Head trauma from abuse, including shaken baby syndrome, is a devastating and potentially lethal form of infant physical abuse first recognized in the early 1970s. What has been less recognized is the role of the early increase in crying in otherwise normal infants in the first few months of life as a trigger for the abuse. In part, this is because infant crying, especially prolonged unsoothable crying, has been interpreted clinically as something wrong with the infant, the infant's caregiver, or the interactions between them. Here, we review an alternative developmental interpretation, namely, that the early increase in crying is a typical behavioral development in normal infants and usually does not reflect anything wrong or abnormal. We also review evidence indicating that this normal crying pattern is the most common trigger for abusive head trauma (AHT). Together, these findings point to a conceptualization of AHT as the consequence of a failure in an otherwise common, iterative, and developmentally normal infant-caregiver interaction. They also imply that there is a window of opportunity for prevention of AHT, and potentially other forms of infant abuse, through a public health primary universal prevention strategy aimed at changing knowledge and behaviors of caregivers and society in general concerning normal development of infants and the significance of early increased infant crying. If effective, there may be important implications for prevention of infant abuse nationally and internationally.infant development | colic | excessive crying | child maltreatment | parenting A busive head trauma (AHT), also known more commonly as shaken baby syndrome (SBS), is a devastating and potentially lethal form of infant physical abuse (1). The outcomes are grim. In recognized cases, AHT typically results in death or extremely damaging injuries. About 18-25% of babies who are shaken and hospitalized die (2-7). As many as 80% of survivors have significant lifelong brain injuries (3,8,9). Although currently under study, there are no published estimates of lifetime costs per victim specific to AHT. However, the conservative estimated lifetime costs per victim is $210,012 for nonfatal child maltreatment or $1,272,900 for a death from child maltreatment (in 2010 dollars) for a total estimated economic burdern in the US for one year of $124 billion (10). Given its relative severity compared to other forms of maltreatment, these per victim estimates are likely to underestimate the lifetime costs for AHT victims. Of course, the "costs" go far beyond financial considerations, and include the destruction of families and the failure of society's moral obligation to protect defenseless infants.Preventing child maltreatment of any kind is challenging (11) because of the lack of specific stimuli for abuse, the density and difficulties of modifying risk factors in which families of maltreated children are often embedded, and the challenges of getting appropriate supports to the families. However, the convergence of our increasing un...