Schaffer and Emerson studied 60 babies from skilled working class families from Glasgow at monthly intervals for the first 18 months of life using a longitudinal approach
Schaffer and Emerson (1964) found that most babies attach to mothers by 7 months, with only 3% of babies having the father as the sole attachment figure at 7 months, and 27% having the father as a joint attachment figure
Grossmann et al (2002) found that the quality of attachment with mothers, not fathers, was related to further attachments, suggesting that father attachments are less important
Grossmann et al (2002) also found that the quality of play with fathers related to the quality of teen attachment, suggesting fathers have a different role to mothers, more to do with play and stimulation rather than emotional development
Field (1978) found that primary caregiver fathers spent more time smiling at, imitating and holding babies than secondary caregiver fathers, suggesting fathers do have the potential to be more emotion-focused primary attachment figures
Lorenz found that as long as the first thing they see is moving they will imprint on them and make sure they follow their mother, but after a certain point without seeing a thing that moves the gosling will not imprint on anything
A case study where a peacock raised in the reptile house at the zoo imprinted on a giant tortoise and displayed courtship behaviour towards them as an adult
Raised 16 monkeys with two wire mothers, one plain wire and one cloth covered wire. Found that the baby monkeys spent up to 22hr with the cloth covered mother and went to it for comfort when frightened, regardless of who gave the milk. This shows contact comfort is more important than food for attachment behaviour
Harlow followed the monkeys into adulthood and found that early maternal deprivation had a lasting negative effect, with monkeys reared with only plain wire showing the strongest effects
The type of relationship the baby experiences with the mother, will assume/expect all relationships are like that. This is a mental representation or blueprint that shapes emotional relationships later in life
Brazelton et al (1975) found that the more a baby is ignored the more distressed and less reactive a bay becomes, illustrating the role of social releasers in emotional development
Schaffer and Emerson (1964) found that even if the first attachment seems to be significantly stronger, it does not mean that it differs in quality from the other child's attachments
Controlled observation to test attachment security, involving playing in an unfamiliar room, being left alone, left with a stranger, and being reunited with a caregiver
Explore freely with little referencing of attachment figure, little or no reaction when caregiver leaves or returns, little or no stranger anxiety, do not require comfort and may avoid contact, do not seek proximity