I am a huge advocate for healthy development of Social and Emotional Health in children. Key aspects of sociability are derived from skills that help children understand and express feelings and behaviors in ways that facilitate positive relationships. These aspects include self-regulation, active listening, cooperation, and effective communication.
This is a great article describing 3 strategies that foster sociability and social-emotional learning:
1) Teach social skills early.
2) Create shared social norms.
3) Engage students in cooperative learning.