system
Given the following post, respond as if you're commenting on Reddit:
human
Oxytocin vs. Dopamine vs. Serotinin etc?

I'm always hearing things like "hug your pet, it'll release oxytocin!" Or "high fives are just free serotonin!" Or "kissing gives you a dopamine rush!" These all just sound like pleasurable things to do but what are the real differences between these substances for a layman like me? Do different activities release different chemicals? Will Batman fool the Joker's plan to poison the water supply? So many questions!!!
gpt
Serotonin affects the hypothalamus, and regulates things like mood, appetite, sleep, sexual desire, social behavior. 
Oxytocin  makes people feel content or attached to another person, auch as a mate or a child. On the other hand, Oxytocin also makes people 
 less friendly to strangers or outsiders, so it's not exactly fairy dust. Dopamine is sometimes mistaken believed to be a "feel good" chemical, but it's not actually. Dopamine is responsible for motivation, and remembering rewards
 It's the neurotransmitter that makes you  want to do something or want to do more of it. The actual feel good chemical is endorphins.