There’s a new study that confirms what a lot of parents of red-shirted kids have known for a very long time now: children who are born in August but aren’t held back a year often perform worse in school.

Typically, teachers and educational experts suggest that children born at the end of summer delay Kindergarten for at least a year. This is done to avoid a situation in which a younger student might have a difficult time keeping up with the rest of the class due to their age -- nearly being a year younger than their peers.

According to a study by the National Bureau of Economic Research, there’s a huge link between a child’s school starting age and their cognitive development. The team of researchers behind the study say that there’s evidence of a positive relationship between older students tend to do much better than younger students who are often born at the end of summer, especially when it comes to testing scores.

The researchers put it this way: “A number of recent studies have found that children who are relatively older than their classmates at the beginning of primary school have a variety of short- and medium-run advantages such as scoring higher on standardized exams through primary and secondary school, having higher development of non-cognitive skills, and being less likely to commit a crime as a teenager or an adult.”

Children who are held back not only perform better at school but have advantages that they carry on to adulthood, too. The findings say that the early differences in maturity make have an impact on what a child does later in life, their life outcomes and their productivity. The study also suggests that there are also seasonal patterns in birth that impact a person’s mental health, and even height, life expectancy, intelligence and income later on in life, too.

The researchers have also noted that there are stark differences between children who were red-shirted and children who remained enrolled in school (despite their young age) by the third grade, both in their pattern of behavior and in their school work and grades, too.

The study goes on to say that older children have an advantage over their younger peers because they’ve had more time to develop, grow and mature. Even though an August baby might have the same IQ as a September baby, they might not be on the same level, emotionally speaking.

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