What further details do we learn or can we infer about Pi from chapters 1-12? What clues do we get about his personality?

The full name of Pi's character is Piscine Molitor Patel. He is shown to be a well-educated individual. He is mesmerized by sloths. He has seen a lot of sufferance in his life.  

Explanation:

He loves being in Canada but his heart still yearns for India. The name of his close friend is Francis Adirubasamy.

The author also describes Pi when he was a kid. His classmates used to tease him a lot.

Pi was an animal lover. He tried caring for animals in every way possible. He held an opinion that humans posed animals the greatest threat.

hasty generalization