The experiment was, he would put--the pigeon was in a cage and he'd let the pigeon get pretty hungry -hungry pigeons are not happy pigeons.

实验过程是,他把鸽子困在笼子里,还不给鸽子喂食,饥饿的鸽子怒火中烧

金融市场课程节选 : 耶鲁公开课