Very rarely will we come across some child who has no siblings an extrovert.
The reason seems too obvious. When a child is one among three or four siblings development of all the faculties in the child happens at a greater pace. The child goes through all the different emotions that life has in store. Happiness, sorrow, anger and jealousy are all experienced within the family before encountering them in the world around.
The single child will naturally get to know all these only much later in life. Classic example is the childhood of Siddhartha later known as Buddha. Once a child grows amidst other siblings he advances in a more balanced manner. He will start taking life as it comes. On the contrary the individual child becomes very independent, no doubt, but struggles to adapt himself with other children at school or in the playground.
It is observed that the single child tries to shy away from games and prefers sports. The child prefers not being part of any team and would like to be independent either in sports or in games. As the child has been confined to such an environment breaking the shackles would be difficult. A child who is one among siblings is found to be exactly the opposite. Generally prefers to be part of a team and contribute to the team.
We find leadership qualities in both these types of children. The former exhibits autocratic leadership while the latter exhibits democratic leadership. Both types of leadership are accepted but are applicable in different set of circumstances.