Complex sentence: He tends to have a rather goofy laid back attitude, much like Carey but more so than his brother, but he can be rather responsible like when he was helping Jack to study for his driver's license in "Rebecca".
Split into simpler sentences: He tends to have a rather goofy laid back attitude, much like his brother Carey but more so. Still, he can be rather responsible such as when he helped Jack study for his driver's license in "Rebecca".