Jonah Lehrer restates the dangers:
Despite tremendous improvements in football gear and helmet technology, the rate of concussions among high school athletes has not significantly decreased in recent decades. There are many factors behind this lack of improvement, but the most important variable is the dramatic increase in both the size and speed of players. "I've seen these changes firsthand," Rollinson says. "The players I'm coaching now have muscles that you almost never saw fifteen years ago. They work out more, they drink their protein shakes, they know how to bulk up. This also means that these kids are dishing out some very big hits."