When Chewbacca was introduced, he was shown to be quite intelligent. He could pilot the Millennium Falcon, repair complex machinery, and somehow he and Han Solo can understand each other despite a huge language barrier. Unfortunately, even Chewbacca wasnt immune to stupidity. While looking for Leia on the forest moon of Endor, he saw a dead animal hanging by a rope and grabbed it, only to be ensnared in a net, set up by the Ewoks. It didnt make sense for a Wookie with experience piloting a starship, wielding a crossbow and working with complex electronics, to fall victim for such an obvious trick. Chewbacca was always quiet yet intelligent in his scenes, always doing something useful for the sake of the Rebellion. Its just one obvious hole in terms of character development for Chewie to be so naïve, given his vast experience elsewhere in the Star Wars Universe.