Bion drew a distinction between the basic assumption group and the work group. Within Bion’s perspective, there were always two groups present in every group setting—the overt or work group and the covert or basic assumption group.
This passage offers the clearest secondary-literature synthesis of the Basic Assumption concept, establishing the foundational structural distinction between the covert, emotionally driven Basic Assumption group and the overt, task-oriented Work group.
, Group Psychotherapy with Addicted Populations An, 1997thesis