My ex just started dating a female friend of his. When we were together, I always worried about the chemistry I felt they had, and it hurts that they got together right after our breakup. Does this mean he's always had feelings for her? Does it cheapen our entire relationship?

--Bummed

"I only have eyes for you" is sometimes actually true, like when two people in a relationship are being held hostage together in the trunk of a car.

Beyond small-space kidnappings, the reality is typically more like: "I only have eyes for you. And you. And you. And, hey, is that your sister?" We're each attracted to a whole crop of people. However, attraction doesn't necessarily lead to action, at least for those of us who have a psychological moat holding us back. It's largely two things that keep us from sneaking out and having sex with the hot neighbor: love for the person we're with and a personality trait called conscientiousness.

Conscientiousness, which has a bunch of letters in common with "conscience," is defined by social and personality psychologist Brent Roberts and his colleagues as "the propensity to follow socially prescribed norms for impulse control, to be goal directed, to plan, and to be able to delay gratification."

A person with a solid helping of conscientiousness cares about the impact of their behavior on other people. However, being attracted to somebody happens automatically; it isn't a feeling we can decline like a questionable package. So, conscientiousness does not prevent a wandering eye, just wandering sex parts that get busy in its wake.

Even people high in conscientiousness probably have a mental file drawer of potential partners -- "backup mates" -- even when they have a partner they love. Research on backup mates by evolutionary psychologists Joshua Duntley and David Buss suggests we evolved to have these in mind, at least subconsciously, to shorten the reproductively costly breaks between being dumped or having a partner die on us and landing their replacement.

Ultimately, you have no control over another person's feelings. What you can control are your choices, using love (plus physical attraction) and conscientiousness as a guideline for whether to stay or move on. Regarding conscientiousness: A man whose actions day to day suggest he's ethical is a man who's less likely to end up in bed with somebody else while he's still in a relationship with you. As for love and attraction, a man who seems to have serious hots for you, sexually and as a person, is more likely to stick around and keep loving you. You'll still probably catch him glancing at sparkly ladies at parties, but try to keep in mind that window-shopping is not the same thing as robbing the store. (Breakfast at Tiffany's; lunch at Rikers!)

For pages and pages of "science-help" from me, buy my latest book, "Unf*ckology: A Field Guide to Living with Guts and Confidence." It lays out the PROCESS of transforming to live w/confidence.

My boyfriend and I broke up two years ago, and I guess I'm not over him. I'm not still pining for my ex, but I find myself comparing every guy I date to him. How do I get him out of my head?

--Haunted

When you're looking for love, it's good to avoid wearing distracting jewelry, like an ex-boyfriend-shaped anvil on a chain around your neck.

But maybe you don't have the problem you think you do: not being over your ex. After all, you say you aren't pining over the guy. Consider that we don't make judgments by pulling them out of thin air. We need comparisons -- to things, people, or prices -- as a starting point. An example of this comes from economic psychology. Psychologists Daniel Kahneman and Amos Tversky observed that the price a person is initially exposed to serves as an "anchor," influencing decisions they subsequently make. For example, Kahneman writes that upon mention of a charitable contribution of $5, research participants were willing to contribute $20, on average. "When the anchor was a rather extravagant $400, the willingness to pay rose to an average of $143."

However, when we have no reference point, no starting point for comparison, judgments we make tend to be all over the place, not refined or useful. For example, "Is ice cream good?" versus the comparison, "Is ice cream better than gluten-free kale cookies sweetened with artisanal tree rot?"

Chances are you're using your ex as a reference point to recognize the qualities you do and don't want in men you encounter. Consider divorcing these qualities from the man by listing them, perhaps in a note on your phone you can periodically reflect on. It might not entirely remove him from your mind, but it could make you feel less haunted by him, less like you aren't over him. Remember, "Objects in the rearview mirror..." um, look much closer when you rope them to your mental hood like a deer.

For pages and pages of "science-help" from me, buy my latest book, "Unf*ckology: A Field Guide to Living with Guts and Confidence." It lays out the PROCESS of transforming to live w/confidence.

I'm a gay man. I was in a relationship with my ex for about three years. We're on good terms and hang out as friends. He recently started dating a guy who looks like my long-lost twin (except he's got about 40 pounds on me). Our mutual friends find this creepy and weird, and I have to say, I do, too.

--Disturbed

When two people break up, there's often the inevitable, "It's not you..." but you don't expect, "It's not you; it's you...with more of a thing for beer, fried foods, and cake."

This sort of thing can seem seriously creepy, until you drop in on a behavioral genetics researcher like Nancy Segal. Research by Segal and others on identical twins separated at birth (sometimes by a hospital mix-up) and raised apart suggests that many of our behaviors and preferences are genetically driven. For example, Segal told me "most behaviors have a 50% genetic effect." There's an interplay between genes and environment that can shake things up a bit, but if Mommy likes hot food and dark-haired men, there's a good chance her daughter (who shares approximately 50% of her DNA) will also be thumbs up for Sergio and Sriracha.

The power of genes in driving behavior and preferences is reflected in Oskar and Jack, separated-at-birth identical twins Segal studied. When they met as adults, they discovered they both wrapped tape around pens and pencils to get a better grip, read books from back to front, and flushed toilets before using them as well as afterward. Sure, these could be wild coincidences, but they're most likely expressions of personality traits, which are substantially driven by genetics. For example, Segal explains in "Indivisible by Two: Lives of Extraordinary Twins" that "both Jack and Oskar were sensitive to germs," so their shared "penchant" for the double flush "is understandable."

We might not see situations like yours often simply because there's a gap between the features and traits we're most attracted to and those available to us in people around us. Accordingly, it is possible that neither you nor the new guy entirely reflects your ex's mate preferences, but your ex missed you and came as close as he could to replacing you when choosing his next boyfriend. Apparently, he picked him up not at the bar but at Costco, where the products we know and love come in more generous packages: "Dumpster-sized," "Grand Canyon-sized," and "black hole-sized extra value pack."

For pages and pages of "science-help" from me, buy my latest book, "Unf*ckology: A Field Guide to Living with Guts and Confidence." It lays out the PROCESS of transforming to live w/confidence.

I'm a 30-year-old woman in a new relationship with a really great guy. I haven't been very lucky in romance, and in the past, every time I met someone I really liked, I ended up getting the rug pulled out from under me and getting dumped when I thought things were going great. This has left me with some raging insecurities. How can I calm down so I won't get so freaked out that I sabotage the relationship?

--Panicky

It's good to let your partner know you don't take him for granted, though ideally not by waking up every morning all excited he's (still) there: "Wow, can't believe you didn't sneak out, fake your death, and move to Belize!"

The Stoic philosopher Epictetus said something along the lines of, "It is not events that disturb us but the views we take of them." In other words, it is not what happens to us that makes us feel bad but our interpretation of it. Chances are your interpretation is that it would be HORRIBLE if you were to get dumped again. Psychologist Albert Ellis calls this "catastrophizing": engaging in irrational, overblown, drama llama thinking that only serves to make us more miserable. Rational thought, however, is the face-slap out of hysteria that we used to see in old movies. An example of the rational approach: There are "HORRIBLE" things in the world, like being eaten alive by a family of bears. But let's be honest: Being dumped is merely a miserable experience you'd prefer to avoid. You will survive.

Research by psychologist Lauren C. Howe suggests a person's interpretation of their breakup is key to their ability to recover from it. She finds that people who cast their breakup as a learning experience, viewing it as an opportunity for personal growth and better relationships in the future, are less chewed up by romantic rejection and less likely to suffer "lasting damage" in its wake. Sure, as Ellis says, we all "prefer" to avoid breakups and other painful experiences. Unfortunately, "experience is the best teacher" does not include the experience of being clonked over the head by a chunk of wisdom that falls out of a passing plane along with a child's car seat and a gift-wrapped blender.

For pages and pages of "science-help" from me, buy my latest book, "Unf*ckology: A Field Guide to Living with Guts and Confidence." It lays out the PROCESS of transforming to live w/confidence.

I'm a single woman. I'd love to get into a relationship. Often, when I'm at a bar, I see a guy I'd like to chat up, but I won't even approach because I don't know what to say. Are there some pickup lines men love to hear?

--Looking

There are a number of lines men would love to hear from a woman -- among them, "I've really enjoyed my drink, and now I'd like to enjoy you" and, "Don't you have a tattoo I should be licking?

However, there's what men love to hear, and there's what's actually effective when you're seeking a relationship that lasts long enough for you to learn to pronounce the guy's name: "Is that Fred, like 'Fred'?"

Evolutionary psychologist Maryanne Fisher and her colleagues researched which pickup lines, used by women on men, are most effective. "Effectiveness," Fisher writes, "was defined as success in securing a phone number or agreeing to meet again."

Pickup lines fall into three categories: "direct," "innocuous," and "flippant." "Direct lines clearly convey interest" through unambiguous requests and flattering remarks, explains Fisher -- for example: "Want to have a drink together?" "You have really nice eyes," and "Can I have your number?"

Innocuous lines, on the other hand, "hide the intention of the speaker and act more as conversation starters." Examples include: "Can you recommend a good drink?" "I've seen you before; do you work here?" and "Where did you get that tattoo? Did it hurt?"

Flippant lines involve humor -- or, um, attempts at it, like an example Fisher references from previous research: "Can I get a picture of you so I can show Santa what I want for Christmas?" Another flippant charmer: "Is that really your hair?"

Fisher explains that, like innocuous lines, "flippant lines are theorized to protect the user from rejection, as they can disguise a failed attempt as a simple question or a joke." Unfortunately, both flippant and innocuous lines also seem to "protect" the user's target from knowing that the purveyor is interested.

Fisher's research, like previous research, found that men preferred direct pickup lines to the innocuous and flippant ones. This isn't surprising. Men tend to be bad at picking up hints, and many are terrified of overestimating a woman's interest and waking up to their name hashtagged with #MeToo. When a woman uses a direct pickup line, and especially when she spreads additional direct lines around in conversation, she's telling a guy she's interested in seeing more of him, as opposed to seeing whether she should Mace him.

Unfortunately, there's some nuance to the Fisher team's findings -- what might be called (sorry!) beauty inequality. Direct pickup lines were preferred by men when the women using them were really attractive. Direct lines were less effective for less attractive women -- except when they were scantily clad.

Also, men will tell you they love when women ask them out. (Of course they do. It's like they're standing on a dock fishing when, out of nowhere, a plate of perfectly cooked salmon flies out of the water and lands on the bench beside them.) Unfortunately, evolutionary research suggests that for women, overt pursuit of men, like asking them out, is a risky strategy.

The research comes out of what evolutionary biologist Robert Trivers, in 1972, called "parental investment theory": Because women have a high potential cost from any sex act -- pregnancy and a kid to feed -- they evolved to be the choosier sex, and men coevolved to expect female aloofness, especially from women with high "mate value." When women seem too eager, men tend to devalue them, seeing them as desperate or just hookup material.

Synthesizing Fisher and Trivers, my takeaway is that you should be unambiguous in showing interest in a guy -- and ideally, repeatedly unambiguous. Use flattering remarks to make your interest plain, but stop short of highly sexual remarks, which are likely to mark you as hookup fodder, or asking a guy out. Your goal should be flattering a guy into understanding that you're interested in him. This allows you to see whether he's got real interest in you -- enough for him to lay his ego on the line and hit you up for your number.

Do this regularly -- being flirtatiously forward -- and you should come to understand that you have the power to summon men into your life. Maybe not all the men you want, but more than you would have thought. This, in turn, should keep you from going all desperate -- to the point where you seek out men you'd previously, um, overlooked...like that construction worker: "Hey, you! You in the hard hat! You had me at 'Those boobs real?'"

For pages and pages of "science-help" from me, buy my latest book, "Unf*ckology: A Field Guide to Living with Guts and Confidence." It lays out the PROCESS of transforming to live w/confidence.

This guy recently moved into my apartment building, and we seem to have a spark. I'd like to go out with him. However, because we live in the same building, this might be a bad idea. If it goes badly, things could get really awkward or even horrible. Should I just try to forget about him?

--Tempted

Let's just say this has some negative potential -- along the lines of throwing back a bottle of pinot noir all by yourself and then deciding to cut your bangs at 1 a.m.

Though going for it with this guy could go seriously wrong, there's also the potential for it to go seriously right. Risk can be a path to reward (whereas avoiding it is unlikely to lead to a shiny new boyfriend suddenly sliding down your chimney, Santa-style).

To figure out whether you can afford the risk, apply a concept from economic psychology: "Risk tolerance." This is a term for how much stomach somebody has for the possible loss of an investment they make -- all their dollars leaping out of it and swan-diving en masse into a toilet, with the final straggling dollar kicking the flusher on its way down.

Essential to determining your risk tolerance is figuring out the possible costs if a thing between you and this guy goes all crashy-burn. For example, there could be financial costs if you end up needing to move. You should also factor in your tolerance for drama, like embarrassing public encounters with a Mr. Romantic turned Mr. Should Be In A Jacket With A Lotta Buckles. Also consider your fiscal and emotional fortitude for what psychologists Joseph Luft and Harrington Ingham called "unknown unknowns": crazy stuff most of us just wouldn't imagine happening, like much of the adult world getting grounded by the government.

If you decide to give it a go with him, consider taking things slowly. This is generally prudent but especially so when you could have a stalker who doesn't have to follow you home because he lives there, too. If you're like me, you love to make an interesting entrance, but that probably doesn't include getting into your apartment via rope ladder.

For pages and pages of "science-help" from me, buy my latest book, "Unf*ckology: A Field Guide to Living with Guts and Confidence." It lays out the PROCESS of transforming to live w/confidence.

I'm a 20-year-old girl with a big crush on my very cute boy co-worker. Day after day, week after week, I want to invite him out for drinks, but then I chicken out. I ask myself all the usual questions, like, "What if he says no, and work gets weird?" and, "What if he tells the boss, and then I get fired?"

--Procrastinating Endlessly

You'd be asking him to go for drinks, not asking him to straddle you in the staff restroom.

Unless there's a policy forbidding co-workers from dating, asking this guy out should not lead to you and your job being forced to part company. Surely, you know that. Chances are your goal of asking the guy out is getting tangled up in your groping around for an excuse to avoid doing it.

This is understandable. The prospect of failing at a goal -- especially a romantic goal -- is stressful, but there's a way to make failed efforts take less of a bite out of you. It turns out that in goal pursuit, there's safety in numbers -- in simultaneously pursuing a flock of goals rather than just one goal at a time. A single bird can get shot down, but it's hard to shoot down a whole flock at once unless your weapon of choice is an alien death ray.

Consider replacing being goal-oriented with the broader approach: being goal systems-oriented. A goal is simply a result you're trying for -- a single result, like "get Joe Shelfstocker to go out with me." The singularity is the problem. If Joe turns you down, you've failed at your goal. Hard out.

Goal systems are more forgiving. While a goal is a lone target -- win or lose, all or nothing -- a goal system, as explained by social psychologist Arie Kruglanski, is a network of "interconnected goals." A goal system would be, "Work toward having love in my life." This goal system would be the home of your goal of getting a date with the guy, but it would take up residence with a bunch of brother, sister, and cousin goals, such as: Work on building up confidence. Get a cuter haircut. Go out more.

When you fail at a single goal, if it's simply one of many in your goal system, you've got cushioning. Your failure is just a momentary bummer within a world of to-dos, at least some of which you'll manage to pull off. Being goal-system-driven gives you the emotional air bag to go forward all "carpe diem!" -- "seize the day!" -- instead of downshifting to "cogit ergo spud": "I think I'll act like a potato" (um, loosely translated).

For pages and pages of "science-help" from me, buy my latest book, "Unf*ckology: A Field Guide to Living with Guts and Confidence." It lays out the PROCESS of transforming to live w/confidence.