He's an asshole
This video pretty much sums it up.
- Faked having a broken arm because Rowley got attention for having a broken arm
- Has a scale of all the students in school based on popularity
- Manipulates Rowley
- Pretends to be friends with Fregly to make Rowley jealous
- Pathological Liar
I wouldn't call him a sociopath and instead an immature kid.