Useful links for those who are interested in SEL:
As a starting point visit CASEL's webpage - it has lots of resources about SEL programmes and their effectiveness
Transforming Education is a - recently set up - American organisation focusing on developing SEL competences in students
Mindset Scholars Network includes senior american scholars and up-and-coming researchers from across the social sciences (economics, psychology, sociology, and statistics). They examine the mindsets that students need to be motivated to learn.
Edutopia has a dedicated page for SEL
ENSEC (The European Network for Social and Emotional Competence) regulary organises conferences inviting researches and practitioners interested/working in SEL in Europe
Here you can read about how SEL is important for adults as well.
And you can also see some short introductory videos on SEL here: