Group Punctuated Equilibrium Model

Fundamentals

The PEM asserts that groups undergo a two-phase (rather than two-staged) developmental pattern. In Phase 1, groups go through an initial period of inertia, the direction of which is set by the end of the group’s first meeting. Phase 1 lasts for half of a group’s allotted time. At the midpoint of the group’s allotted time, the group undergoes a transition that sets a revised direction for Phase 2, a second period of inertia. In addition, Gersick noted that a group’s progress is triggered more by members’ awareness of time and deadlines than by completion of an absolute amount of work in a specific developmental stage. Moreover, “halfway” emerges as the most likely moment at which groups will call attention to time or pacing. The midpoint acts as a reminder of the approaching deadline, which interrupts the group’s basic strategies at Phase I and facilitates the midpoint transition and thus the onset of Phase II.

Empirical support for the PEM was first presented by Gersick in her initial field study in which she observed eight naturally occurring groups over time and found consistent patterns of two-phase (rather than two-stage) development in these groups. Out of the eight groups observed, Gersick found that (a) every team exhibited a distinctive approach to its task as soon as it commenced and stayed with that approach through a period of inertia that lasted for half of its allotted time and (b) every group then underwent a major transition at precisely halfway between its first meeting and its official deadline, despite wide variation in the amounts of time the eight teams were allotted for their projects (ranging from 1 week to 6 months). During the transition, groups dropped old patterns, renegotiated with outside supervisors, adopted new perspectives on their work, and made dramatic progress. (c) The events that occurred during those transitions, especially a group’s interaction with its environment, shaped a new approach to the task for each group. Those approaches carried groups through a second major phase of inertial activity, in which they executed plans created at the midpoint transitions. This pattern of finding was replicated the following year in a laboratory study using experimental groups with a 1-hour life span. Gersick observed eight groups of MBA students (six groups of three members and two groups of four) designing a commercial advertisement over a 1-hour period of time and found very similar patterns of midpoint transitions. However, the transitions of the laboratory groups were less likely to be influenced by outside stakeholders.

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