DEFINITION:

Jaques (1992) provides a summary of the characteristics of groups most commonly described by practitioners. He suggests that a group can be said to exist as an entity when the following qualities:

Collective perception:

Members identify themselves as members of a group.

Needs:

Participation in the group will satisfy specific needs.

Shared aims:

Shared aims or ideals bind members together.

Interdependence:

An interdependence develops amongst members, whereby they are affected by and respond to event relevant to the group.

Social organisation:

A group is a social unit - with norms, roles and emotional relationships.

Interaction:

A process of communication is established which enables member to respond to each other, even when not face-to-face.

Cohesiveness:

A group has coherence with its members wishing to be members and to contribute to its successful maintenance.

Membership:

Two or more people interacting for longer than a few minutes can constitute a group.

It should be noted that these characteristics alone don't define a group and not all of them will apply to every group.

(Some theorists argue that a group has to comprise at least three people before significant group behaviour can occur).

GROUP SIZE:

As the size of a group increases, so its characteristics change. Individuals become less constrained by the norms of the group and become more aware of their feelings. Leadership and other roles become more established.

With numbers of 12 to 25 the likelihood of full face-to-face interaction decreases and sub-groups start to emerge.

When the group is over 25 in number, face-to-face interaction between everyone becomes impossible. When leadership occurs is takes a clear `external' role.