When we see description/information of Pokemon in the game,we see characteristic saying like to run,alert to sound etc.So,does certain characteristics help in boosting certain stat or did game freak simply added that.
Characteristics are a feature in the Pokémon games, introduced in Generation IV. A Pokémon's Characteristic indicates which stat contains a Pokémon's highest IV. It is displayed on the Pokémon's profile screen where its Nature, date met, place met, and flavor preference (Diamond, Pearl, and Platinum only) are shown.
>A Pokémon's Characteristic is determined by the remainder of its highest IV divided by 5 (known as modulo operation in programming). Since it is built this way, Pokémon transferred from the games of Generation III via Pal Park have a Characteristic without their stats being changed.
Source: http://bulbapedia.bulbagarden.net/wiki/Characteristic
