How big should a leadership team be?

Why does the size of a leadership team matter?

Size is one of the conditions behind leadership team effectiveness, alongside purpose, membership and support. Each person you add brings knowledge, perspective and reach. Each also adds costs, and research on groups has measured several of them.

The oldest idea is process loss. Ivan Steiner argued that what a group actually achieves equals what its members could achieve together, minus the losses of faulty process (Steiner, 1972). The losses he had in mind were mainly problems of coordination and of motivation.

Motivation loss has a large literature of its own. Across 78 studies, Karau and Williams (1993) found that people tend to put in less effort when working collectively than when working alone. This is called social loafing. It appeared across tasks and populations. Its strength depended on conditions such as whether individual contributions could be evaluated and how meaningful the task was.

A third loss concerns support. In a field study of 26 corporate project teams, people in larger teams were rated as performing worse individually (Mueller, 2012). The strongest explanation was what Mueller called relational loss. In larger teams, members felt less sure that colleagues would help and support them when they struggled.

Richard Hackman pointed to the links between members. As a team grows, the number of relationships to manage rises far faster than the headcount (Coutu, 2009). The arithmetic is simple: a team of 8 has 28 pairs of members, and a team of 15 has 105.

Size shows in meetings too. In two survey studies of workplace meetings, larger meetings went with lower involvement from the people attending (Leach et al., 2009). Involvement, in turn, was a key link between how a meeting was designed and how effective people judged it.

What do researchers of senior teams recommend?

Ruth Wageman, Debra Nunes, James Burruss and Richard Hackman studied more than 120 senior teams around the world (Wageman et al., 2008; Coutu, 2009). Getting the right people on the team is one of the conditions their book sets out for a great senior leadership team.

In an interview about that work, Hackman said almost every senior team they studied thought its boundaries were clear. Yet when members were asked to describe their team, fewer than 10 per cent agreed about who was on it (Coutu, 2009).

He saw the chief executive as often responsible. Some leaders fear seeming to exclude anyone; others add people for political reasons. Either way, the result can be a team that does not work. His rule of thumb was no double digits. He warned that a large senior team, such as one of all the chief executive's direct reports, may be worse than none.

Treat that number as what it is: a rule of thumb from decades of study, not a threshold tested in one study. The reasoning behind it, the cost of managing links between members, is the part to hold on to.

Hackman also described a firm where the finance chief was kept off the executive committee because he was unwilling to work towards collective solutions. The chief executive briefed him before and after every meeting, and by Hackman's account the team worked much better (Coutu, 2009). Being off the team did not mean being out of the loop.

Is there an optimal team size?

Not one that the research agrees on. The findings point in different directions, depending on the task and on what is measured.

A meta-analysis of 93 studies looked at how features of team design relate to performance (Stewart, 2006). Project and management teams performed slightly better when they had more members.

An early laboratory study used student groups of two to seven people (Hackman and Vidmar, 1970). Size made little difference to performance, but it strongly affected how members felt. Dissatisfaction rose roughly in step with group size.

So the useful question is less what number, and more what work. Every member adds knowledge and perspective, and every member adds coordination, effort and support costs. A team that must make joint decisions pays those costs in every meeting, so its core should hold only the people those decisions need.

What is a core and an extended leadership team?

One practical answer to the size problem is two circles. It is an arrangement, not a research finding, but it follows from the costs described above.

The two circles need different meetings. The core meets to decide. The extended group meets to inform, consult and align. Mixing the two tends to produce a large meeting that does neither well.

To find the core, start from the purpose of a leadership team: the tasks that only the whole team can do. Then ask who is needed for each of them.

What are the signs your leadership team is too big?

None of these is conclusive on its own. Each is a prompt to look more closely at who is in the room and why.

How do you make a leadership team smaller without shutting people out?

Hackman's view was that forming a team calls for hard decisions about membership. Not everyone who wants a seat should have one (Coutu, 2009). Hard decisions go better with clear criteria and a fair process.

Write the criteria into your leadership team charter, so that membership rests on an agreement rather than on status. People accept a boundary more readily when they can see the reason for it.

What can you do this month?

• Ask each member to write down, privately, who is on the leadership team. Compare the lists at the next meeting.
• Look at your last three agendas. Count the items that needed every member to reach a good outcome.
• List the decisions the team made together in the past quarter. For each one, note who really needed to take part.
• Try one meeting with only the decision items, and send the information items to the wider group in writing.

A tighter leadership team meeting agenda is a quick test of size. If the team's real work fits a smaller room, the room can shrink.