My understanding is it's nothing to do with Colonisation, and simply just a case of doing usual BGS activities that would make the population happy. What those actions are? NFI... they don't necessarily have parity with positive/negative state effects.I'm guessing there isn't a straightforward answer as I haven't seen anything to suggest anyone who has increased it from my searches so far.
I initially thought standard living had a bearing but I'm not sure if its that in combination with other things or something entirely different.
Any thoughts all?