My 10-year-old daughter, Birdy, is not nice, not exactly. She is deeply kind, profoundly compassionate and, probably, the most ethical person I know — but she will not smile at you unless either she is genuinely glad to see you or you’re telling her a joke that has something scatological for a punch line.

This makes her different from me. Sure, I spent the first half of the ’90s wearing a thrifted suede jacket that I had accessorized with a neon-green sticker across the back, expressing a somewhat negative attitude regarding the patriarchy (let’s just say it’s unprintable here). But even then, I smiled at everyone. Because I wanted everyone to like me. Everyone!

I am a radical, card-carrying feminist, and still I put out smiles indiscriminately, hoping to please not only friends and family but also my son’s orthodontist, the barista who rolls his eyes while I fumble apologetically through my wallet, and the ex-boyfriend who cheated on me. If I had all that energy back — all the hours and neurochemicals and facial musculature I have expended in my wanton pursuit of likedness — I could propel myself to Mars and back. Or, at the very least, write the book “Mars and Back: Gendered Constraints and Wasted Smiling.”

But it is not one thing or another, of course. My mostly pleasant way might get me more freelance work. And friendliness tends to put people at ease — loved ones, neighbors, waitresses — which is a good thing. Plus, smiling probably makes me feel happier, according to all those studies about self-fulfilling emotional prophesies. I know that our sweet-hearted son, who is 13, has always had the experience of niceness being its own reward. What can I do to help? he asks. Please, take mine, he insists, and smiles, and everyone says, “Oh, aren’t you nice!” and “What a lovely young man!” (Or sometimes, because he kind of looks like a girl, “What a lovely young lady!”) But, if I can speak frankly here, you really don’t worry about boys being too nice, do you? He still has the power and privilege of masculinity on his side, so, as far as I’m concerned, the nicer the better.

Birdy is polite in a “Can you please help me find my rain boots?” and “Thank you, I’d love another deviled egg” kind of way. But when strangers talk to her, she is like, “Whatever.” She looks away, scowling. She does not smile or encourage.

I bite my tongue so that I won’t hiss at her to be nice. I tell you this confessionally. Because do I think it is a good idea for girls to engage with zealously leering men, like the creepy guy in the hardware store who is telling her how pretty she is? I do not. “Say thank you to the nice man who wolf-whistled!” “Smile at the frat boy who’s date-raping you!” I want my daughter to be tough, to say no, to waste exactly zero of her God-given energy on the sexual, emotional and psychological demands of lame men — of lame anybodies. I don’t want her to accommodate and please. I don’t want her to wear her good nature like a gemstone, her body like an ornament.

And, currently, she is not in danger. She is decisive and no-nonsense, preferring short hair and soft pants with elastic waistbands. Dresses get in her way, and don’t even get her started on jeans, the snugly revealing allure of which completely mystifies her. She’s the kind of person who donates money to the Animal Welfare Institute and attends assiduously to all the materials they send her, including their dully depressing annual reports, which she keeps in a special folder. Gender stereotypes, among other injustices, infuriate her. “This is so stupid!” she sighs at Target, about the pink rows of dolls and the blue rows of Lego. “Why don’t they just put a penis or a vagina on every toy so you can be completely sure you’re getting the right one?”

She is tender, fierce and passionate — the kind of person who can stroke our pussycat with gentle fingers while she growls at you, her eyebrows a menacing shelf, about bedtime and her plans to avoid it. Even as a 2-year-old, she had the determined wrath and gait of a murderous zombie gnome — and my husband and I grimaced at each other, afraid, over her small and darkly glowering head. She will lift knife and fork, sighing, only if I scold her about eating with all 10 fingers like a caveman, and I have mixed feelings about that.

“She’s very moral,” a friend said recently, and it was not a compliment. She is the kid who can be a pain the neck at a play date, insisting on the rigors of turn-taking, of fair-sharing, of tidying up before the guests vamoose and leave her with an afternoon of mess to deal with. That said, though, she’s got your back. She is a patron saint of babies and animals, of the excluded or teased. “That’s not right,” she’s not afraid to say. “Stop it.”

She is a beautiful kid, but she is also sure and determined in a way that is not exactly pretty. Which is fine, because God help me if that girl ends up smiling through her entire life as if she is waitressing or pole-dancing or apologizing for some vague but enormous infraction, like the very fact of her own existence.

I picture her at the prom in stripy cotton pajamas, eating potato chips with both hands. I picture her slapping a patriarch-damning sticker on her jacket. I picture her running the country, saving the world, being exactly the kind of good bad girl that she knows herself to be. And I think: You go. I think: Fly! I think: Take me with you.