I should emphasize right away that there is no reason to believe that any Tiv actually did practice cannibalism. The idea of eating human flesh appears to have disgusted and horrified the average Tiv as much as it would the average American. Yet for centuries, most appear to have been veritably obsessed by the suspicion that some of their neighbors—and particularly prominent men who became de facto political leaders—were, in fact, secret cannibals.
Seems more like human foibles. We think our foes must be cheating all the time and being horrible doing it.