http://www.medicalnewstoday.com/medicalnews.php?newsid=30643
"Even the subtlest hints of anger or hostility in their environment sets physically abused children on prolonged 'alert', even if a conflict has nothing to do with them. The tendency to stay attentive of nearby discord is probably a natural form of self-preservation in children who routinely face aggression. But it may also explain why abused children are often so distracted at school,"
