Do we think all people are selfish?

要睇下你由邊個角度去睇, 從econ嘅角度去睇就一定係, 因為econ假定左每一個都係selfish
We assume all people are selfish, so that we can predict people's option.
現實來講, 以我的經驗, 係有d人唔selfish的, 佢地熱心幫助人, 樂於助人
所以係現實we can't think all people are selfish.