Expressions of the attachment relationship outside of the strange situation.

41 preterm infants and 38 full-term infants and their mothers were observed at home at 8 and 12 months of age and in the Strange Situation at 18 months in order to compare expressions of attachment relationships in these 2 settings. There was 84% concordance in the distinctions between secure and nonsecure classifications of the mother-infant relationship made at home at 12 months and in the Strange Situation. Classifications of avoidant relationships also displayed high concordance, but only 6 of the 15 dyads classified at home as ambivalent were classified in the same way in the Strange Situation. Mothers in secure relationships as assessed in the Strange Situation were rated as more sensitive at both 8 and 12 months than mothers in either avoidant or ambivalent relationships, whereas the sensitivity of mothers in these two nonsecure relationships did not differ significantly. Infants in secure relationships in the Strange Situation were characterized by more effective secure base behavior and more affective sharing and enjoyment of physical contact, and they were less fussy or difficult during the 12-month home observations.