吉姆凯西和汤姆乔德在他们的第一次谈话中透露了他们的角色。他们都是无处可住的旅行者。这成为了他们之间的紧密联系，因为这是他们共同的小经历之一。然而，他们的性格却截然不同。也就是说，与汤姆·乔德相比，吉姆·凯西更有良心，更有责任感。虽然凯西对他所做的错事总是漫不经心，但他仍然感到内疚。例如，当凯西表示没有地方可以引导人们去的时候，乔德说“带他们一圈又一圈。”引导他们”(斯坦贝克21)。与Joad的建议不同，Casey想要把人们带到某个地方，这表明他对自己的工作有义务。与之相反，乔德的反应则显示出他性格中的不负责任和轻率，因为他的反应显示出他是粗心大意的。 Furthermore, Joad does not feel guilty about his misdeed. For instance, Joad says to Casy that he is not ashamed of killing a person. This indicates the fading of Joad’s moral values because he is not regretful at all about his crime. On the contrary, Casy is guilty about his sins. When he tells Joad that he sleeps with the girls, “he looked over at Joad and his face looked helpless” (Steinbeck 22). This implies that he is compunctious about his immoral act because he looks as if he is abashed and does not know what to do. In spite of Casy’s shameful feeling, Joad, on the other hand, says “Maybe I should of been a preacher. I been a long time without a girl” (Steinbeck 22). This indicates that he thinks it is acceptable to have intimate physical contacts with women and dally with there affections, which in Casy’s opinion is sinful. In conclusion, Casy thinks relatively conscientiously and owns a sense of being responsible. Joad is relatively imprudent and has little moral sense.