  The link between black holes and star formation allows us to draw a
connection between black holes and the places and times extraterrestrial
intelligences (ETIs) had a greater chance of emerging. Within the context of
the gap paradigm for black holes, we show that denser cluster environments that
led to gas rich mergers and copious star formation were places less compatible
on average with the emergence of ETIs compared to isolated elliptical galaxies
by almost two orders of magnitude. The probability for ETIs peaked in these
isolated environments around 6 billion years ago and cosmic downsizing shifted
the likelihood of ETIs emerging to galaxies with weak black hole feedback, such
as in spiral galaxies, at late times.
