AO3 - Stages of Attachment: Schaffer

• A strength of Schaffer's research into stages of attachment is that it has high ecological validity. This is because observations were carried out on the families' own homes during ordinary activities by the parent, such as leaving the room. This makes it easier to generalise the findings to real life examples of attachment as the childrens' behaviour is likely to be representative of everyday interactions. Therefore increasing the external validity of the research into stages of attachment.
• However, Schaffer's research into stages of attachment is that it can be prone to social desirability bias as interviews were used to gather information. The mothers could have lied about their child's behaviour to present their parenting in the best possible light. For example, they may say that the child is distressed when they leave the room even if they are not. Therefore the results may have lacked internal validity and not measure the true stages of attachment.
• Schaffer's research into stages of attachment can also be criticised for culture bias as the sample used were all from Glasgow. This makes it difficult to generalise the findings of stages of attachment to other cultures. For example, psychologists studying non-western cultures where families work together to look after a child have found that infants can form multiple attachments from the outset without forming a specific attachment first. Therefore limiting the external validity of the research into stages of attachment as the formation of attachment may differ between cultures.
• A strength of Schaffer's research into stages of attachment is that it was carried out longitudinally. This means that the same children were followed up and observed regularly. This is a strength as the research does not have the confounding variable of individual differences between the children, for example, how the natural temperament of the child may affect the perception of their attachment stage. Therefore increasing the internal validity of research into stages of attachment.