In DBT, Interpersonal Effectiveness refers to the skills which help us to: Attend to relationships, balance priorities versus demands, balance the “wants” and “shoulds”, build a sense of mastery and self-respect.
The goals of DBT's interpersonal effectiveness skills are to build and maintain positive relationships. DBT breaks these skills into four concrete skills. Mastering these skills can be helpful for anyone.
Not knowing what to say or how to act
Worrying about how you will say something or the outcome
You know the skills, but your emotions make it difficult for you to implement the skills
You have the skills, but you can't decide what you really want
You have the skills, but the enviornment gets in the way
Reference: From DBT® Skills Manual for Adolescents, by Jill H. Rathus and Alec L. Miller. Copyright 2015 by The Guilford Press.