What makes a ‘favourite’ child?

Anyone with siblings has likely heard jokes about parental favouritism. True impartiality in parenting, though, is no laughing matter, with previous research showing that siblings who genuinely receive better treatment from parents tend to develop stronger mental health, healthier relationships, and better self-regulation than their less fairly-treated counterparts.

Despite research on the effects of favouritism, however, we know less about which children are likely to be favoured. Writing in Psychological Bulletin, Alexander C. Jensen and McKell A. Jorgensen-Wells explore this question — finding that gender, age, and personality can all influence whether particular children become 'the favourite'.

To understand the effects of being treated differently by parents, the team drew on data from over 19,000 individuals who had taken part in published and unpublished studies on the topic. Articles all focused on factors that might affect how parents engage with their children, such birth order, gender, temperament, and personality traits, and included both children and parents as participants.

The results suggested, initially, that younger siblings are preferred. But when the team considered other factors this favouritism disappeared; in particular, when favouritism was defined as being based on autonomy and control, older siblings came out on top.

Next, gender. Overall, parents reported slightly favouring daughters over sons, an effect that was strongest in the United States. Outside the U.S., this effect was still present — but it was weaker, suggesting cultural differences in how siblings of different genders are treated. Interestingly, children did not generally perceive this type of favouritism; this finding emerged from parental reports, suggesting some disparity in how parents and children experience favouritism.

More conscientious and agreeable children were slightly favoured, which the team suggests is because they are simply easier to parent. Other personality traits, such as openness, extraversion, and neuroticism, made no significant difference, though this may be because there was more limited data here.

The study didn't find a clear link between a child's temperament and how they're treated by parents, despite past research suggesting that more emotional children tend to get less positive parenting. This may have been due to the broadness of the term "temperament", which could include many disparate traits. Future research could focus more tightly on specific traits to better understand how a child's personality affects parenting differences.

Though initial analysis did seem to suggest that parents favour the same children consistently from childhood to adulthood, data on this was somewhat lacking in the literature. Future research may clarify this dynamic and give more insight into the way family members experience favouritism across time.

Overall, this study once again underlines that favouritism does exist, and sheds a little more light on what might lead to it. It also highlights the importance of parents being aware of their own tendencies towards favouritism. As author Alex Jensen shared in a press release for the work, "Watch for those patterns within yourself. Pay attention to how your children react to things that could be perceived as favouritism. When parents are aware, they can make small adjustments that benefit everyone."

Read the paper in full:
Jensen, A. C., & Jorgensen-Wells, M. A. (2025). Parents favor daughters: A meta-analysis of gender and other predictors of parental differential treatment. Psychological Bulletin. https://doi.org/10.1037/bul0000458

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