I do what I think is best for me: I’m striving for rewards and try to avoid punishment. Easy! And intuitive. This is basic reinforcement theory.
You can apply reinforcement theory to every behaviour, because everything can be rewarding, even punishment, just think of Sado-Masochists.
Reinforcement theory cannot be disproved: if I fail explaining behaviour with reinforcement, it’s either inherent noisiness of behaviour, the reward was not rewarding enough or the participant was wrong (damn depression!).
Though wait – if a theory cannot be falsified its not scientific.
I, personally, believe in the Spaghetti Monster. I cannot prove its existence, nor can anyone prove it doesn’t exist. That is why Spaghetti Monster is a believe and no science. As is reinforcement theory.