Do you know some scales that allow me to specify the inclination in the anxiety-avoidance continuum? I want to know the tendency to the anxiety or to avoidance in the relationships, this, in a likert-type scale.
Not all of the measures measure the dimensions of anxiety and/or avoidance in assessing attachment quality. For adolescents one of the possible scales is IPPA (inventory of parent and peer attachment), but it measures dimensions like trust, communication and alienation. For young adults and older Parental Bonding Inventory could be a choice: it measures the loving and controlling behavior of father and mother - as experienced before age 16. In romantic attachment Experiences in Close Relationships is a reliable, widely used scale. It has revised and short versions as well. It measures avoidance of intimacy and separation anxiety. According to the theoretical model these are to uncorrelated dimensions.
I can give you answers regarding the Kim Bartholomew model of the internalize models of the self and of the other.
For peers and parents I sugest the IPPA-Inventory of parents and peers attachment (Armsden & Greenberg)
For parents the Fother/Mother Attachment Questionnaire (Matos & Costa; Faculty of Psychology and Education Sciences, University of Porto_Professor Paula Mena Matos)
For the romantic attachment I suggest the Romantic Attachment Questionnaire (Matos & Costa; Faculty of Psychology and Education Sciences, University of Porto_Professor Paula Mena Matos).
Two other recent measures you might want to check out: Fraley's ECR-RS - asessing attachment to different figures, and Gillath et al. state adult attachment measure (SAAM), see links below: