Although there are many studies investigating the long-term effects of academic red shirting, or delaying school entrance until 6 or 7 years of age, there is no clear-cut evidence. While some research poses the idea that children do show benefits or even academic improvements over time, whether or not this actually has to do with the red shirting process is not entirely clear. At its best, the evidence for long-term positive effects is inconclusive. This is not to say that there are no actual effects, simply that more studies over a greater period of time may be necessary to determine whether parents should consider this a beneficial option.
There are many variables that come into play when looking at the long-term effects of red shirting in kindergarten. According to the National Center for Education statistics, Early Childhood Longitudinal Study children who were red shirted were more likely to be white males born into families with parents who hold at least a bachelor's degree. Additionally, a red shirted child is less likely than his 5-year-old kindergarten counterparts to have gone to a preschool program in the year before starting school.
Some research suggests that the long-term effects of red shirting in kindergarten may not be entirely positive. Negative effects of red shirting may include the greater likelihood of behavioral problems over time throughout the student's academic career. Although not all students who are older at the start of school will exhibit behavioral problems, some studies do show a correlation or tie between the demonstration of these issues and the older child. Additionally, there is also some limited evidence supposing that red shirted children are more likely over time to require special education services.
There is some evidence that children who are red shirted in kindergarten may have slightly higher reading and mathematics achievement based on test scores. any observation of this effect was more of a short-term outcome than a function of long-term academic success. Outside of academic effects, it may be possible that delaying school entry may be a factor in a greater sense of self-confidence. Children who start school at an older age (i.e., over the age of 5 years) may be more confident in social interactions than peers who begin kindergarten earlier.