Collaborative inhibition is the phrase for the day
You get more ideas out of a group than you get from an individual BUT BIG BUTT! You get less ideas per person out of a group than you would from an individual.
This is because of ‘collaborative inhibition’ – we hold back in groups for lots of cognitive reasons.
The answer? Make sure that exercises in groups and workshops always start with individual exercises (where everyone can nail a stake in the ground) and then move on to the group idea-share.