She played with Barbie, and he threw a football. She learned to nurture others at her mother's knee. He learned to go out in the world and kick butt. But what if it turns out that the passive-seeming daughter in this enduring family stereotype wasn't the less powerful one at all?
As social scientists continue to unravel how gender plays out, it looks as if daughters are the control centres, busy stockpiling valuable emotional capital and wielding it within the family (while sons are out having all the supposed fun).
"Parents expect girls to help maintain the quality of relationships, whereas boys aren't given that much. It's an expectation we don't have for boys," says Penn State Berks professor and developmental psychologist Eric Lindsey, whose recent work uncovered what he believes is one of the key mechanisms behind these gender differences.
When observed playing with their children, mothers and fathers behaved differently; fathers were more assertive and mothers were more facilitating and co-operative. Daughters pick up signals about being more social and connected.
The patterns intensify as kids age, he says. "It's partly driven by the children themselves as they get older and learn from other settings, like with their peers, what it means to be a boy or girl. They then bring that back to their interactions with parents."
Other recent research involving girls' relationships with their teachers and their peers also mirrors this emphasis on social competency. "It's good and bad in a way," Prof. Lindsey says. "There are some studies that show that that added pressure and responsibility for girls contributes to levels of anxiety that boys don't experience."
And the brothers benefit. A recent Brigham Young University study about the effect of siblings on mental health found that having a sister protected adolescents from feeling lonely, unloved, guilty, self-conscious and fearful. It didn't matter whether the sister was older or younger, or how far apart in age she was from her siblings. Lead author Laura Padilla-Walker wrote that this finding was possibly "due to higher levels of communication and/or care-giving by sisters." Other studies have found that adoptive parents are more likely to hope for a girl than a boy.
Anita Kelly, a psychology professor at the University of Notre Dame in Indiana, recently invoked the power of daughters in a recent Psychology Today blog post about the link between parenting girls and getting divorced. Research has established that parents of a girl are 5 per cent more likely to divorce than parents of boys.
Prof. Kelly argues that, instead of the received wisdom that sons improve the quality of married life and hold families together, it's the daughters who wield influence. She cites a U.S. statistic that more than 70 per cent of divorces are initiated by wives.Based on other sociological research, she writes "… a conclusion that we might draw is that wives with daughters are less likely to stay with their husbands because they know that with a girl, they'll never be lonely or without help.
"Thus, they may be less willing to tolerate any bad behaviours from their husbands (and less willing to stay married) because they don't need their husbands as much. This idea could even explain why couples expecting girls are less likely to marry. A woman carrying a girl anticipates that she won't need a husband."
This emotional aptitude can "take on a dark side," Prof. Lindsey says. Girls can use relationships to attack and isolate other people inside and outside the family. "Boys do it too, but not as well or as often as girls."
This isn't news to parents of a child who has been bullied by a young girl. Although they don't necessarily leave behind black eyes and bruises, the so-called "relational" bullying can hurt even more deeply - and it's showing up in younger and younger girls.
The trend is addressed in a new book, Little Girls Can Be Mean: Four Steps to Bully-Proof Girls in the Early Grades by developmental psychologists Michelle Anthony of Denver and Reyna Lindert of Portland.
They point out that female bullying is maddeningly subtle.
"Friendship struggles, relational aggression and girl bullying clearly take their toll, and continue unaddressed, at least in part because the fact that these behaviours are so 'hidden' in girl culture that adults often don't even know they are happening."
Inside the family, many observers locate the "dark side" in girls' loaded relationships with their biggest role models, their mothers. Author Susan Shapiro Barash's new book You're Grounded Forever … But First Let's Go Shopping tackles what she sees as a growing phenomenon of head-strong, entitled young daughters.
To fail at fixing the mother-daughter relationship can be toxic for the whole family, she says.
"Fathers are involved with their daughters too, but the dynamic of mother and daughter is the essence of the family," she says in an interview.
But it's not all bad. While mothers are locked in a complicated clutch with their daughters, dads may have a little more freedom to flex their own nascent social muscles. As they become a stronger cultural force in the parenting sphere, dads' odes to the transformative nature of daughters are on the rise.
They may be, in turn, a clue that some of the parenting habits that instill gender are starting to change.
Troy, Mich., teacher Darrin Millar has written a new children's book called Daddy Can You? in the unabashedly weepy Love You Forever genre. It's a love letter to his two daughters, Emily, 10 and Danielle, 7, and shows him happily appeasing their requests to sit still and have his toenails painted, to bake cakes and other girly fare. The character-building goes both ways, he says.
"I came to the realization a few years ago that I needed to become a better man," he says. "I get to wear the Superman cape for a few more years."
Well-known parenting and humour blogger Steve Almond writes about his blinding love for his toddler daughter, Josie, in a moment of giggling and roughhousing in an essay reprinted from What I Would Tell Her: 28 Devoted Dads on Bringing Up, Holding On To and Letting Go of Their Daughters on babble.com.
"We all fall for our girls like this. We all worship them," he writes.