Where’s the evidence? Self reported happiness of intelligent people in those situations does not prove anything with regard to collaboration killing creativity. What if creativity tends to come with unhappiness?
https://www.wired.com/2010/10/feeling-sad-makes-us-more-crea...
The conclusion doesn’t seem to be the people in groups are unhappy, just that the output isn’t as novel in contrast.
Maybe being happy stifles our deeper creative powers?
If creating is a reflexive behavior for adapting to circumstance, we need to be less creative on our own when we’re in a group.