A huge leap of social and emotional development takes place during this phase of childhood. As children experience temper tantrums, mood swings and an expanding social world outside of their family, they have to learn more about their own emotions as well as those of other people. Parallel play evolves into learning to share toys and take turns with others. Children this age begin to separate from parents as they attend preschool and then enter Kindergarten. They are now spending time away from the home environment and starting to form their own little friendships.