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.”