Most kids enter kindergarten at age 5 or 6. Based on your state's entry cutoff date, a child may be allowed to enter kindergarten as early as 4. While the tangible difference between 4 and 5 is not great, children develop rapidly early in life, and the age they enter kindergarten has psychological effects on them. A 2010 study by the Philadelphia College of Osteopathic Medicine found that children who enter kindergarten early (age 4) develop at a slower rate academically for the first two years than their peers who enter kindergarten at age 5 or 6. This may lead to lower self-esteem and less confidence in academic performance down the line.
Kindergarten may be the first time that a child has to be away from home for many hours in a row. Your child may show signs of separation anxiety -- especially during the first few weeks. This behavior usually subsides as the child learns to accept the way things are and develops relationships with his classmates and teachers.
Kindergarten gives kids an opportunity to develop the basic social skills they will utilize throughout their lives. Children explore the world of friendship as they try to relate to peers. Some children will be slower to make friends than others. This is largely due to personality variations and the pressures of learning the rules of socialization. Some kids simply take longer to find their place in the microcosm of society that a school represents. At this age, children also begin realizing the differences between boys and girls. It's common for boys to stick to friendships with other boys, and girls to do the same.
Parents are pivotal in a child's development as he enters kindergarten. If possible, expose your child to the structure of a kindergarten classroom a few months before he is to begin classes. You can do this by requesting a tour of the school your child will attend and a meet-and-greet with his prospective teacher. Also, you may want to put your child into pre-kindergarten or child-care classes to increase his exposure to other children and his tolerance for authority figures other than you.