
While shaking an infant can never be justified, reasons that may trigger the behavior can include: lack of experience in caring for crying, fussy babies and a lack of knowledge about infant development. Stress may also play a role.
Other factors that might contribute to shaking include: difficulty with impulse or anger control, a history of violent behavior, or unstable family situations, such as marital stress, divorce or financial problems. Alcohol or drug abuse and mental health problems have also been found to increase the overall risk of non-accidental injuries in children.

While these factors may explain why infants may be at greater risk, it is important to recognize that infants and children are never to blame for these adult responses.