Ike Robertson thinks so.
In a running league there were a lot of angry runners. Like, almost all of them. Christian Okoye, John Riggins, Ickey Woods, Larry Csonka, Natrone Means, Craig Heyward... Larry Kinnebrew... hell people forget how much Bo Jackson was angry running over the first tackler because once he did that the rest couldn't catch him.
Most old Raiders highlights would be considered evidence these days.
Man, I miss football.