Even if you do everything right and your citizens should be running at 60% happiness, their happiness will be capped at 20% due to planet habitability. If you settle a planet with 20% habitability, that 20% becomes the cap for happiness. Your species' homeworld is 100%, other planets of the same type as your homeworld are 80%, the other types in the same category are 60%, other categories are 20%, gaia worlds are 100%.
How does anyone build an empire in this game. So how is it possible to make people happy and actually gain tech? Is the AI built to cripple the human player? This is nothing less than frustrating. eventually some presatient species gets space flight and in very little time it has 5 then 10 then 20 systems colonized and tech that surpasses mine all very quickly. I can never cause them to stop being in unrest. All of my colonies become havens of unrest. This was tried no less than 5 times with the same result. 4 science ships were set up and 2 construction ships and roughly 40% of the galaxy explored still fighting the now 5 angry colonized systems. Well, I can't expand once four planets are colonized or there about, my citizens become enraged and productivity drops to nothing. My tech and development was always way behind all of the AI ones so i set things to Huge 4-spiral galaxy with only one AI.