Six percent of people think they can beat a grizzly bear

If our ancestors could successfully hunt and kill dire wolves, which were basically larger, bigger, enormous versions of modern-day timberwolves, with just spears and flint knives, in extremely cold, frigid conditions, grizzly bears wouldn't be too much greater of a challenge.
I am pretty sure the origional context was an unarmed individual human. Groups and non-firearm weaponry could change matters. Any sort of polearm would be my choice personally, though a spear with an atlatl would be a quality choice as well. I think reach/range are my preferences.