Is it possible to get high scores in all personality categories?

No. Plum personality score are a reflection of an the individuals priorities. The highest score is the individuals highest priority. The lowest score is the lowest priorities, ie their greatest compromise.  

Heavily polarized scores are a good thing, because it means the individuals behavior is highly predictable. 
If someone that hasn't made any sacrifices at all, then they likely won't have any priorities either. 

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