Answer:
Curley is described as disliking bigger guys because he's small.
Step-by-step explanation:
From the quote, we are made to understand that Curley is a little guy that is unhappy with his body size and as such is envious of bigger guys and always looking for an excuse to get into altercations with them, always spoiling for a fight.
That's probably Curley's way of trying to get back at nature by being aggressive to guys that are bigger than he is.