Predictive validity - strength
P - One strength of the Strange situation is that its outcome predicts a number of aspects of the baby's later development
E - A large body of research has shown that babies and toddlers assessed as Type B (secure) tend to have better outcomes than others, both in later childhood and in adulthood.
E - Ward et al found securely attached babies also tend to go on to have better mental health in adulthood. Those babies assessed as having insecure-resistant attachment and those not falling into types A, B or C tend to have the worst outcomes
L - This suggests that the Strange Situation measures something real and meaningful in a baby's development.