“Only Children never have to share their worlds with other siblings. they grow up using parents… as models. Hence, they tend to be perfectionists who are used to having their way. they set their goals exceedingly high and tend to prefer polite distance from people.”
Carlson, J., Watts, R. E., & Manniacci, M. (2006). Adlerian Personality Theory and Psychotherapy. In Adlerian therapy: Theory and practice (pp. 43-62). Washington, D.C.: American Psychological Association.