Study reveals how birth order and personality influence parental favoritism

Siblings share a unique bond built from shared memories, family rituals and the occasional argument. But ask almost anyone with a brother or sister and you’ll likely find a longstanding debate: who’s the favorite? New research from BYU sheds some light on that playful rivalry, revealing how parents might subtly show favoritism based on birth order, personality and gender.

The study, conducted by BYU School of Family Life professor Alex Jensen, found that younger siblings generally receive more favorable treatment from parents. Meanwhile, older siblings are often granted more autonomy, and parents are less controlling towards them as they grow up.

It is helpful to take the findings from this study and be aware of the patterns that could be happening in your family. When parents are aware, they can make small adjustments that benefit everyone.”

Alex Jensen, BYU School of Family Life professor

The study discovered parents tend to favor daughters slightly more than sons, although only parents tend to recognize the bias – children did not.

Personality also plays a big role. Children who are agreeable and responsible, regardless of birth order or gender, generally receive more favorable treatment as well.

“Most parents probably connect more easily with one child over another, whether that be due to personality, birth order, gender or other things like shared interests,” Jensen said. “Watch for those patterns within yourself. Pay attention to how your children react to things that could be perceived as favoritism.”

Jensen says it’s important to understand that these dynamics aren’t only about sibling rivalry – they’re about well-being. His other research shows that children who feel less favored by their parents are more likely to experience poor mental health and to engage in problematic behavior at home or school.

“Keep an eye out for things that seem unfair. Your children will let you know if they think something is unfair. Pay attention to them when they make that known,” Jensen said. “Either they are missing perspective and understanding, or you need to make some changes in your parenting. Make sure you are open to the latter.”

To conduct the study, Jensen and his colleagues examined data from more than 19,000 individuals, drawing from a wide range of published and unpublished sources. The research provides a broad view of how parental preferences manifest and how they can influence children throughout their lives.

“Sometimes parents get so concerned about treating their kids the same that they may overlook individual needs,” Jensen noted. “We’re not suggesting parents feel guilty; instead, parents can look at this research and use it as encouragement to look at places where they can improve, without going to extremes.”

Jensen says he’s hopeful that the study sheds light on family dynamics that are often felt but rarely discussed. Favoritism, whether intentional or unintentional, can shape sibling relationships and individual well-being. By recognizing these patterns, parents can foster stronger family bonds in meaningful ways

“The simple answers are perhaps the best. Be patient with yourself and with your children,” Jensen said. “Spend time together. Do things together that you like to do. Do things together that your children like to do. Work together, serve others together, worship together. Relationships take time and time together doing a variety of things will have many positive benefits.”