Have you ever heard your therapist talk about attachment styles? Or referenced this in session to help you understand why and how you relate to relationships in your adult life? This article does a great job at talking about the basics to the theory from the founders perspective. Synopsis below:

John Bowlby coined what we now know today as the attachment theory. At the time, he postulated that babies experienced intense distress when separated from their primary caregiver due to adaptive reasons. With the help of Mary Ainsworth, who developed the “strange situation”, they observed the infant-parent attachment in a laboratory. Additionally, they pondered whether the attachment process can be seen throughout adult relationships as well. To further add to Bolwby’s findings, Hazan and Shaver (1987) examined attachment within the context of romantic relationships by developing a questionnaire. Today, there is a wide body of evidence supporting the notion that people in intimate adult relationships function in similar ways as infant-caregiver relationships. To gain a more comprehensive understanding of the attachment theory and its real-life implications, read this article!

Resource: http://labs.psychology.illinois.edu/~rcfraley/attachment.htm