Researchers have found that even children as young as 7 sometimes cut themselves on purpose.
The small study is believed to be the first to examine self-injury at such a young age.
It was based on interviews with children in the Denver area and in central New Jersey, without confirmation from parents or others. But the researchers and independent experts say the results are believable, and that they raise awareness about a disturbing problem.
Overall, almost 8 percent of the third-graders -- a total of 15 kids -- said they had intentionally hurt themselves by cutting, burning or poking their skin with sharp objects, or by hitting themselves or using other methods.
About two-thirds of those children had done it more than once.
The research appears in the journal Pediatrics.
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