Yesterday, my roommate picked up some household supplies (toilet paper, sponges, etc.) and asked me to split the cost. I've bought plenty of household supplies in the two years we've lived together without ever asking for any money. It feels weird and cheap that he's suddenly doing this. Am I being unreasonable in feeling this way, or is he being seriously petty?

--Annoyed

Weird conflicts like this make you start seeing your roommate differently, and not in a good way -- kind of like Joan of Arc on horseback, brandishing an empty bottle of Lysol.

As for what might've gotten your roommate so testy about the division of expenses, the human mind seems to have a built-in bookkeeping department. This is the force at work when an irate 8-year-old announces -- "J'Accuse!" -- that her sister's slice of cake is a full three-hundredths of a millimeter bigger than hers. We seem to expect 50-50 splits (which we perceive as "fair") and get unhinged when another person gets a bigger share.

Our emotions are an essential part of our mind's accounting staff, driving us to take action to correct imbalances. Neuroscientist Matthew Lieberman has found that fairness seems to read as emotionally "rewarding" to us -- that is, feelgood. Unfairness, on the other hand, leads to "aversive" emotions (the feelbad kind), motivating us to even out the balance of things so we can feel better.

The sort of scorekeeping your roommate's engaging in seems to be triggered when people perceive they've been treated unfairly. Their perception may be wrong -- and that may actually be beneficial for them. Though we tend to assume we evolved to perceive things accurately, research by evolutionary psychologists Martie Haselton and David Buss suggests that we make self-protective errors in perception -- sometimes seeing things as greater than or less than they actually are. It seems we evolved to err in whichever direction would be least costly to us in terms of our ability to survive and mate.

In ancestral times, for example, letting somebody take advantage of us, like by freeloading, would likely have posed a greater threat to our survival than perceiving (perhaps incorrectly) that they weren't pulling their weight. Putting them on notice that we wouldn't just roll over for their slackerhood showed them (and others) that we'd stand up for ourselves, telling them that we'd make a poor choice of victim.

Even if your roommate is wrong in perceiving you as some rubber-gloved, Drano- and dish soap-poaching freeloader, as long as he feels the cleaning supplies split is unfair, it's likely to make for a toxic living situation. You could suggest using an app like Splitwise to tally up what you each spend on household supplies and then reimburse each other. (This might even show him that you are spending more or that things are close to equal.) What's important is that it makes the spending transparent and, ultimately, transparently 50-50. Because people cling to injustice (or perceived injustice), this, compassionately, allows him to have something a little more commemorative on his tombstone than "Shared living quarters with a leech. Moving on to the maggots."

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 just ended it. We had fun together and sex was great, but we're bad for each other. He's emotionally withholding, and I want love and openness in a relationship. Breaking up was the right thing, but I miss him horribly. Are there any hacks to make a breakup less devastating?

--Miserable

You say it yourself: "We're bad for each other." Staying together on these terms is like being lactose intolerant and going on a fondue cleanse.

Unfortunately, understanding this probably doesn't make amputating your partner any less devastating. But research by psychologist Lauren C. Howe suggests your perspective on the breakup matters: whether you see the breakup as an indictment or an opportunity.

Howe finds that emotional recovery after a breakup comes out of treating it "as a learning experience ... embracing rejections as opportunities for growth." Contrast this thinking -- seeing a breakup as opportunity for self-improvement -- with seeing a breakup as "self-defining," a sort of confirmation of some ugly "core truth" about oneself. Howe explains that this belief can cause the breakup to have a lingering impact, making people fear rejection and even "feel haunted by their past."

In other words, using your breakup as a conduit to the sort of relationship you want should dial down its negative effects. Focus on what you've learned and figure out what you need to do differently, like, say, quickly identifying and weeding out men who can't give you the openness and affection you're looking for. This, in turn, should help you land a man whose emotional expressiveness suggests his location on the Great Chain of Being is not directly above pictures of a cinder block and moss.

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.

Women are so mean. I'm the new girl at work, having started my job two weeks ago. Yesterday, I had a date after work, so I wore my date outfit to the office. It wasn't scandalous, but it was a little sexier than my usual workwear. I was in a bathroom stall, and I overheard two female co-workers talking about me: mean, nasty, catty talk. And really, my outfit was not terribly revealing. Why are women so awful to one another?

--Upset

Imagine if there'd been three women in the Garden of Eden -- one wearing a fig leaf a little on the small side and two to ostracize her for flirting with the snake.

Welcome to Putdownapalooza! This sort of catty little gossip fest is a female specialty -- an underhanded form of aggression against women who dare to commandeer male eyeballs.

For women, competition for mates is a beauty contest. (Sorry, but Miss Congeniality doesn't cut it.) While it's good to be a good-looking man, for men, appearance just doesn't matter as much as it does for women. Because women get pregnant and left with mouths to feed, women evolved to prioritize finding a "provider" -- a man who's willing and able to commit resources -- over landing some Mr. Adonis. Men know this, having co-evolved with women. They're more likely to dis each other and also trash each other to the ladies over how much money they make than, say, how tight their pants are.

In short, if you're an ugly millionaire, it's best if you're a man. However, if you're a hot barista or pizza delivery person, you'll still get plenty of dates -- if you're a woman. Because men evolved to prioritize physical appearance in mates, women will band together to punish other women for wearing skimpy, revealing clothes or just for being physically attractive. Women seem to recognize that other women do this. Research by social psychologist Jaimie Arona Krems suggests that women tend to dress defensively -- wear less revealing clothes and dampen their attractiveness -- when they'll be around other women that they aren't already friends with.

Prior research (by psychologist Joyce Benenson, among others) finds that girls and women tend to be vicious to newcomers in a way boys and men are not. For women, there generally seem to be "costs from incorporating a female newcomer," Krems explained to me. The women we already know -- "even those we can have some conflict with -- may be less competitive with us. At times, their gains can be our gains. And very often, female friends protect one another" -- sometimes from other women's aggression. "In fact, we might even dress a little more revealingly ... when we're with our female friends than when we're heading out alone ... perhaps because our friends have our backs."

As for you, knowing this, when you're going to be around women you aren't yet friends with, you might want to take it down a notch in sexy or wait till you're leaving work to slinky it up. Remember, as Michelle Obama said, "There is no limit to what we, as women, can accomplish" -- for example, hacking into the new office hottie's LinkedIn and promoting her to "Vice President of Lap Dances."

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, and I've developed a crush on my best friend, despite his not being my type at all. He's very confident, and I kind of want to be him. I have many insecurities, and a mutual friend suggested what I really find attractive is how my best friend knows everything about me and accepts me anyway. The more I think about it, the more I suspect our mutual friend is right.
--Wrong Reasons?

Ideally, the process of feeling good about yourself is not modeled on siphoning somebody's gas.

There's a key word in "self-acceptance" -- a big how-to clue -- and it's "self." Self-acceptance involves your embracing your whole self -- all of your qualities and characteristics, positive and negative. Psychologist Nathaniel Branden explained, "'Accepting' does not necessarily mean 'liking'" or that there's no need for improvement. It means recognizing you're a package deal, and you can't have the good stuff about you (like, say, your kindness) without the stuff that needs improvement (like how your housekeeping style is right out of Better Landfills and Dumpsters).

To crank up self-acceptance, recognize that it's not just a feeling but an action -- something you do: deciding to like yourself (and even love yourself) as a human work in progress. When you do the job of accepting yourself, you no longer need to slot somebody in as a romantic partner simply because they don't find you repellant. (If the neighbors file a complaint about the noise from your bedroom, it ideally isn't because you spend hours weeping inconsolably after sex.)

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 husband's parents interact with our 3-year-old in upsetting ways. They overfocus on her appearance, asking whether she's washed her hair or where her comb is. (She has naturally stringy hair.) They constantly quiz her, making her name colors, numbers, etc. They once spent an entire dinner trying to train her to use a napkin. My husband finally exclaimed, "She's not a performing seal!" After their last visit, she started showing anxiety that her hair doesn't look nice. How can I keep my daughter's spirit from being squelched by her grandparents?

--Worried

It's cute to see your kid playing doctor on her stuffed animal -- until you find out she's gotten a head start on a residency in plastic surgery: "Teddy felt bad about his big furry stomach, Mommy, so I'm giving him a tummy tuck and then we'll talk about laser hair removal."

Assuming Grandpa and Grandma aren't sadists with a thing for toddler torture, they've probably just succumbed to the widely believed myth that little Aristophanes or Clove will have an edge over all the other diapered Harvard hopefuls by being drilled in academics from the binky years on.

Their premature focus on your daughter's appearance probably comes from a similar place: "Can't start too early on thinking about how you present yourself!" Um, actually, you can. Research by experimental psychologist Rick M. Gardner found that girls as young as 6 had negative thoughts and feelings about their appearance. Because men evolved to prioritize physical attractiveness in a partner, women evolved to be sensitive about their looks and their placement on the prettiness totem pole. This can lead to crippling insecurity and body dysmorphia -- unfortunate at any age, but especially at age 4.

Rushing what researchers call "direct instruction" on toddlers -- expecting them to memorize and recite colors, numbers, and facts -- actually seems to set them back, harming them socially and emotionally, as well as...get this: academically!

Psychologist Gabrielle Principe explains in "Your Brain on Childhood" that neuroscience research suggests it's play, not academics, that's vital to young children's brain development. For example, when children use their imagination -- by improvising with props, creating their own games, developing storylines -- they stimulate the growth of brain cells in the frontal cortex. This area is involved in "self-regulation -- a critical skill for controlling emotions, resisting impulses, and exerting self-control and discipline."

Principe traces the myth driving today's joyless, test-prep-filled childhoods to 1960s research by UC Berkeley's Mark Rosenzweig comparing rats with super-stimulating stuff in their cages -- wheels, slides, tunnels, etc. -- with rats raised in the equivalent of empty closets. Rat Disneyland occupants did better on intelligence tests than those raised in Rat Closetland, and that's what the media reported. What the media did not report was that the rats that did best of all were the ones raised in nature, dealing with spiders, snakes, cats, fleas, and boxing matches with their rat buddies. Unfortunately, this "let the natural environment do its job" finding doesn't sell learning toys or suggest to parents that they can give their kid a leg up by treating him or her like a jar to cram with information.

Though your daughter is only 3, even slightly older children seem to be harmed by being hammered with early academics. Psychologist Peter Gray writes: "The research is clear. Academic training in kindergarten has no long-term benefit. ... It slightly increases academic test-scores in first grade, but by third grade the benefit is lost and, according to some of the best studies, by fourth grade those subjected to academic kindergartens are doing worse" academically "than those who were in play-based kindergartens."

Ultimately, it's particularly unhelpful to treat child development as a sort of race. Take the age that children start walking. Psychologist and pediatrician Arnold Gesell noted that some children walk as early as 9 months, while others start as late as 15 months. Ultimately, the early walker is no better a walker than the later one.

As for getting the grandparents to stand down, start positive: Tell them you know they love their granddaughter and want the best for her. Next, explain the research findings on both learning and appearance. Then explain that for you, what matters is that your daughter has a happy, meaningful, productive life, and this starts with her not being pushed to do things she isn't developmentally ready for.

Be prepared to remind them a few times when they forget or, um, "forget." (Well-meaning grandparents can have something in common with stubborn toddlers.) On a positive note, they did wait till after the kid was born to go all psycho "Harvard or bust!" instead of getting down by your big pregnant belly and yelling calculus theorems into your uterus.

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 friend recently bought a $3,000 labradoodle but refuses to pay to get it trained. The dog is really badly behaved. Whenever I bring up the need for training, my friend gets very defensive and lashes out at me. Last time I visited her, the dog got into my bag and chewed through some seriously expensive skin care products I treated myself to. She acted like it wasn't an issue and even said it was my fault for leaving my bag on the floor! We've been friends for nearly 20 years, so it's a little complicated, but how can I let her know her actions feel inconsiderate and get her to take proper responsibility for her dog?

--Beware Of Owner

Most dogs enjoy chewing on a nice raw bone to pass the time; hers likes to mix things up with the occasional $200 tube of eye cream.

Your friend's response to her delinquentdoodle destroying your stuff -- "Yawn...whatever" -- suggests she comes up short in a personality trait called "conscientiousness." Conscientiousness is one of the five core personality dimensions that shape how we typically behave (the other four being openness, extroversion, agreeableness, and emotional stability). Each of these dimensions reflects a spectrum -- a scale from low to high -- so, for example, extroversion includes everything from extreme extroversion to extreme introversion (the party animal versus the sort of animal that prefers hiding under a car till the shindig's over).

Research by psychologists Joshua Jackson and Brent Roberts finds that people with high conscientiousness are responsible, hardworking, orderly, and able to control their impulses. (Their work was focused on the behaviors of the conscientious, as opposed to thoughts and feelings.) Not surprisingly, other research -- a cross-cultural study by psychologist Martin C. Melchers -- finds that people with higher levels of conscientiousness tend to be more empathetic (making them less likely to react to their animal turning a friend's possessions into chew toys by being all, "Dogs will be dogs!").

Personality traits are, to a great extent, genetic, and tend to be pretty stable over time and across situations. However, psychologists Nathan Hudson and R. Chris Fraley find that a person may be able to change their personality traits, including their level of conscientiousness. Their research suggests that a person can become more conscientious by continually setting very specific weekly goals -- for example, tasks to follow through on that they'd normally let slide.

The problem is this friend of yours might need some wakeup call to be motivated to change. People who get away with living sloppy typically see no reason to live otherwise. Consider the difference in how driven someone would be to clean up their act in the wake of "hitting bottom" versus, say, "hitting middle."

Another demotivating factor might be your friend's WTR -- "welfare trade-off ratio" -- a term that unfortunately sounds like illegal food stamp swapping. In fact, as evolutionary psychologists David Buss and Lars Penke explain, a person's welfare tradeoff ratio refers to how much weight they place on their own interests relative to those of another person. In other words, "welfare" really means "well-being" -- as in, "How willing am I to sacrifice what's best for me so you can have what's good for you?"

Buss and Penke add that people who are narcissistic -- self-centered, exploitative, with a strong sense of entitlement, and lacking in empathy -- "habitually place a higher weight on their own welfare relative to the welfare of others." Now, maybe you don't see this sort of selfish, cavalier attitude coming out habitually in your friend, but maybe that's because friendship is fun-centered and thus doesn't have the sort of strains put on it that a business partnership or relationship does. (You don't have to decide whether to have an abortion because you went out for drinks with your friend.)

Where does this leave you? Unfortunately, without a lot of attractive options. Though it's reasonable to prefer that she change her philosophy on dog training (which appears to be "Why bother?") expecting her to do so is basically the love child of toxic hope and irrational expectations. Tempting as it must be to simply demand she train her dog, as you've already seen, telling people what to do tends to backfire, leading them to tell you where to go.

What you can do is choose: Consider whether the benefits of having her in your life are worth the cost. If you decide to keep her around, be realistic: Leave any pricey rejuveceuticals and anything else of value locked in a kennel when visiting her and Cujodoodle. It might also help to look on the positive side: It's only her dog running wild; she isn't hollering out the back door, "Kids, if you rob the liquor store, don't forget Mommy's merlot!"

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.