It says the group dynamic was more successful.
Did they accomplish the task?
The guy at the top that became much less active by Day 7 had come up with the answer on Day 2, wrote the report on Day 3, sending copies to the others to sign off on; and then he moved on to new tasks.
At that point, he was cut out of the loop as the others took the next several days to forge their social linkages, talk sports, and trade email jokes, until the last possible acceotable time to submit the report.
For being an seen as a non-team player, a loner, and obvious social dynamic misfit, he was fired the next day, and the company hasn't missed him at all. Tasks are still accomplished (mostly) on time, and the social dynamics are spectacular.