#52 https://samurai-gamers.com/pokemon-ultra-sun-and-moon/pokemon-refresh/
Advantages of raising your Pokemon’s Affection
There are a number of benefits that a Pokemon receives on leveling their Affection level. This ranges from experience boosts to a number of advantages in battle.
Affection
(Number of Hearts) Effects
2 Hearts ・EXP gained in battles is x 1.2
3 Hearts ・The Pokemon may still have 1 HP after receiving a blow that would
normally make it faint
4 Hearts ・May evade the enemy’s attack.
・Status effects may be healed after the turn ends.
5 Hearts ・Higher chance of landing a critical hit
por no decir que con lo de cuidar puedes quitarles efectos negativos sin tener que gastar objetos
que yo sepa el "affection" no sube solo con lo de darles mimos y de comer sino también luchando, pero lo de los mimos y comer hace que suba más rápido