A recent study has found that nearly one in 20 infants worldwide experiences physical abuse by a caregiver within their first two years of life. The research, co-led by the University of British Columbia (UBC) faculty of medicine and Memorial University of Newfoundland (MUN), is the first to combine anonymous reports from caregivers about behaviors such as spanking, slapping, shaking, and hitting.
Infants rely entirely on their caregivers, which makes them particularly vulnerable to physical aggression. This can occur in various situations, including moments of stress for overtired caregivers or within families dealing with mental health challenges or existing violence at home.
Some people continue to view actions like spanking or wrist slapping as forms of discipline. However, evidence links these behaviors to lasting negative effects on children's learning, behavior, and mental health. Such actions are also associated with an increased risk of more severe violence later on. Understanding how common these behaviors are could help health systems and policymakers focus on prevention and provide support to parents before incidents escalate.
The study's authors—Dr. Fairbrother, co-lead author Cora Keeney, MUN's Dr. Jonathan Fawcett, and collaborators—reviewed 20 studies covering more than 220,000 infants and caregivers across several countries. When asked privately and anonymously, 4.8 percent of caregivers reported at least one act of physical aggression toward an infant under 24 months old. Excluding "milder" actions like spanking lowered the rate slightly to 3.9 percent but did not change the overall picture: such behavior is common yet mostly hidden.
The researchers noted that official statistics often appear lower because child-protection records typically capture only the most serious incidents that are noticed and reported by others.
"Anonymous surveys let caregivers disclose behavior that never reaches a clinic, police service or social worker," said Dr. Jon Fawcett, an assistant professor at MUN who co-led the research. "By pooling these studies, we can estimate what's really happening at a population level, not just what gets detected."
Specific types of aggression were also examined in the study. Shaking was reported at a prevalence rate between two and three percent in estimates; spanking was more common in some samples.
To address this issue, the authors suggest practical supports and policy measures. Parenting infants can be stressful due to sleep loss, frequent crying, and financial concerns—factors that may lead even calm caregivers to react impulsively during moments of frustration. The researchers recommend timely education for new parents about managing peak crying periods, accessible support lines, and home-visiting programs as potential interventions.
They also highlight the importance of clear policies against hitting children. Countries that ban physical punishment send a strong message that violence should not be part of caregiving practices.
The study calls for improved data collection from under-represented regions and further research into factors such as differences by infant age or caregiver characteristics so that prevention efforts can be better targeted.
"Infancy is the most vulnerable stage of life, and many cases of physical aggression never show up in official counts," said Dr. Fairbrother. "Knowing the true scope is the first step toward stopping it."
The findings were published in eClinicalMedicine, a journal from The Lancet.
