Encourage interaction with a more confident student

Why should I do it:

Can improve the self concept and self confidence of an insecure student
Can help students improve their connection to and rapport with other students and their association with their class and place in it
Helps students to be more outgoing, expressive, and interactive
Can increase participation and volunteering
Can help students become more social and talkative
Can improve students’ mood and attitude
Provides students with a positive role model and correct behaviors to model and duplicate
 

When should I do it:

When a student seems withdrawn, isolated, or insecure
When students appear to have poor self confidence or self concept
When a student rarely participates or volunteers
With students who are not social or have difficulty talking to others
With students that do not seem to have friends or significant connections with other students
When a student seems to have trouble fitting in or finding their place within the class
With students apologize excessively or are unsure of themselves
 

How do I do it:

You can be subtle and suggest frequently that a certain student (who you know is confident) work with, play with, help, eat lunch with, assist, etc, a student who is less confident, isolated, withdrawn, shy, etc.
You may be more formal with the intervention and speak with a confident student, asking them to interact more and help another specific student to “come  out of their shell”, participate more, be more confident and out going, etc.
You may or may not choose to explain this to the less confident student
You may speak with the less confident, withdrawn, shy, etc, student explaining you would like them to try to work more often with another specific student (who you know is confident)
When choosing partners for assignments or choosing groups for projects, make a point to place less confident students with more confident students
Praise students frequently when they exhibit confidence
You may consider giving rewards, a note home, etc. for students who exhibit certain behaviors that relay confidence, like sharing something with the class, volunteering a certain number of times, etc.