Good question – I’m not sure I can say one branch of psychology has had the most impact. I think the beauty and strength of psychology is how it integrates some quite different perspectives together. Psychology can be quite a ‘broad church’ – for example, there is behavioural science (which integrates economics and psychology) as well as social neuroscience (which integrates bio and social approaches). I think psychology’s strength is in its flexibility to take different branches and areas and combine them. One area I find interesting is the integration of evolutionary psychology with mental health – the concepts of defeat and entrapment (associated with depression and suicide) have their basis in animal studies.
Different psychological areas have had more influence at different times. Right now, cognitive approaches are the go to for treatment of mental health disorders in society, but I’m hoping cogitive neuroscience with start to be put to good use.
Like Nicola has said, different branches/ways of thinking in psychology have their moment! It’s a bit like fashion- ways of thinking in psychology have their moment, fade away for a bit, then come back again!
Different approaches seem to be popular at different points in time!
At the moment, mindfulness and acceptance are very popular, which basically says that rather than trying to challenge and change our negative thoughts, we should accept them and try to be in the present moment rather than thinking about things that happened in the past or worrying about things that might happen in the future.
This video might help explain it better than I can! https://www.youtube.com/watch?v=qzR62JJCMBQ
Psychology is such a broad subject that, as others have said, its impact on society differs depending on the needs of society.
This is one of the reasons why I love health psychology, because it incorporates the best of all parts of psychology – biological, social, cognitive, emotional – and applies it to health (both physical and mental)