Ernest Hemingway wrote in A Farewell to Arms that “The world breaks everyone and afterward many are strong in the broken places” (1). With the advent of industrialization, the forcible employment of children, and the 19th century child labor laws that followed, a broad recognition emerged that even childhood (or perhaps especially childhood) can be “broken” by the adversities of life in a harshly exploitative society (2). The early 20th century ethnographic work of James Agee and Walker Evans (3) depicted the privations and afflictions of poor children reared in impoverished settings, and the psychiatrist Robert Coles (4) documented the extraordinary hardships faced by young, black children during the Civil Rights Movement in the American South. The work of Yehuda et al. (5) and others (6, 7) illuminated the systematic vulnerabilities sustained by children of the Holocaust and famine survivors, and research by Evans and Schamberg (8), Shonkoff and Phillips (9), Hackman and Farah (10), Neville and colleagues (11), Lupien et al. (12), and Felitti et al. (13) has systematically documented the neurodevelopmental and health consequences of rearing in conditions of poverty and adversity. Most recently, studies by Rutter (14), Gunnar and colleagues (15), Smyke et al. (16) and Nelson et al. (17) have described the socioemotional and cognitive deficits sustained by children growing up in orphanages and other institutional settings with nonparental care. Hertzman and Boyce (18) and Hertzman and coworkers (19) have geographically mapped such deficits, linking developmental vulnerabilities at primary school entry to the unique geosocietal circumstances of individual communities. These observations, spanning a century and a half of historical time, have convincingly depicted the disordered development and fragile health incurred by children with exposures to deprivation, distress, and early life difficulties. Nonetheless, and against the odds, not all children are adversely affected by such struggles …

↵¹To whom correspondence should be addressed. E-mail: tom.boyce{at}ubc.ca.