -- 35% less likely.

While orgasms aren't always necessary to have a good time, they're often the part of casual sex people are looking for. If women are less likely to have one, that might downplay the desire of casual sex somewhat. That said, infrequent orgasms don't make a person automatically desire commitment. While culture might urge heterosexual women to settle down with a man and encourage young men to sow their wild oats, people don't subscribe to everything they're told. We find our own ways, like what we like, and few of us represent what the world considers normal -- even those of us who try.

Myth 8: Oral and Anal Are Safe Alternatives to Vaginal Sex

Different kinds of sex come with different risks, and so what's a safe activity depends greatly upon how you define safe. Debby explains:

If your only concern is pregnancy risk, then yes – oral sex and anal sex are safer alternatives than vaginal intercourse. However, most people have concerns about more than pregnancy, and should – given that the US has particularly high rates of sexually transmissible infections (STI). STIs can and are passed through oral sex and anal sex. If you're having oral, vaginal, or anal sex, let your healthcare provider know as different kinds of STI testing may be recommended for you (for example, rectal STI testing if you are having receptive anal sex).

Transmission rates for STIs vary based on different practices and so many factors can increase your risk no matter what you do. For example, unprotected oral sex immediately after brushing your teeth, which can cause small tears in the gums, can be riskier than protected vaginal sex. Under the right circumstances, the inverse can be true as well. You always have to assume a reasonable amount of risk when engaging in sexual behavior. Play it safe regardless of the activity and you'll have less to worry about.

Myth 9: Women Don't Watch Porn

To some extent, watching porn is a guy thing because most porn is marketed towards men -- both straight and gay. That said, pornography geared towards women does exist and women do enjoy pornography. Lindsey provides the numbers:

Almost a third of women report having watched porn and more than 10% of men don't. Plus, when researchers study the physiological indicators of porn on the body, men and women respond equally to sexually explicit material. Their groins fill with blood, muscles tense up and for the women, a big myth debunk, they get wet -- so not a guy thing.

So while it isn't only a "guy thing," it causes a bit of a problem in how both genders see and experience sex. Debby explains:

Most mainstream porn is made by men with other men in mind. It's not surprising, then, that most of the sex acts we see in porn are more focused on men's pleasure than women's pleasure. For example, one study found that porn showed disproportionately high rates of anal sex, fellatio, and two-girl-one-guy threesomes. The market is changing a little with more "ethical porn producers" and more female directors, but it's still a largely male audience.

What can you do to make porn an enjoyable part of a relationship? If you want to watch it with your partner, discuss what's suitable for both of you. If you just want to enjoy it alone, bear in mind that what you see isn't necessarily what you'll get. Don't masturbate solely with pornography -- use your imagination as well. Variety keeps things interesting, and prevents one activity from becoming too frequent in your sexual repertoire.

Myth 10: Great Sex Comes Naturally

Does great sex come naturally? If you ask a handful of people you'll get just as many answers because nobody seems to agree. Some people have great chemistry and don't have to work at it. Other people don't have interests that collide in the throes of passion and have to put in more effort. So which is it? Debby explains why it's a mix of both:

Sometimes people have phenomenal chemistry and everything clicks for a night or the first 3 or 6 months they're together. But most great sex takes practice, patience, and a little forgiveness. Great sex takes accepting each other's bodies and your own. For couples in long-term relationships, it sometimes means having sex to please your partner, knowing that another time he or she will have sex to please you (because your desires aren't always in sync). Some sex will be for tension release, other times it's so you can go to sleep, or to feel closer after an argument, or to make a baby, or to feel in love. One of you might fart during sex. One or both of you is bound to have sexual problems at some point. For example, our 2009 NSSHB data show that about 30% of women reported pain the most recent time they had sex and about one-third had difficulty with lubrication. With about 1 in 5 men feeling they come too quickly, and societal pressure for erections as strong and reliable as superheroes, sexual problems and pressures abound.

So with all those problems, what can couples do to keep having great sex throughout their lives? Debby offers some advice:

Great sex takes care. It takes making mistakes and getting over them. One study found that even among satisfied couples who have regular sex, sex was only "very good" about 20-25% of the time and "good" about half of the time. Kind of like your favorite restaurant – sometimes it's amazing but most of the time you just wouldn't want to eat anywhere else. And sometimes it's kind of "meh" but you keep coming back regardless because you know that most of the time it's pretty great.

So don't be greedy. No single thing is amazing every time. Great sex would cease to be great if it didn't vary from time to time.

Remember: We Still Have More to Learn

We've had sex for many, many years, but only recently started studying it. We still have much more to learn. While this posts represents what we know now, things may change in the future. Remember to always keep an open mind and keep learning. Human sexual education still has a long way to go.

A very special thanks goes out to the gracious contributors to this post:

Dr. Debby Herbenick, PhD, research scientist at Indiana University, sexual health educator at The Kinsey Institute, and author of Sex Made Easy.

Dr. Lindsey Doe, doctor of human sexuality, clinical sexologist, and host of Sexplanations.

Dr. Amy Marsh, clinical sexologist and sex counselor.

Images remixed from originals by Leremy and Kesu.

請至原網頁欣賞相關插圖 (not X-rated)

http://afterhours.lifehacker.com/10-stubborn-sex-myths-that-just-wont-die-debunked-by-1522576378

The science of happily ever after           

Susannah Cahalan, 02/03/14

Make a mental list of attributes you’d require in your perfect mate. Do you picture a handsome, tall man, with six figures in the bank, a sharp wit, a sweet sensibility and an Ivy League diploma to round him out?

Well, I have a bridge to sell you.

That’s because in love, as with genies, we only get three wishes, says relationship expert Ty Tashiro. The more traits you pick that are above the average, the lower the statistical odds that you’ll find a match. And three is the tipping point.

Imagine you have a room of 100 men. If you choose mediocrity -- the trifecta of average income, looks and height -- you’ll have, statistically, only 13 suitors out of 100 to choose from. Increase your criteria to an attractive man at least 6-feet tall who makes $87,000, and you’re left with only one.

Add another trait -- funny, kind, even a political affiliation -- and it becomes statistically impossible to find him out of 100 men.

Tashiro, a professor at the Center for Addictions, Personality, and Emotion Research at the University of Maryland, has run the numbers and thinks we’re approaching this whole finding-a-mate thing wrong. He urges singles to be more statistical in their approach to the “irrational” world of dating.

“All this wishing has led to a case of wanting everything and getting nothing,” Tashiro writes in his first book, “The Science of Happily Ever After: What Really Matters in the Quest for Enduring Love” (Harlequin). Dating should be “about learning to weed out the undesirable traits and rethinking our views about what really matters in a romantic partner.”

Our fairy-tale view of romance -- 88 percent of adults believe in soul mates -- has contributed to the fact that although 90 percent of people will marry in their lifetimes, only three in 10 will find enduring love, Tashiro says. (He gets this statistic by adding unhappy marriages and separations to the 50 percent divorce rate).

When finding a long-term partner, don’t waste your wishes, he warns.

So what should be on your list? Keep attractiveness off the table, if you can. Looks are not a predictor of sexual satisfaction, nor do they correlate to happier marriages. In fact, there “is no reliable association between physical attractiveness and relationship satisfaction,” he writes, quoting from his own research.

A study at the University of Tennessee, which recruited 82 newlyweds to rate each other’s attractiveness (to keep it honest they also had the research assistants rate their hotness factor), corroborates his conclusions. What they found was that there was “no relationship between either partner’s level of physical attractiveness and either partner’s relationship satisfaction.” The only significant association found was that the most physically attractive men were least satisfied with their marriages.

In addition, money does not a happy marriage make -- at least over a certain point. Money makes a difference on the low end of the income scale (which has the highest divorce rates in the first 10 years of marriage), but there seem to be “diminishing returns” on happiness in marriage above a financially stable $75,000 a year.

“Once this $75,000 threshold is crossed, there is no significant association between more wealth and higher levels of psychological well-being,” Tashiro writes. “There comes a point when affluence becomes associated with social pressures and social isolation.”

It seems smartest, then, to focus on finding someone who can “help you create a household where basic needs are met and there is a low probability of experiencing economic hardship.”

So what is the best personality indicator for sustaining a loving relationship? The answer is . . . drum roll, please . . . agreeableness, a. k. a. “the nice guy.”

Agreeableness, one of the Big Five personality traits in the Five Factor Model of human psychology -- the others being extroversion, conscientiousness, neuroticism and openness -- describes someone who is “courteous, flexible, trusting, good-natured, cooperative, forgiving, soft-hearted and tolerant.”

Sure, it’s unsexy, but it’s the most reliable sign that your mate is a keeper for the long haul.

One study of 168 couples found that “the best variables for predicting who would stay married, even better than love, expressions of affection or negativity, was responsiveness, which is closely related to the trait of agreeableness,” Tashiro writes.

Plus, agreeable people are often better in bed.

“Men high in agreeableness are not only more likely to be kind, but also more likely to keep the sexual desire alive in relationships,” he writes. They are more giving and often more sensitive, which makes for better between-the-sheets action.

In other words, when looking for marriage material, nice guys should finish first. This is equally true for men looking for women: Niceness trumps all.

If you’re playing the odds, it’s best to invest in a nice mate instead of a hot or filthy rich one.

Even more so, nice guys tend to stay nice. Looks and money do not come with a lifelong guarantee, while personality traits (i.e. those Big Five) tend to stay constant over a lifetime, according to longitudinal studies.

So what is the No. 1 worst trait for relationship sustainability? Sorry, Woody Allen and friends: This one is neuroticism, defined as those prone to anxiety, depression, embarrassment, emotional instability and insecurity.

One study found that neurotic partners were more likely to break up with partners with lower rates of neuroticism “as if neurotics could not stand their good fortune.”

Many other studies have found that neuroticism is the No. 1 predictor of future relationship success -- or lack thereof.

“The only variable that distinguished happily married couples from those who were unhappily married and from the two groups that divorced was contrariness, which is the variable most closely related to the personality trait of neuroticism,” Tashiro writes.

That’s not all. Openness, though a good trait on the surface -- cultivated, cultured, imaginative, original -- makes for a relationship disaster when combined with low levels of conscientiousness. This novelty-seeking mate is almost certain to cheat, he writes.

Unfortunately, because of the magic tricks that love plays on perception, we often don’t see the tell-tale signs.

There’s actually a term for this trend: Researchers call it “positive illusory bias,” when people inflate the positive personality traits and future potential of their mates, compared to outside judges like family, friends and even strangers.

Take this sobering study conducted by John Gottman at the University of Washington. Couples came to the “Love Lab” and were asked to talk for 15 minutes about “continuing disagreements” and “events of the day” as researchers who had never met the couple observed.

Certain behaviors -- like signs of defensiveness or resentment -- were noted. With these details, trained researchers were able to detect whether or not the couple would divorce in 10 years with 90 percent accuracy. In another similar study done at Harvard, even untrained undergraduates were able to guess the couples’ futures based on a 15 minute interaction with an 81 percent accuracy.

While researchers can see clearly, so many of us are blinded by love.

So what are we do to?

To properly fall in love, you need to have sound levels of “liking” and “lusting,” Tashiro writes. It sounds simple, but maintaining both factors is complicated -- especially when you take into account attrition rates.

Like and lust diminish over time, but at different rates. According to studies, liking declines at a rate of 3 percent per year, while lust deteriorates faster at 8 percent per year. Clearly, putting our eggs in the like basket is a much smarter investment strategy, Tashiro says.

Knowing all this -- and most of us should -- doesn’t stop the fact that finding a mate is largely an “irrational” process. Statistics and love are like oil and water, but Tashiro hopes to make the mixture a bit more palatable, especially for those looking for long-term love.

Be clear about our goals, he says. Are we looking for a fling? A marriage? Do we want stability or a hot affair? Once we know this, move on to the traits that we require in a lover. (Remember: No more than three.)

“A grown-up love story should not be a fairy tale or a romantic tragedy, but instead should be approached as a mystery,” he writes. “If the goal is to find the truth in love, to search for love that is real and enduring, then love cannot be left to fate.”

One thing you can do is to take seriously those early red flags, the peccadilloes in our loved ones we’re certain we can change.

“If you choose someone with traits that drive you crazy or make you sad while you’re dating, then those traits will make you crazy or sad for decades to come,” he writes. “So you want to choose well, because what you see is what you get.”

http://nypost.com/2014/02/02/for-real-long-lasting-love-the-no-1-trait-to-seek-is-niceness-expert/