The most effective way to improve cohesion is to participate in activities collectively. The reason why some students are unsociable may be that these students feel that they have no sense of participation and existence in the activities. Another reason is that activities are really boring. . . In the former case, you, the squad leader, need to assign tasks to them, so that they can really participate in the activities and feel that the activities can't be carried out without them (wearing a top hat in legend). In the latter case, it is to find the "influence" among these lonely people and try to convince him that other lonely people will naturally come. For example, some students like to play games. You can find the leader who is usually in the game and let him participate in the activities, and then his gang will naturally follow. PS: nonsense. If the boys don't come, let the girls in the class invite them, and vice versa. Say 1000, say 10000, and fun activities are fundamental. In the past, our class had a group day every month. Although there are some unsociable elements, I still participate frequently after several times and realize the fun. Of course, there will always be 1-2 wonderful flowers in each class, so such people don't have to care too much.