I'm a 35-year-old guy who's doing online dating and who's against having kids for moral reasons. Don't get me wrong; I love kids. I just don't think we need any more people on this crowded, violent planet. I'm wondering whether I should make the "no kids" thing clear in my profile. I know this can be a major deal-breaker for many women.

--Nobody's Daddy

Saying you won't have kids for "moral reasons" sounds better than my reasons: I find them loud, sticky, and expensive. There's also the problem of how long they take to, uh, ripen, which used to be 18 years -- before kids started living at home until 30. (Many murder sentences are shorter.)

And now, bear with me as I put a buzz saw through your reasons. As for this "violent planet" business, it used to be that somebody was always cracking somebody over the head with a cudgel. But today, as psychologist Steven Pinker reports in "The Better Angels of Our Nature," the planet is less violent than ever, and violence continues to decline. As for the "crowded" argument, in 2011, National Geographic's Robert Kunzig reported that all seven billion earthlings could fit comfortably in Texas -- "if Texas were settled as densely as New York City." And it turns out that women in the U.S. aren't having enough children to replace the population dying off. According to World Bank data, American mommies are only having 1.9 children, while demographers put the replacement rate at 2.1 of the screeching, airplane seat-kicking little darlings.

The good news is that if you truly like kids, you don't have to bring them into the world to bring them into your life. There's adoption, of course (though most women who can give birth to children will want to instead of importing one "made in China"). But there are also countless kids already in existence whose divorced, widowed, or otherwise single moms have a harder time finding boyfriends -- even if they're uber-hot and so sweet they make your teeth hurt. Do profile searches for moms, and say in your profile that you don't want to create new earthlings but love kids and are open to a woman who already has some. To describe the likely spike in your popularity after hanging the "Welcome, Single Moms!" sign, well, ever watch a pack of wild dingoes descend on a downed cow?

Then again, say you like your life child-free but went all eco-pacifist so you wouldn't seem like a big meanie. Definitely put the "nobody's daddy" thing in your profile. You might also want to consider a vasectomy (with a surgeon who does loads of them, which lessens the risks). Unfortunately, getting snipped is not the deterrent to aspiring mommies you might think it would be. Women pining to spawn are prone to chirp, "Vasectomies can be reversed!" -- forgetting that it's a little harder to reverse a man's aversion to, say, tapping into a quarter-million-plus dollars of his earnings to fund orthodontia, grad school and rehab.

More bad news: For some women, not wanting kids at the moment seems to be no guarantee of not eventually wanting them. Badly. Desperately. And by the way, I've always found the "Come on, you'll want kids someday!" remark insulting, as if some random stranger at a cocktail party could know my mind better than I do. But a study in the Journal of Evolutionary Psychology by Finnish researcher Anna Rotkirch found that women -- like me -- who were sure they didn't want children sometimes found themselves suddenly experiencing "baby fever," which goes way beyond the wish to have a child. It's a painful physical longing to have a baby (often experienced in a woman's early 20s and between 28 and 35). One of Rotkirch's subjects, a woman in her 30s who knew it wasn't the right time for a child, described feeling an "agonizing" and "all-encompassing desire" to have one, to the point where she was "practically ready to rob a sperm bank."

In other words, yes: Disclose! Disclose! Disclose! State your preference in your profile. But don't think that this will be any sort of mandate for women to care about what you want. Some will -- even some of those with a uterus howling, "I WANT A BAYBEEE!" They'll be the ones who default to their ethics instead of their biology. So until there's highly reliable male birth control that doesn't require a scalpel, make it your priority to find out whether a woman is ethical before having sex with her. It's really your best -- and maybe only -- defense against the joy of bringing something into the world that spends half its time hating you and the other half begging you for money.

My girlfriend has been hurt, cheated on, and even ripped off in past relationships, and I'm paying the price. If I don't text back immediately, she is convinced I'm dumping her and flips out. If I'm busy, she thinks I'm with another girl or abandoning her. When I do something sweet, she thinks I'm trying to play her. All I want is to have a nice relationship with her. Am I fighting a losing battle, or can a little good from a caring, ethical guy allow a woman to let go of a lot of bad?

--Optimist

A woman like your girlfriend, with a history of dating shady guys, can find the most inconsequential things suspicious, down to the way you drip creamer into your coffee -- surely Morse code telling that pretty woman across the cafe that you want to have sex with her. You: "Uh...you mean the woman canoodling with her girlfriend in the 'Keep Calm and Kiss Lesbians' T-shirt?"

There are a few world-class deceivers out there, and it can be hard to see who they really are until you're looking at a small pile of cracker crumbs where the money in your bank account used to be. But, typically, a woman who's frequently chumped by bad guys is not just their victim; she's her own. Repeat suckerization often comes out of low self-worth. But it almost always comes out of refusing to do the necessary homework -- observing a potential partner's behavior over time and seeing whether it matches up with the person they claim to be. Your girlfriend appears to favor a popular shortcut -- cannonballing into a relationship and hoping things turn out okay. Until...whoops! He was just helping her best friend fix her sheets, and then the most amazing thing happened -- all of his clothes fell off.

Considering that your girlfriend probably feels cruelly abandoned whenever you stop talking long enough to sneeze, lead with the reassurance that you love her and want to be with her. Then tell her it hurts your feelings that she doesn't give you credit for who you've shown yourself to be -- a loving boyfriend who's given her no reason to believe he'd ever run some scam on her. Explain that for your relationship to make it, you need to see her working on her issues -- in a therapist's office and/or with a great reason-based self-help book, Dr. Albert Ellis' "A Guide to Rational Living" (because her flip-outs are ultimately caused by her failing to apply reason).

Gently point out that just because she has a feeling -- like jealousy or anxiety -- she doesn't have to act on it. Sure, in the moment, it's easy to go straight to crazytown. Avoiding that takes preplanning. She needs to resolve to instead pull out the evidence -- the spreadsheets of your prior behavior -- and assess the likelihood that what you're "picking up at the store" is actually just milk and not a 5'10" blonde. Give yourself a deadline to see some progress. Not necessarily miraculous change but some indication that she's trying -- and that you might someday be greeted with a kiss and a "How was your day?" instead of a gavel and a "How do you plead?"

When I talked on the phone to a woman I met on a dating site, I told her I really like hiking, and she said she did, too, so I made our first date a hike. It was a really easy hike, but she complained the whole time, wore the wrong shoes, and lagged behind. She finally admitted that she never hikes. It isn't the first time this has happened. Why do women say they like hiking when they hate it and never do it?

--Just Be Honest

Okay, so this woman's idea of an invigorating nature trek is cutting across a grassy median to get to a shoe sale. Hiking is so easy to like in the abstract, on the phone -- especially when you like hiking and the woman wants you to like her. She may even picture herself hiking -- up a fake rock in Chanel shorts at a Vogue photo shoot -- and believe that she could be into it. And then, when she feels a twinge of guilt for telling a fibby, she probably tells herself that once you fall for her, you'll realize it's a small price to pay that her feet don't take kindly to parting company with pavement. The bottom line for you? Assume that anyone you meet -- especially on the Internet -- is lying about absolutely everything until proven otherwise. (Yeah, of course she enjoys seeing birds in formation -- in valu-paks at the grocery store.)

This guy I'm dating usually texts back when I text him. But sometimes, like last night, he doesn't write back. And I'm just texting stuff like "How was your night?" -- not "OMG, I miss you." His not responding feels so disrespectful. I want to read him the riot act.

--Deeply Upset

Unfortunately, it's the rare man who has a mind-reading helmet, and even if this one does, there's a good chance it's in the back of his closet under a pile of socks containing semen specimens from the mid-'90s.

So yes, you actually do have to tell a man what you want. But choose your tone wisely. Reading a man the riot act is the right idea if you're just looking to vent and be done with him. Angrily attacking someone or even just criticizing them will set off their fight-or-flight system. Their brain dispatches a bunch of biochemical messengers to alert the internal palace guard that they're under attack. This, in turn, shuts down the systems that aren't necessary for escape or battle, such as their digestive system (yeah, whatever) and their intellect -- as in, their ability to consider your point. Oops.

To give this guy a chance to hear you and maybe even change his ways, turn to the wisdom of the world's first behavioral economist, Adam Smith. In his 1759 potboiler, "The Theory of Moral Sentiments," Smith notes that evoking someone's sympathy motivates them to want to ease the suffering of the person they're feeling sympathy for. In other words, instead of attacking the guy, simply let him know how hurt you feel when you text him and get only the cold glare of the blank screen in response -- the equivalent of his replying to some question you ask him at a party by diving over the porch railing into an embankment.

Unless he has an ashtray or another small household object where his heart is supposed to be, chances are he'll feel bad that you're feeling bad and try to reassure you. Also, as I explain in "Good Manners for Nice People Who Sometimes Say F*ck," "technology makes a nearly instant response possible; it doesn't mandate it." But by calmly explaining that you'd really appreciate a response -- at some point, even the next day -- he can lay out what works for him, and the two of you can see whether it's possible to meet in the middle. By talking instead of raging, you'll be getting off to a very good start that transcends problem-solving in the text messaging department. (If you can't tell a guy he's hurting your feelings, how can you tell him, "Slower -- and a little to the right"?)

I was crazy about this guy I started dating, but he got complacent, so I ended it. I started seeing someone else, which led my ex to proclaim that he loves me and wants me back. I recently ended things with the other guy, largely because I still have strong feelings for my ex. My ex swears he'll break up with his current girlfriend but seems in no hurry to do it. How long should I wait in the wings for him?

--Clock-watching

How long should you wait? Well, that depends on whether you're hoping to go on your first date with him in a flying car.

Relationships are "built on trust," not rust -- forming on you while you "wait in the wings" for a guy who's under no pressure to speed up the timetable on having the uncomfortable breakup conversation with his current girlfriend. Another explanation for his dawdling may be the "mere ownership effect," a behavioral economics term describing our tendency to irrationally overvalue and cling to something simply because it's already in our possession. Consumer behavior researcher Sara Loughran Dommer finds that this ownership effect is even stronger when there's an "ego threat" involved, like, oh, when your ex's thoughts of you also bring up thoughts of you dumping him (even if he did deserve it for sleeping on the job).

However, the behavioral science cookie jar has something for you, too -- "reactance," our fear of missing out on an opportunity, the principle behind "Limited-time offer!" To chip away at his current complacency, give him a two-week "grace period" to straighten things out. Allowing him some time suggests that you have strong feelings for him. Making it a limited time suggests that you have strong feelings for yourself (self-respect and, out of that, boundaries). Good things can come to those who wait -- just not so long that the movies playing on date night are Bruce Willis in "Die Hard With a Pacemaker" and Jackie Chan in "Kung Fu From a Walker."