Character Analysis
Having spent many years as a soldier in an army of newborn vampires, Jasper has come to believe that it takes a very long time for newborns to control their blood thirst and their predator nature. He therefore is surprised by Bella's ability to control her killer instincts as a newborn right from the beginning.
Jasper also plays a key role in New Moon and Eclipse, so check out his "Character Analyses" there.