Nobody has done more research on this than the US Military, specifically the special operations community.<p>The key takeaways that you find in very effective SOF teams are:<p>1. Clear and accepted authority chain (Top guy <i>earned</i> their place at the top)<p>2. Candid and constant communication&#x2F;feedback between all members<p>3. A clearly defined, proven effective and specialized role for every member with each member knowing how each others role plays together<p>4. Common sense of purpose (Objective etc...)<p>5. Common experience (BUD&#x2F;s, Q, FTC etc...)<p>If you have all of those then pretty much everything else falls into place. Note also that this has no requirement for everyone to being an &quot;A&quot; personality or whatever and has basically no bearing on what they do outside of work. Those aspects can help, but they can equally hurt depending on the egos involved.