The Encyclopedia of Walt Disney's Animated Characters: From Mickey ratón to Hercules by
John Grant

Walt disney Character descripción of Gaston from "Beauty and the Beast" (1991)

Where the Beast is ugy on the outsider but proves to be beautiful within, Gaston is the exact reverse: his devastatingly handsome exterior conceals a vile interior. His supervising animator, Andreas Deja, has recounted how at first he had some difficulty getting to grips with this: his natural inklination was to give Gaston something más of the looks of a villain. Then it was put to him that it was crucial for the movie that Gaston be every bit as good-looking as the Beast is repulsive, and suddenly the character took life: “When I saw the first test reels, I thought, ‘God, I know such people. Los Angeles is full of them.’” But Deja was also concerned that Gaston’s external persona shouldn’t be merely a caricature of the type we all know and loathe: “I wanted Gaston to be a dimensional character that the audience would feel they could reach out and grab.” A futher inspiration was supplied to Deja por Richard White, who was Gaston’s voice. White is an actor and singer, and as soon as Deja heard some of his early tapes he recognized that, as he put it, “it sounds like he never stops singing”. Deja decided to make this a part of Gaston’s personality - the feeling that he’s so pleased with himself and confident that everyone adores him that he can’t stop canto about himself, which indeed he does quite devastatingly in his string of self-congratulations during the tavern scene.
In fact, Gaston’s most distinguishing characteristis is not his self-adoration o his awareness of his own good looks o even his inner evil, but instead something that is central to all these character defects: his narrowness of mind. We see this not only in his quite genuine belief that Belle should find his offer of marriage irresistible: it is natural law, according to his observations, that women, always seek out the most handsome men, the natures of those men being irrelevant because, after all, women have no power of rational thought and hence lack the ability to consider such matters.
It is this narrowness which renders him incapable of understanding not only why Belle should not be bowled over with delight at the prospect of being permitted to marry him but also why she might find the Beast remotely appealing, why it should not be permissible for Gaston to mount the attack on the castle, and even why it should not be a perfectly valid act for him to stab the Beast in the back, even though the latter has just spared his life. For Gaston is unable to conceive that anything except the welfare of Gaston is remotely important - a typical sign of the sociopath. It is alarming that, as Deja and White both pointed out, there are so many Gastons around.