A specific race doing something doesn't make it "their thing", just a thing they do. That may be what you mean, but some people seem to confuse the two ideas. Dreadlocks, like so many other things that get attributed to a specific race, are cultural, not racial. Culture is not race and should not be treated as such. Which is why people that whine about "cultural appropriation" are imbeciles. Likewise, people that complain about feathered headresses, etc, for Halloween costumes or football team logos are imbeciles. No group or race owns any culture.
It's no different than believing in ghosts, voodoo or alien butt probes.