Yahoo Lifestyle What makes middle children so special? New study finally has an answer
Does your place in the family shape your personality? A new large-scale study published in PNAS in December 2024 explores how birth order and family size may play a role—and found that middle children stand out in traits like kindness and cooperation. Researchers Michael C. Ashton and Kibeom Lee analyzed data from over 700,000 participants to explore how personality traits like kindness, humility, and openness differ across birth order and family size.
Why middle children excel in kindness and teamwork
For example, a middle child might be the one who steps in to mediate sibling arguments or shares their toys without being asked, reflecting their knack for compromise and cooperation. Researchers believe that growing up with siblings creates countless opportunities to practice compromise and teamwork—skills that naturally foster these cooperative traits.
Related: Dear middle child: You fill a special spot in my heart
How family size helps shape your personality
The study also found that sibship size, or the number of siblings you grew up with, plays a big role in shaping certain personality traits. For instance:
People from families with six or more children scored higher on kindness and humility compared to those from single-child households.
However, only children and oldest children scored slightly higher in openness to new experiences, which includes traits like intellectual curiosity and creativity.
How shared traditions and religion shape personality
Shared experiences—whether through religious traditions, family routines, or communal activities—were highlighted in the study as factors that may help children in larger families develop cooperative and compassionate personalities. The researchers noted that religious upbringing, in particular, can reinforce values like selflessness and kindness, but any environment that prioritizes mutual support and collaboration can foster these traits.
Related: It’s science: middle children are more likely to be social and successful
What about firstborns?
When looking at birth order within families of the same size, firstborns scored slightly lower on kindness and humility compared to their younger siblings. However, they showed a slight advantage in openness to new experiences, possibly reflecting their role as trailblazers within the family.
How this study stands out
Unlike previous research, this study used a detailed personality model called HEXACO, which measures six personality dimensions: kindness (Honesty-Humility), emotional resilience (Emotionality), sociability (Extraversion), cooperativeness (Agreeableness), responsibility (Conscientiousness), and openness to new experiences (Openness). This approach provided nuanced insights that earlier studies often overlooked.
The study’s credibility is further strengthened by its large and diverse sample. Participants hailed from various English-speaking countries, including the United States, Canada, and the UK, offering a broader perspective on family dynamics and personality development.
What does this mean for you?
This research reminds us that family dynamics—from the number of siblings to shared experiences—play a meaningful role in shaping who we become. As parents, creating an environment that fosters cooperation and kindness—whether in a big family or with an only child—can have lasting impacts. Remember, every family’s dynamic is unique, and the love you pour into those connections matters most.
Parenting is not about perfection but about progress. Encouraging siblings to collaborate, share, and support one another creates a foundation for lifelong kindness and resilience. Whether your child is the firstborn, middle child, youngest, or an only child, nurturing empathy and compassion can help them grow into their best selves.
Sources:
Personality differences between birth order categories. 2024. PNAS. Personality differences between birth order categories and across sibship sizes.
