I'm going to guess that the 'younger' scoring people had faster reaction times, but likely had more errors. The 'older' scoring people probably had slower times but greater accuracy. The rest of us probably fell somewhere in the middle.

Emily - didn't you you score particulary well on some other test we did where reaction time was measured? Something about sheep, maybe? I know my reaction time on that one wasn't very good...so you are definitely faster on the draw than I am!