He made a video on this (https://youtube.com/watch?v=ZlnRlYvPvbs) where he explains he is a research scientist at MIT, but was only active from 2015 to 2020 when he switched focus to his podcast.

He published 15 first author papers during that time period: https://scholar.google.ca/citations?user=wZH_N7cAAAAJ

His research group at MIT: https://lids.mit.edu/people/research-staff