It all started back in the 1950s with British psychiatrist John Bowlby. He theorized that, even taking people’s inherited temperaments into consideration, the experiences that they have with caregivers early in life influence the way they interact with caregivers later. What’s more, research over the past several decades has shown that there are distinct patterns of interpersonal interactions based on early caregiving. There are people who received consistently responsive early caregiving and who are thus comfortable depending on others—that is, individuals with a secure attachment style. There are people who had overly critical or harshly rejecting early caregiving and who, while desiring social contact, are afraid of rejection, that is, people with a fearful attachment style. There are people who experienced inconsistently responsive early caregiving and who are thus overly dependent on the approval of others, often to the point of being "clingy"—that is, individuals with a preoccupied attachment style. And finally, there are people who experienced consistently unresponsive early caregiving and who are thus uncomfortable being close to or trusting others—that is, people with a dismissing attachment style.