The way a crowd behaves is very different from how individuals do. I came across a phenomenon called The Bystander Effect, which means the more people are witness to an incident, the less likely anyone is to help.
A crowd does things individuals would never do.
So it makes you think, is a crowd governed by a kind of collective mind? A chanting crowd becomes a giant voice. Very strange.
Do you feel different in a crowd? All I know is I don't like being in a crowd.
Collective mind? No. I think it's that a crowd feels like a mini-society and the people take cues from "a leader".
I can think of an example:
When I got my nursing license (back in the late 80s), you took a sort of oath, a promise to announce yourself as a nurse in emergency situations, and volunteer to provide aid...in fact, you signed a document saying as much.
I pulled over and jumped out of my car at a crash site once. A lady crashed her SUV and she had 3 kids inside. Some guy sped off to find a phone to call 911 and there was a crowd of 7 or 8 people just standing around doing nothing, waiting for the ambulance. As soon as I ran past them and up to the SUV to see if anyone was injured, other people came up to it, too....and they helped.
When I realized I needed my first-aid kit, I tossed some guy my keys and he immediately ran to get it out of my truck. When I said that the kids could be safely moved, people helped them out of the car and took them a safe distance away. I explained to a lady how to cradle the driver's head and neck, to keep them stable, and gave a guy a sterile bandage and told him to keep pressure on a bleeding wound, and they both did exactly what I said, and kept doing it til EMTs got there.
While the EMTs did their thing, I asked the guy who kept pressure on the driver's wound why everyone was just standing back gawking when I got there, and he said it was because
the first person there told everyone that that particular model of SUV always caught fire and exploded in a crash. But when he saw me run right up to it, he thought "Well if that guy can do it, I can do it." And he figured I must know something about those SUVs that the first guy didn't...like maybe their explosiveness was just a rumor, or this one was a different model, or the guy was just full of shite.
I think a crowd basically picks a leader and follows them.