Of the adjectives that are given in the first answer, I agree most with "bland."  Of course, that describes pretty much everyone in their society so I do not know if it is very helpful.

The only things that I would add to the first answer are the words "deceptive" and "oblivious."

I would say that Jonas's dad is deceptive because he does not really say what is involved in releasing a baby.  He fools Jonas and the others into believing it is something nice.

I would say he is oblivious because he is not aware of how nasty his actions and his society are.