Parents measurably favor daughters over sons, and the child seen as most responsible over their siblings, regardless of birth order, according to a meta-analysis of 30 studies covering 19,469 participants, led by researchers Alexander Jensen of Brigham Young University and McKell Jorgensen-Wells of Western University and published in the American Psychological Association’s journal Psychological Bulletin. Nearly every parent insists, often sincerely, that they love their children equally. The data says their behavior tells a more complicated story, one most families never examine closely enough to notice.
What the Research Actually Measured
Jensen and Jorgensen-Wells didn’t rely on parents self-reporting whether they had a favorite, which tends to produce unreliable answers since most parents genuinely don’t want to admit it, even to themselves. Instead, the meta-analysis pulled together studies measuring differential treatment directly: which child received more autonomy, more resources, more warmth, and less conflict in observed or reported interactions. Pulling 30 separate studies together into one analysis, rather than relying on any single study’s sample, is what allows researchers to say the daughter-favoring and responsibility-favoring patterns are real trends rather than one-off findings from an unusual sample.
Daughters Get the Edge, From Both Parents
One of the analysis’s clearest findings is that both mothers and fathers, not just one parent, showed a consistent tilt toward favoring daughters over sons. That cuts against a common assumption that fathers might favor sons and mothers might favor daughters, evening out into rough parity across a household. The research found no such balancing effect. It’s a pattern with real downstream consequences, since children who sense they’re the less-favored one, particularly sons in this case, can carry that awareness into how they see themselves in the family and, later, into their own relationships and parenting.
Responsibility Beats Birth Order
The second major finding cuts against another widely held assumption: that oldest children are simply favored by default, given more trust because they got there first. The meta-analysis found that what actually predicted favorable treatment wasn’t birth order directly, but a child’s conscientiousness, meaning how responsible, organized, and reliable that child was perceived to be, regardless of whether they were the oldest, youngest, or somewhere in the middle. A notably responsible younger sibling could out-earn an older one’s autonomy and trust. Interestingly, the researchers found that traits like extraversion, which shape a lot of social and professional advantage outside the family, didn’t carry the same weight inside it. As Jensen put it in the American Psychological Association’s release on the findings, “Americans seem to particularly value extraverted people, but within families it” appears to matter far less than simple reliability.
That distinction matters because conscientiousness isn’t a fixed trait a child is born with in the same way temperament is. It’s shaped substantially by how a child is treated in the first place, which raises the uncomfortable possibility of a feedback loop: a child perceived as responsible gets more trust and autonomy, which reinforces the behavior that earned it, while a sibling perceived as less reliable gets less room to build that same track record.
Why This Is Worth Naming, Even If It’s Uncomfortable
The researchers are careful to note that their findings are correlational, and Jensen acknowledged plainly that “this research is correlational, so it doesn’t tell us why parents favor certain children,” only that the pattern exists and holds up across a large combined sample. That caveat matters, but it doesn’t erase the practical stakes. Perceived favoritism, whether or not a parent intends it or even recognizes it, has been linked in other research to sibling rivalry, resentment that persists into adulthood, and strained relationships between adult siblings and their parents. Naming the pattern isn’t about assigning blame to parents doing their best with limited attention and energy to divide. It’s about giving families a more honest vocabulary for a dynamic nearly everyone senses privately but few ever say out loud at the dinner table.
For parents who want to interrupt the pattern rather than simply accept it, the more useful shift isn’t trying to divide attention with a stopwatch, which tends to feel forced and doesn’t address the underlying trigger anyway. It’s noticing which child’s behavior earns trust and autonomy by default, and deliberately extending that same benefit of the doubt to a sibling who hasn’t yet had the chance to demonstrate it. Responsibility, the research suggests, is built partly through the opportunities a child is given to prove it, not solely a trait some children happen to arrive with and others don’t.
