- we can best understand a behaviour by seeing it as it develops.
- changes happen from an interaction of nature and nurture.
- The developmental approach provides useful attributions to everyday life - Samuel and Bryant - we now know at what stage children learn to conserve- parents and teachers can now teach the right things at correct stages to children.
- It often takes a longitudinal approach which allows us to see developments as they occur - Freud - lets us see the process through the stages of the oedipus complex - it is better to observe one child than compare children because each child is different and develops at different stages.
- It often works with children who are keen to please so can give demand characteristics - Bandura - they may have imitated the model because they thought it was the right thing to do, instead of because they were learning aggression - how do we know if it was demand characteristics, have they really learned aggression, we cannot tell if this behaviour is genuine.
- If it is long term research you can suffer from subject attrition - Freud - if at the end of the study Hans could have dropped out - if you have a big sample and some drop out then you have an unrepresentative sample, the ones left are more motivated.