I was in a work team once which was great fun because all of us were hugely positive and enthusiastic about what we were doing. We had all become good friends and sparked off each other beautifully when we were thinking together. I have to admit though that not all our fabulous and frequent ideas turned out to be as successful as we’d anticipated. They could sometimes be a bit hit and miss.

After a while we brought someone else into the group. We all liked him and were surprised to find that, although he was a very upbeat person normally, when it came to throwing ideas around he could be quite negative. We’d all get fired up about something and he tended to put a damper on our ideas a bit. It was slightly frustrating to find our customary enthusiasm being subdued.

After a while, however, we started to notice something else. Our hit rate was going up. More of our ideas were achieving the success we’d hoped for. You guessed it – this new guy’s negativity was forcing us to think and plan more carefully and realistically, and was helping us to anticipate potential risks and take avoiding action.

A group where everyone agrees all the time isn’t necessarily a good thing. Oh it’s great fun, and you can all slap each other on the back and congratulate yourselves. Meetings are all enjoyable and, the more similarly you think, the better time you have. Only you’re not there to have a good time. You’re there to achieve a purpose. If you all think the same way, what’s the point of having more than one of you – or maybe two just to spark each other and get the ideas flowing?

If you want to think effectively as a team, you need to avoid the kind of groupthink we were guilty of. Some groups, like ours, fall into this trap naturally because the team members are all quite alike in their thinking. Others do it because the feeling of being in agreement is so appealing that there’s an unconscious urge to override other trains of thought. Either way, the quality of your collective thinking suffers.

The most important way to avoid this is to be alert to it. Groupthink generally happens without the group noticing they’re doing it. Everyone just assumes they must be right because they all agree with each other. No one has noticed that you’re holding your meetings in an echo chamber.

Once you realise what is happening, and draw the group’s attention to it, the next stage is to address it. The best way to do this is to shake up the group – bring in other people who are reliably independent thinkers and not so likely to fall into the trap, at least not now you’re all on the lookout for it. Maybe split the group into subgroups to make it easier to set a new pattern. And make it someone’s job (or rotate it) to play devil’s advocate regularly to challenge the team’s collective ideas and conclusions.