#BirthOrder

The long-standing rivalry between siblings has taken a new turn as recent research shines a spotlight on a surprising “villain” within Thai and global families—the older brother. A large-scale study from the University of Warwick suggests that birth order does matter, with older brothers more likely to become the family aggressors, especially when it comes to bullying their younger siblings. This revelation not only disrupts traditional assumptions about sibling dynamics but also raises important questions about long-term well-being, family culture, and childhood development in Thailand.

A wave of new research is shedding light on the intriguing ways that your birth order—whether you’re a firstborn, middle child, youngest, or only child—can impact not just your personality, but also your risks for certain mental and physical health conditions. The longstanding folk wisdom about eldest siblings being responsible, middle children overlooked, and youngest siblings more carefree has some scientific roots—but the picture is far more complex, with direct relevance for families in Thailand and around the world.