National Household Education Surveys show that about one child in seven in the U.S. either entered kindergarten late or was required to repeat kindergarten. Children usually enter kindergarten late because their parents hold them out until they are more mature.
Children usually repeat kindergarten because they are required to do so by the school system.
The surveys found that there were similarities between the kinds of children who experienced delayed entry or kindergarten repetition, but also some notable differences. Boys were reported to have been held out of kindergarten more often than girls have. Boys were also more likely to have been retained in kindergarten. The surveys found striking differences in the later school performance of children who were held out of kindergarten in contrast to those who had to repeat kindergarten. In 1995, the delayed entry students were less likely than students who entered kindergarten on time to have repeated first or second grade.