system
Given the following post, respond as if you're commenting on Reddit:
human
ElI5: What is it about a horse's brain that makes one so willing and able to be trained...while they could so easily dominate and are so powerful, they're willing to do what we want?
gpt
Training isn't about fear or power. Do you pick your friends based on who you can beat up?

Training animals involves rewarding them, feeding them, sheltering them, and praising them selectively when they exhibit desirable behavior.

All that really determines an animal's trainability is its ability to associate behavior with reward (or punishment).