“美军第23步兵师第11旅第20团第1营C连的士兵，由于怀疑村民掩护越共逃亡，于1968年3月16日在越南广义省的美莱村（My Lai）进行的屠杀。尽管一路上美军并未发现任何敌人，但是许多士兵仍旧怀疑在越共的妻子或年迈父母家里的地下藏着民族解放阵线士兵。于是这些美国大兵们，包括由威廉?凯利中尉率领的一排，就开始朝着他们认为有敌人的地方。
在第一个平民被杀掉之后，士兵们就开始用枪、手雷、刺刀等放开手对村子里所有的人和动物实施屠杀。..。
汤普森（经过美莱村的美军侦察机机师）感到震惊，并向中尉威廉?凯利（William Calley）查询，凯利表示只是服从命令。
…. 陆军部长Howard Callaway在采访中说，凯利被减刑是因为他真的相信他是在执行上级命令。”
——引自维基百科（http://zh.wikipedia.org/wiki/%E7%BE%8E%E8%90%8A%E6%9D%91%E5%B1%A0%E6%AE%BA）
臭名昭著的“美莱村大屠杀”也引起了当时美国社会心理学家的关注，他们对此事件涉及到了心理学问题进行了大量的研究。请选择上述事件中反映出来的心理学问题
“Brigade of the army's 23rd Infantry Division 20th regiment 1th battalion Company soldiers, who suspect villagers shelter Vietcong’s fleeing. On March 16, 1968, massacre happened in My Lai of Viet Nam Quang Ngai province. Though American troops did not find any enemies in the way, many soldiers suspected national liberation front soldier hided in the underground of Viet Cong' s wife or aging parents’ home. These United States soldiers, including those led by Lieutenant William Kelly shooted towards places where they hypothesized..After the first civilian be killed, the soldiers use guns, grenades, bayonets, and so on to massacre villagers and animals..Thompson who was the engineer of American reconnaissance plane was shocked when passed the village, and inquire Lieutenant William Kelly. Kelly said he just obeyed the orders.Secretary of the army Howard Callaway said in an interview of the New York Times. Kelly was commuted because he really believed that he was on orders from superior officers.”——cited from Wikipedia11.(multiple choices)The infamous "My Lai massacre" also attracted the social psychologists’ concern of United States. Please select the psychological issues reflected in the above-mentioned incident.