AO3

• a strength is that there high external validity. This is because most observations were made by the parents and if the researchers did it there might be anxiety from the babies which might have changed how they acted
• a weakness of having the mothers as the observers is that they might have been biased in terms of what they have noticed and what they had reported due to social desirability and wanting to look like a better parent. This means that if the babies had behaved naturally their behaviour might not have been accurately recorded
• a weakness is that there is poor evidence for the asocial stage. This is because young babies are poor co-ordination and are fairly immobile which can make it hard for mothers to observe. This means that babies might be quite social but because of flawed methods they appear to be asocial
• a strength is that there are real life applications such as daycare as during the asocial and indiscriminate stage it is likely to be straight forward because babies are comforted by anyone
• a weakness of real life application is that with daycare it is with an unfamiliar adult which could be problematic during the specific attachment stage. This means that parents use of daycare can be planned suing their stages theory