When W.I.C.K.E.D Created the Maze trials, they added 2 Peter's. one to Group A, and one to Group B.
While Group A's Peter was kind and helpful. This Peter is a know-it-all, Peter doesn't care for The Gladers at first, he dose however find Aria attractive, and It's Pretty obvious. So the Gladers made it their mission to keep him away from her.