Why do siblings who grow up in a shared environment with similar parenting and equal resources often differ in intelligence? Certainly, not every child is the same, however, what’s more fascinating is that the order of birth could also be responsible for the same.Psychologists and emerging research do have the answers. so, eldest, youngest or middle; which child has a higher IQ as per science?It’s intriguing that one child may naturally take the lead in academics, another may question everything with curiosity, while a third may navigate people and situations with surprising ease. Such differences are not random. To identify the cause, scientists have looked beyond upbringing and other factors.We’ve often heard first borns being hailed as the smartest ones. And well, there may be some truth to the saying, and the credit goes to the parents. According to a research by the University of Edinburgh, first-born children have superior thinking skills to their younger siblingsAlso, economists at the University of Edinburgh, Analysis Group and the University of Sydney examined survey data collected by the US Bureau of Labor Statistics and found that first-borns scored higher than siblings in IQ tests as early as age one.Researchers have proposed several explanationsThe University of Edinburgh found that even though parents give all their children the same levels of emotional support, the first-born generally received more help with tasks that develop thinking skills.Older siblings often teach things to their younger siblings, and apparently this act enhances their own learning and skills. However, this doesn’t mean that the middle child or the younger one is not intelligent or lacking in any aspect. And this also doesn’t mean that a middle or youngest child will not outperform an older one.When it comes to parenting, it rarely stays the same with each child. However, this natural shift can create differences, even though they are unintentional. Over time this difference among siblings can influence behavior, confidence, and even how the siblings perceive themselves and each other. The key for parents here is to create a balance, and that doesn’t mean treating each child identically, it is about treating them fairly.Parents should never add labels to children. Names such as; “the smart one” or “the naughty one”; create a sense of difference in a kid's mind. It’s like a manifestation, which eventually takes place in the child’s mind. Instead of defining children by fixed traits, focus on their efforts, behaviours, and progress.Instead of making comparisons, parents should focus on each child’s unique strengths. Comparing leads to a sense of insecurity. Recognising what each child does well builds a sense of confidence. What truly shapes a child’s intelligence is education, nutrition, peer influence, along with parenting and personal motivation.