As an experiment, I tried to push one to 0/0 for happiness and 0/0 for trust. I did it, but it took hours. It was easier to make them happy and trusting.
 
I then took the unfortunate victim of my madness and boosted his happiness by adding five fluffies and boosting their happiness with constant belly rubs. He didn’t get any rubs, but they were then able to make him happy with hugs, without bringing up his trust level at all (then again, if I’m going to be a bastard to computer simulations, why should they trust me?).
 
I wasted an entire day on this, just to see how the game would react.
 
Does anyone know how to give them cookies? I saw an illustration of that here, but wasn’t able to work out the command for it.