Using the secure, avoidant and anxious/ambivalent categories of attachment classification, compared self-reports of childhood experience of parenting with attachment classification based on self-report of participants most significant adult, loving relationship.  Found that relative prevalence of attachment types was the same and so theorized that these two types of relationships were variants of a single underlying process: that adult romantic love was itself a process of attachment that shares important similarities with early attachment relationships. They further found that differences in adult attachment related to beliefs about self and others in ways which are consistent with attachment theory.

For this study, Hazan and Shaver developed a single-item, trichonomous measure for determining adult attachment classification according to self-report of behaviour and experience of romantic and close relationships. The single item measure later became known as the Adult Attachment Questionnaire.

The first study used an accidental sample (N=620, 205 male, 415 female. Mean age = 36) of adult respondants to a “love quiz” published in a local newspaper which questioned them about the most significant adult romantic relationship they had experienced.  Of these, 42% were married, 28% divorced or widowed, 9% cohabiting and 31% dating (some checked more than one category).  A second study using college students (N=108, 38 male, 70 female. Mean age = 18) was conducted using the same instruments plus an additional questionairre on loneliness.

Correlations obtained were significant though not strong but were higher in study 2 (students) suggesting that influence of attachment history has a decreasing effect on style of romantic relationship as individuals age. This was a ground-breaking study. Noted similarities in life-cycle of adult love (an attaching “in-love” phase leads on to a secure attachment) and childhood attachment (strong maternal attachment leads to secure attachment style).  

Highest state and trait loneliness scores (study 2 only) were obtained by anxious/ambivalent and the lowest by securely attached. Compared to adults, students were less inclined to believe love is ‘unreal’ or cannot last than adults.