I am almost 50 but look much younger, and I'm noticing that a number of the guys who are pursuing me are in their early 30s. I'm flattered but not really interested, as I want to get married again and I'm thinking that these guys are too young to consider that and probably want to have babies. Am I a magnet for guys with mommy issues? What gives?

--Puzzled

Nothing like rolling up to your guy's band's gig and having everybody be all "Mike, your mom's here!"

As for these young whippersnappers' intentions, chances are the only "aisle" they're looking to walk down with you is the one from the front door to their bedroom in the pizza box graveyard-slash-apartment they share with a bunch of dudebros. Of course, men, just like women, can get to a point where they're ready for cuddlyschmuddlywuddly forever -- which is to say, a relationship. However, evolutionary psychologist David Buss explains that there's strong evidence from a good deal of research that men (who don't have to worry that they'll get pregnant from sex) evolved to "have a greater desire for short-term mating" -- casual sex with a variety of partners.

Buss notes that there are some stumbling blocks for men in short-term mating mode. A major one is "the problem of avoiding commitment." That's where you older but still hot ladies sometimes come in. Older women are less likely to demand a relationship with an age-inappropriate partner. Of course, older women are also likely to be sexually experienced and sexually adventuresome in a way younger women aren't. And, unlike younger women, who are often shy about expressing what they want in bed, older women can stop just short of going all Gunnery Sergeant Hartman: "Faster, you maggot, faster! And 3 millimeters up and a centimeter to the left!"

The thing is, sometimes two people with the most casual of sexual intentions unexpectedly fall for each other. But if you and the young hardbodies can stay in the sex-only lane, your having regular sex might help you take your time getting to know dates with real partner potential for you rather than flying right into bed. Finally -- generally speaking -- there's the obvious plus in sex romps with the young Turks: fewer occasions when the manparts are like papier-mache fruit -- for decorative purposes only.

I'm a woman with a male business partner. He just got a new girlfriend, and he pretty much goes MIA whenever he goes to visit her. It can take him up to two days to return my phone calls, and I'll have to call or text two or three times to get him to respond. (I'm contacting him about business, not social stuff.) He is usually -- well, used to be -- very available by phone. His disappearing act when he's with the girlfriend is really annoying and detrimental to our business and, frankly, pretty disrespectful. I've made jokes about it, but nothing's changed. Help.

--Annoyed

"Hello, Search and Rescue? Can you send out a team? I think my business partner is lost in his girlfriend's pants."

Tempting as it must be to blast your partner for constantly leaving you in the telephonic lurch, you'd be better off simply telling him that it feels really crappy to have your calls and texts go ignored for days; you feel disrespected. Research by social psychologist C. Daniel Batson and his colleagues suggests that we have an evolved motivation to try to alleviate others' pain, to help other humans who are struggling emotionally (or are otherwise in need). However, there's a caveat: If a person's pain or need is expressed with an attack on our behavior, we're likely to go into fight-back mode instead of "there, there, lemme see what I can do to make things better" mode.

As for why you have yet to get through to him, you write, "I've made jokes about it, but nothing's changed." Jokes are just the thing if you're putting on a show with a two-drink minimum; not so much if you're trying to communicate your needs (especially to a man). The same goes for hints. Instead, opt for healthy assertiveness -- from the start. Figure out what you need -- how soon you'd like to have a callback -- and then express that.

You may not get exactly the timetable you want, but this at least opens up a discussion: "Call you back within three hours?" he responds -- countering with "Ehh...how about five hours?" You should ultimately find this approach vastly more productive than going snarky and, say, suggesting that he and his girlfriend make love like they do in the movies -- specifically, the video in which Paris Hilton answers the phone in the middle of having sex.

I'm seeing so many women on Instagram who've had themselves made over to be super hot through cosmetic surgery and injectable fillers. They all have the same face -- with big, luscious lips and huge doll-like eyes. In every shot, they're in full makeup -- crazy eyeliner, tons of contouring. Do guys actually like this plastic Barbie look? Are guys cool with cosmetic surgery in general?

--Curious

If only these women of Instagram were honest in their photo credits: "Hair by Luigi. Makeup by Annabelle. Face by Dow Corning."

Countless men insist that they prefer "the natural look" -- no makeup (let alone surgical re-mod) -- yet they never go "Wow...gorgeous!" when you sashay toward them with a face full of unconcealed pimples. Helpfully, zoologist John R. Krebs and evolutionary biologist Richard Dawkins explain that "living organisms" can easily be tricked by crude fakes -- fakes that bear only the itsy-bitsiest resemblance to the organisms' real life stimuli.

They give the example of what I call "Popsicle birdie" -- how "a black-headed gull will show its normal aggressive response to a stuffed gull's head mounted on a stick, with no body." And then there's the male stickleback fish, which gets red on the underside when in mating mode and will attack any other red-bellied male that enters its territory. In fact, mail also seems to be a problem -- which is to say, a researcher's male sticklebacks were observed attacking the side of their aquarium when a red mail van passed by the window of the lab.

Well, guess what, fellow humans: We shouldn't be too quick to feel superior to our friends with beaks, gills, and tails. Krebs and Dawkins note that a man can get "sexually aroused" by a mere photo of a naked woman. Of course, he knows it isn't an actual woman, but the photo "has enough visual stimuli in common with the real thing to have a similar effect on his physiology."

Though it's unlikely that women getting their faces remade in Klonedashian-esque ways are versed in anthropology, the enhancements they're having done align with the female facial features that anthropologists like Douglas Jones have found are attractive to men across cultures. These are "neotenous" features -- meaning somewhat babylike ones -- like big eyes, full lips, a small jaw and chin, and clear skin. These features are basically evolution's billboard, advertising a highly desirable interior -- meaning that they are cues to health and fertility. (Of course, men just think HAWWWT.)

However, though men evolved to prioritize looks in a woman, it's obviously not all they value -- especially when they're hoping to get into a relationship. So these cosmetically and surgically redeveloped features may catch a man's eye -- but then, mentally, he may take a step back: "Oh, wait -- she's gotten all this work done." And beyond how we all tend to feel threatened and even angered by fakery, many men see a woman's extensive re-mod as a red flag, reflecting less-than-healthy psychology -- an empty interior hidden behind a fancy paint job and a new, um, deck.

Also, consider that women who get their faces and bodies remade often seem to go by the reality TV standard, which seems to stem from stripper standards -- exaggerated in-your-face sexuality. Research by Cari Goetz that I cited in a recent column finds that women with an overtly sexual look are generally not seen as long-term mating material by men. Though that research explored what women wore -- scanty attire -- it's possible that women who wear a pile of makeup, with an overtly sexual look, would trigger the same reaction in men: basically, thumbs-up for a hookup or regular sex sessions -- not so much on introducing Mom to a woman who looks as if her work uniform is sequin nipple tassels.

However, there's a counterpoint to all of this. Consider that it's now possible, through medical innovation, to survive many diseases and conditions that were usually fatal. We don't expect people with diseases to do what's "natural" -- suffer terribly and die. Maybe we're a little too harsh on women who jump ahead in the beauty hierarchy through cosmetic procedures. (After all, we don't knock men for using Rogaine, those little blue pills, or deodorant.)

Additionally, maybe stigmatizing any sort of line-jumping stops discussion of the need for restraint in beauty-upgrading. As I see it, the most successful "work" is the sort we don't notice -- women who look like themselves, only, uh, "better rested" or something. Ultimately, if a woman invites a man to meet her closest relatives, he isn't at a loss for whether she's asking him to a family reunion or to hit the aisle in Home Depot where they sell that expandable foam insulation stuff that people spray into their walls.

I'm dating this new woman. I like her a lot, but she keeps complaining that I still have pictures of my ex-girlfriend on my wall, saying that it makes her uncomfortable, especially when we're having sex. I was with my ex for a while, and we lived together. They're just pictures. What's the big deal?

--Irritated

There's a place for the photographic Museum of Relationships Past, but it isn't the area around your bed -- assuming that your sex partners don't require inflation with a bike pump.

Actual human beings have feelings. They long to be treated with dignity -- to be given the sense that others value them and care about how they make them feel. This would be reflected, for example, in replacing what, to a woman, probably looks like a wall shrine to the ex with pix of your other, less inflammatory loves, like Linda, your family's late Rottweiler.

It's possible that you have some sort of empathy gap -- something keeping you from the usually automatic "fellow feeling." This is a way researchers have described the sort of empathy that involves "emotional contagion" -- "catching" and then feeling an emotion another person's feeling, to some degree. Even if this isn't natural for you, you can bring it into your relationships through "perspective-taking" -- making an effort to imagine how another person feels in a situation. (This is different from imagining how you would feel.)

Research by C. Daniel Batson suggests that trying to feel what another person is feeling leads us to have empathy, "which has been found to evoke altruistic motivation." This means that it motivates a person to behave in kind and compassionate ways. In contrast, though imagining how we would feel if we were in the other person's shoes produces empathy, too, the researchers found that it also produces "personal distress, which has been found to evoke egoistic motivation" -- which is to say, "Me! Me! Me! All about me!"

In general, treating other people as if their feelings matter -- even when you don't share their feelings or think they're entirely legit -- makes for far happier relationships. If you aren't interested in putting in the work to show empathy, you can still have a relationship -- but with an atypical partner. Your best bet is probably a Boston fern -- specifically one advertised to have "durable plastic leaves that are resistant to fading."

Do men fall in love at first sight more than women do? My male friend says it's mostly men who'll see a woman from across a room or subway platform and fall for her. Yeah, I know that happens. Don't women do this, too? Like, a lot?

--Wondering Dude

A guy's claim of "love at first sight" plays better with the ladies than "I wanted to spend eternity with your boobs."

Research by psychologists Andrew Galperin and Martie Haselton finds that men, far more often than women, report experiencing "love at first sight." However, they conceded that "some men might be reporting some episodes of sheer sexual desire as 'love at first sight.'" (Ya think?)

This sex difference in love at first sight aligns with the different pressures ancestral men and women had to contend with to survive and pass on their genes. Because women alone get pregnant from sex, female emotions evolved to push women to take the slow route in mating -- to assess a man over time for his level of commitment and character -- lest a woman end up with a baby daddy who's all "Beep, beep! -- I'm outta here" like the Roadrunner.

Men, on the other hand, have an evolved sexual business model of volume and variety (kind of like Walmart). However, because ancestral men could bolt right after sex and still have a chance of leaving surviving descendants, it was in men's evolutionary interest to hook up with an endless parade of hot-erellas. As I often mention, female features we think of as beautiful -- like youth, clear skin, an hourglass figure, and pillowy lips -- are actually cues of health and fertility. So, not surprisingly, male mating imperatives evolved to be visually motivated -- "Do you look like the woman for me?" -- in a way female ones did not.

Ultimately, though evolved male mating psychology is pushing you -- even today -- to be eyeball-driven, understanding its origins can help you be mindful to take a step back and put in the time to explore a woman's character. This may help keep you from jumping into a relationship with some woman who turns out to be an extremely hot sociopath. As you might cry to your friends, "I'm so confused; she seemed so genuinely interested in me -- wanting to know where I bank, the name of my first pet, and the last four of my Social."

A lot of women are posting pix of themselves on Instagram in very skimpy attire. I don't feel comfortable doing that (though I'm in great shape), because I'm single and I'm afraid men would think I'm "easy." Am I right in thinking men don't take you seriously as relationship material if you post this type of pix? Or am I prudish and out of touch?

--Curious

Ideally, if you tell somebody you have a few more weeks out on disability, they don't immediately assume it's because you got really bad friction burns working the pole.

Evolutionary psychologist Cari Goetz and her colleagues note -- not surprisingly -- that men see skimpy attire on a woman as a signal that they can manipulate her into casual sex. (Women in their research also understood that men perceive skimpy attire this way.) But who actually ends up manipulating whom?

Just like in the advertising world, in the natural world, there are many, shall we say, less-than-truthful messages -- from humans, animals, and even some nasty little con artists of the plant world. Take the flower Ophrys apifera, aka the bee orchid. The bee orchid puts out fake female bee scent, and it's got markings and a slight coating of "fur" like female bees. The poor little sex-mad male bees try to hump the bee orchids and, in the process, pick up orchid pollen that they end up transferring when they try their luck with the next orchid in a lady bee suit.

Goetz and her team speculate that some women -- especially those who perceive themselves to be "low in mate value" -- use revealing attire to advertise what seems to be their hookupability and other "exploitability cues." However, these seemingly poor, defenseless sex bunnies may actually be looking to "advance their own mating and relationship goals." As for how this might work, if a man likes the casual sex and keeps coming back for more, maybe, just maybe, she can draw him into a relationship. (Hookupily ever after?)

However, this approach is a risky strategy because, as Goetz and her colleagues point out, "men found women displaying cues to sexual exploitability to be attractive as short-term mates, but, importantly, not attractive as long-term mates."

As for what you might make of all this, it's best to avoid clothes with coverage just this side of G-strings and nipple tassels, as well as overtly sexual poses (like sucking on a finger...subtle!). However, you can take advantage of evolutionary psychology research that finds that men are drawn to women with an hourglass figure (as well as...heh...women who use deceptive undergarments to fake having one). In short, your best bet is posting shots of yourself looking classysexual. This means wearing clothes that reveal your curves to a man -- but not your medical history: "I don't know her name yet, dude, but I can tell you that she had her gallbladder removed."

I love my girlfriend, but she has some weird rules about her place: no shoes inside, cabinets can't be left open, etc. We've gotten in fights when I've forgotten to do this stuff and then mentioned how ridiculous I find it. Should I have to do things I think are stupid?

--Besieged

Your girlfriend reminds you of a well-known television star. Unfortunately, it's Judge Judy.

You, like many people in relationships, have the expectation that your partner's requests should make sense. This is where you go wrong. To be human is to be kind of an idiot. We're all idiots on some level -- meaning that we all say and do things that make sense to us but that others would reasonably find utterly idiotic.

That said, our idiocy is not without benefits. Economist Robert H. Frank observes that we evolved to sometimes behave in "seemingly irrational" ways that actually serve our interests. An example would be acting out in ways that test others' commitment to us (though, typically, we don't see it that way and may not even intend to do that).

So, though your girlfriend would probably list reasons for each of her rules -- reasons you might find silly -- what isn't silly is her caring about your following them or at least caring enough to try. In short, you don't have to endorse her ideas to try to act in accordance with them and to treat her kindly when she gets upset that you've forgotten. (For example, you could say: "I'm sorry. I know it's important to you that I do this.") This would be a signal that you care deeply about her -- that you love her enough to do ridiculous things just to make her happy...maybe even to the point of handing her a shopping bag: "Look, honey! There was a sale at Prada on surgical shoe covers!"