For anyone interested as I am in knowing more about Bronowski, I have found an excellent, very informative blog post about his life and The Ascent of Man.  It’s clear that Jesus, where he was an undergraduate and honorary fellow, was not put off by any possible communist tendencies.

He was also pretty percipient in publishing poetry as a postgraduate by William Empson, T.H.White and Julian Bell.

https://www.jesus.cam.ac.uk/articles/ascent-man-fifty