I grew up in the post-1967 environment of urban Detroit. Many of us “whitey’s” utilized a truncated version of Alinsky:
isolate...separate...marginalize...minimize.
That resulted in the following scenario [personal anecdote follows]:
When surrounded by a group of “urban youths” intent on physical abuse, take a handful of the nearest “afro” [isolate], scream out-loud and run/drag to the nearest wall [separate & marginalize]. Bounce the offenders head off that wall [minimize].
It’s all about “respect”.
I have found that screaming at the top of your lungs, especially if you have been trained by DIs, almost always freaks the other side out.
And then you have a precious few moments to wreak havoc.
A self defense instructor had us practice screaming while doing whatever move we were involved in. Even the instructors holding the practice dummys would react to loud yells.