I have PBPs too! We have five of them, all different personalities. I don't keep them all in the same enclosure, because I have two that don't like to be together all the time. I have one that free ranges and makes a bed of hay for herself in the barn at night. The others are in stalls with goats, and we let them out to free range during the day.
We have found them to be quite smart.
Now I have a question. Apples, our free ranger pig, sometimes seems to get into "moods". I swear she sulks sometimes and gets jealous of our attention to the others, whether we are giving them treats or pats. She will then hide from us. Are they capable of emotions such as that, or are we just being silly?