Football Players and Deindividualization

    After reading about deindividuation in The Lucifer Effect, I began to wonder where we see this principle in our lives, and then realized that it applies perfectly to football players. In football, players often put a streak of black grease or face-paint underneath their eyes. I had previously thought that it was applied to help with glare, but after some research, I found that there is almost no difference between having the paint or not in terms of glare. Football players are, for the most part, relatively ordinary people in terms of kindness and aggressiveness. However, when they get on the field, they become some of the most aggressive athletes in the country. What causes this change? If we look at the Halloween example in The Lucifer effect, we can see many of the same results at work, where ordinary children become significantly more aggressive after donning a costume. If we look at this example in comparison to the football players' aggressiveness on the field, we can see that the black paint is likely a "transformative mask" for these football players, much like tribal war paint or a soldier's uniform. What do you guys think: does football players' black streaks transform them psychologically, or are they actually just glare protectors?