What are we to make of fields which strongly overlap in method & subject? (I have in mind cognitive science and psychology, ML and stats.)

- Deep philosophical differences?
- Routing around a degenerate research programme?
(Cogsci was born when psych was in the grip of behaviourism, the great dead end.)
- Convergent development (incidental similarity of 2 initially distinct fields)

(Stats is certainly not degenerate, but ML is benefitting from being smaller, having less baggage IMO. Psych...)