Younger siblings are often portrayed as reckless, scatterbrained and less put-together than their older siblings. Social science researchers have underpinned these portrayals with data, showing that younger siblings obtain, on average, slightly less education and earn slightly less in adulthood. The explanation for this has often been that firstborns get more attention and quality time from parents than their younger siblings, resulting in the latter to “act out.” Schwandt explained to Northwestern Now the implications of the findings, why people are so fascinated with birth order and the future of this research. What are some of the long-term effects that early respiratory illness exposure has on younger siblings?