60 babies were assessed at regular intervals by asking the mothers questions about their behaviour when separated from their mother (separation anxiety) and towards strangers (stranger anxiety)
findings
50% of babies showed separation anxiety between 25-32 weeks
attachment was generally with the mother (specific attachment)
babies attached to the caregiver who responded most sensitively to them
by 40 weeks the babies had specific attachment and 30% had multiple
conclusion
infant attachments develop through a number of stages
evaluation
observation was carried out by the parents whilst the babies were behaving naturally- high external validity (measuring normal behaviour)
sample was limited- raised in one area of Glasgow so unrepresentative of other backgrounds
longitudinal study- same infants studied over time increasing internal validity