[Homeless children] are either desperate for attention, wildly aggressive or totally withdrawn. They will bite and kick and then hug you, or they won’t talk at all. Unless kids like this can be reassured the world is safe, they are likely to be criminals by 12. By 14, they may kill.
–A pediatrician who tends homeless families
quoted in Ministries of Mercy (Keller, 1997, p.20)