In 1969, Bowlby defined attachment as a strong link
between two people, marking a milestone in the evolution
of the concept. Although he only described the attachment
process as being from the child to the parent, his definition
helped clarify the reciprocal parent to infant attachment
process. Research produced from this perspective
provided evidence that a secure infant to parent attachment
promotes the development of a healthy self-image
and infuences relationships in later life (Bretherton &
Waters 1985, Ainsworth 1989, Main 1991, Birtchnell 1993,
Hazan & Shaver 1994, Waters et al. 1994).