The construct of emotional availability (EA) refers to the capacity of a dyad to share an emotional connection and to enjoy a mutually fulfilling and healthy relationship. The EA Scales were designed to assess multiple components of a relationship from the perspective of both partners. The four caregiver components include sensitivity, structuring, nonintrusiveness, and nonhostility; two scales measure the child's responsiveness to the caregiver and involvement of the caregiver. We describe the EA construct and introduce the papers in this issue, focusing on the contributions of this Special Section to a developmental psychopathology framework.