Quantitative terms such as 'strong', 'intense' or 'weak' are not appropriate terminology in attachment theory and were very rarely used by Bowlby and Ainsworth. Instead, attachments are described and classified by their qualitative characteristics.
By the age of 18 months and probably earlier the young child has already developed discernible and specific attachment patterns to different attachment figures, based on the young child's cumulative attachment experiences with their attachment figures.
These attachment patterns are classified in two ways. One is according to whether the pattern represents an organised strategy for gaining the proximity of an attachment figure when the attachment behavioural system is activated, or the lack or collapse of such a strategy, termed disorganised. Children who have an attachment figure who is also the source of the fear which activated the attachment system are caught in an irresolvable conflict. This renders them at a loss, sometimes to the point of apparent paralysis, as to how to deactivate their attachment needs and restore a sense of comfort and security.
Attachment patterns are also classified according to whether the individual feels secure or insecure/anxious regarding the availability and responsiveness of the attachment figure.
As Bowlby points out, the term 'secure', in its original meaning, 'applies to the world as reflected in feeling and not to the world as it is' (1973, p.182). 'Safe' is perhaps a better term to describe the objective condition. Thus, a person may feel insecure although in reality they are safe and vice versa. Security and insecurity are feeling states.