1. When "intelligence" becomes the mantra-of-excuse after you've coached and counseled a person, you are stuck. Stop looking at what you think they are and start defining what they actually do well and where they are refusing to learn.

2. When you've defined what they do well, talk with them honestly about where they'll fit best over the long run. Yes, they may not see it that way and leave.

3. When you find that 90% of your energy is spent trying to figure out or explain 10% of your stunted performers, stop. Look at what you want from performance; compare it with what you are getting; and avoid explaining away the gap. We've all done it. We want people to succeed. And if they are likeable it's even harder. Fact: We aren't being helpful to them or the organization.

4. If it's a manager, remember this: bad managers are toxic. It's easy to believe we're dealing with a single performance issue. We're not. Toxic managers are impacting the performance of everyone around them.

5. If you think you can't live without someone, you can. What would you do if, God forbid, they dropped over tomorrow? It could happen. And life will go on.

He's certainly right to break intelligence down into its component parts rather than see "highly intelligent" on its own as a useful description when it comes to performance management.

After all, it is quite possible for a person to be positively gifted in one area and completely useless in another. It is always a mistake to assume that someone who shows extraordinary ability in one aspect of their work will necessarily be able to demonstrate a similar degree of competence in any area.

The bottom line is that being clever - even being extremely, unusually, brain-the-size-of-a-planet clever - is not the same thing as being fit for any role, particularly any leadership role. As I write this, I find the words "Gordon" and "Brown" for some reason springing to mind.