Don’t forget that psycho cut is a physical move and psybean is a sp atk move. It means that your Pokémon using it (let me guess : Abra line?) has a better stat in sp atk. Which is not weird at all because it’s a sp atk Pokémon. The damage is a big formula that includes stats in atk or sp atk. And that Pokémon has a waaaay better stat in sp atk. I hope it helps you. To simplify Sp atk Pokémon should use sp atk moves Physical Pokémon shoudl use physical atk moves. Some pokemons are mixed. But this is a long story. Many factors come in like nature, EV training and etc. Ciao.