We examine height-for-age for 170,000 Indian and African children to understand why, despite two decades of sustained economic growth, the child malnutrition rate in India remains among the highest in the world. First, we show that Indian firstborns are actually taller than African firstborns; the Indian height disadvantage appears with the second child and increases with birth order. The patterns hold even when we only use between-sibling variation. Second, the birth order patterns vary with child gender and siblings' gender. Specially, the Indian firstborn height advantage only exists for sons. In addition, daughters in India with no older brothers show the sharpest height deficit relative to African counterparts; their parents are likely to have more children than planned in order to try for a son. These patterns suggest that the cultural norm of eldest son preference, which causes parents to differentially allocate resources across children by birth order and gender, keeps the average Indian child short.