AO3

• A limitation is that it may lack temporal validity. This was conducted in an era where there were few stay-at-home fathers and many women would stay at home mothers the findings may not apply to infants living in the present day where many arrangements are available in terms of child care. For example, nannies may be employed to take care of the infant from their date of birth. In this case they would need to form multiple attachments from very early on. This is a limitation as we cannot assume that all children in these arrangements will go through the same four stages at the same time as Schaffer and Emersons participants.
• A strength is that there is high external validity. The data was collected in the homes of the participants which measures the participants were more likely to behave as they normally would rather than unnatural behaviours if it was in a laboratory setting. The behaviour of the babies was unlikely to be affected by the presence of others. This means that the babies and mother would have acted how they normally would have therefore the behaviour would accurately represent real-life behaviour and attachment.
• A limitation is that the study is ungeneralizable. 60 babies and their carers from working class families in Glasgow were used. Due to all the families being involved from the same district and social class. We cannot generalise the finding as child rearing practises vary in different cultures or social classes. Furthermore, the study was conducted in the 1960s parenting styles and attachment have changed since then. Therefore the results lack temporal validity as well this suggests that attachment behaviour may be different in other cultures.
• A limitation is that there is conflicting research. Carpenter found that 2 week old babies could recognise their mother's face and voice and became distressed if the voice did not match the face. Other researchers found that breast fed babies prefer the scent of their mother's milk compared to a strangers. This is a weakness because Shaffer says that babies shouldn't feel anxiety at two weeks old but 7 months during specific stage this shows that they can develop attachments sooner than Shaffer and Emerson predict.