Basically this means a monster high in one of the three stats will be better at using an attack of that type and more likely to obey, for example a monster with the Personality type Reckless (which is high in Bravery but low in Prudence and Caring) will be more likely to use a Charge attack, whereas a monster with the Personality type Careful (a type high in Caring but low in Bravery and Prudence) will be more likely to use a Cautious attack. Personalities change quicker at lower levels than at higher levels, and monsters with a high wildness stat have harder-to-change personalities. A monster can have one of 27 personalities.