Alfred Adler was a part of Freud's inner circle along with Carl Jung until the three began to form very divergent ideas and split. Adler formed a theory of psychology based on the concepts of advantage/disadvantage and superiority/inferiority. As with all psychodynamically influenced theories, this is an example of motivational-based psychology. The concept of birth order being an important influencer of an individual's personality development also comes from Adler. 

https://www.goodtherapy.org/learn-about-therapy/types/adlerian-psychology