Even in areas where there is no official authority, people look up to others. The most 'popular' choice becomes the popular authority. This authority can then get away with a metric-shit-tonne more abuse than your run-of-the-mill person can. Think of the 30bad crew. One normal person on the forums says they can't quit cooked food? Attacked by the community. Banned by the 'authorities'. People accept the decision. Their 'leaders' start eating cooked food? Cooked food good. Or of some of the dumb fashion trends people follow. Everyday person wears a bright pink jacket? Pink's not popular. Pink bad. Gross. Unfashionable. Don't be seen with it. Celebrity/local popular person/fashion designer wears a bright pink jacket? Bright pink jackets sell out. Everyone seen in one at some point. Everywhere makes their own version to sell. That same person who was 'gross' before, who is still just wearing the jacket because they want to? They're hot now.
Hell, I've worked out that, if you stand nearer the edge of the curb when waiting to cross, 8/10 people waiting next-to/behind you will NOT cross until you do so. When it's safe to cross before a car and I wait on the curb, the person behind me waits. When I step out and quickly move past a car that was getting pretty damn close, that person decides it's safe to cross and walks out after me. I've almost got people run over by doing that and sprinting in the last minute. Thrilling to watch such imbecility.
Most people choose to be ruled in matters where ruling is not enforced.