Currently starting planets have all meters maxed out, but happiness is at 0, which looks like an oversight to me (correct me if i'm wrong).
So i've created a PR that maxes out happiness like the other meters: https://github.com/freeorion/freeorion/pull/240
Starting Planets at max Happiness
Moderators: Oberlus, Committer
Starting Planets at max Happiness
All released under the GNU GPL 2.0 and Creative Commons Attribution-ShareAlike 3.0 licences.