A weakness?

-possibility of social desirablity bias having an inmpace -Mothers were asksed to be observers and they are unlikely to be completely objective in their measures or might not have noticed the naunce of their infants behaviour -They interviewed mothers about thier children and some of them by not have reported accurate details to appear like 'better' mothers with secure attachment -Cause a bais in the data, reduce internal validity, even if the babies were behaving naturally at home, their behaviour might not have been accuratley remembered, interpreted or recorded by their mothers.