There are a wide range of factors which may affect social development in middle childhood, including a child's environment, social status, and confidence. Each of these issues plays a major role in social development, although they may impact each child in a unique way. Self-perception and self-esteem may also play a role in social development in middle childhood because the way one views himself may impact the way he responds and interacts with others.
One issue that affects social development in middle childhood, or the ages of six through 12, is the location in which a child lives. For example, if a child who is from an affluent or weather family grows up in a predominantly lower-income area and attends school with kids who do not have as much in terms of material possessions, that child may be viewed as snobby or arrogant and could become an outcast. That same child, when raised in a town with mostly higher income families may fit in very well. The same would hold true for a child from a lower-income family, only vice versa depending on where the child grew up.
Whether or not a child is accepted in general amongst his peers will have a major impact on his social development in middle childhood. Children who are outcasts or who have few friends may not have as many opportunities to interact with other children, and they may lack social skills later on. By engaging other children in conversations and through learning how friendship, teamwork, and other social issues work, children are able to learn skills they will need throughout their lives. If a child is not able to fully engage in these situations, he will have a harder time interacting with others as an adult.
The way a child is raised will also affect his social development in middle childhood. Kids who are brought up in loving homes are more likely to treat others with the same respect and caring they are shown each day. Those who are not so lucky often act out or become secluded or "loners" at school. Children tend to mimic what they see on an everyday basis, so those who see nothing but violence, aggression, or who are made to feel inadequate will have more of a tendency to project those things on others.
A child's individual personality will also play a role in social development. Some children are naturally more able to interact successfully with others. Some are also more naturally shy or withdrawn, so social interactions may not come as easily for them.