We've looked at the kinds of connections we form as babies. Then we looked into how we carry that attachment into our adult life with the people around us. These are the models grounded in attachment theory, developed by John Bowlby, Mary Ainsworth, and Mary Main.
Why are we the way we are… in love?
In 1987, researchers C. Hazan and P. Shaver set out to investigate what we are like as attachment styles in romantic relationships. They analyzed questionnaires in which adults described their most important romantic relationships.
Hazan and Shaver identified three different attachment styles within romantic relationships, corresponding both to attachment styles in babies and to attachment characteristics in adults.

Secure lovers
Secure lovers describe their most important romantic relationships as happy and trusting. They manage to support their partners despite their flaws.
Their relationships also last longer. Secure lovers believe romantic feelings can rise and fall, but romantic love itself never fades.
Statistical analysis has shown that secure lovers had warmer relationships with their parents in childhood.
Avoidant lovers
Avoidant lovers are characterized by a fear of intimacy, emotional highs and lows, and jealousy. Avoidant types are often unsure of their feelings toward their romantic partners and believe romantic love can rarely last. They feel that falling in love is hard for them.
Compared with "secure lovers," "avoidant" types report colder relationships with their parents in childhood, and find their mothers in particular to be cold and rejecting.

The ambivalent attachment style
People with ambivalent attachment show both a desire for closeness, intense sexual attraction and emotional highs in romantic relationships, and emotional instability and painful jealousy.
People with this attachment style believe falling in love is easy for them, but also say that lasting and undimmed love is hard to find. Compared with secure lovers, ambivalent ones report colder relationships with their parents in childhood.
