r is easier to study in boys because they have only one copy whereas girls have two, one for each of their two X chromosomes. For each boy, Caspi and Moffitt collected information on the presence and frequency of their antisocial behavior and whether they were raised by parents who were caring, mildly abus

. New York: W. W. Norton & Company; 2008. HOUSE_OVERSIGHT_021274 --- PAGE BREAK --- aoe 24. 23. 26. 27. 28. 29. 30. Caspi A, Harrington H, Moffitt TE, Milne BJ, Poulton R. Socially isolated children 20 years later: risk of cardiovascular disease. Arch Pediatr Adolesc Med 2006;160:805-11. Weiss R