In a new study, researchers found that small teams out-innovate large teams. Smaller teams consistently find completely new ideas, while larger teams more often add information to existing ideas.
It doesn't mean that there isn't a place for large teams, it just means they are best suited to confirming or consolidating ideas, rather than generating them.
Some of the most successful companies, e.g., Google, runs on a small-team model as the company separates its employees into tightly focused teams who are focused on specific projects on a micro level. At Amazon HQ, Jeff Bezos enforces a “two-pizza” rule, where employees are discouraged from holding meetings that would require more than two pizzas to feed the entire team.
When it comes to finding the magic number for team size each company needs to see what works best for them, and it may be important to have varied team sizes within your organization, since not every group needs to be coming up with genuinely innovative concepts.
So a variety of team sizes is vital, and when in doubt, small teams are the better bet.