In a group,  thumb a lift refers to the phenomenon that individuals benefit from other members of the group without doing anything. The sucker effect refers to the phenomenon that when individuals find that some members of the group enjoy free riding, individuals will reduce their efforts, that is, individuals prefer to reduce their efforts and bear the consequences of reduced returns, rather than become a sucker and be thumb a lift by others.
According to the above definition, which of the followings belongs to the straw effect
Xiao Zhang liked clean and often took the initiative to clean the dormitory. Soon after, he found that other roommates no longer cleaned the dormitory. After that, even if he felt that the sanitary condition of the dormitory made him uncomfortable, he no longer cleaned it