Natures
Natures can be viewed at a Pokémon's Summary Page. Natures are important to the game because they determine what berries Pokémon like and don't like. Natures are randomly generated when Eggs are hatched, with 1/21 chance of each nature. Since five natures are under the any category while there are only four in the others, you are most likely to get a Pokémon that likes any berry.
-Sour | -Spicy | -Dry | -Sweet | -Bitter | |
+Sour | - | Bold | Impish | Relaxed | Lax |
+Spicy | Lonely | - | Adamant | Brave | Naughty |
+Dry | Mild | Modest | - | Quiet | Rash |
+Sweet | Hasty | Timid | Jolly | - | Näive |
+Bitter | Gentle | Calm | Careful | Sassy | - |
Pokémon with the natures Hardy, Docile, Serious, Bashful, or Quirky can be fed any berry. However, these Pokémon receive less LUP than those with a favourite flavour.