A link has been found between head injuries and violent crime.
AUT research shows even a single concussion can increase the risk of violent behaviour in the following decade of a persons life.
This goes beyond what happens on a rugby field.
Everyone is at risk of mild Traumatic Brain Injuries, from traffic accidents or even hitting their head on a kitchen cupboard and the potential cost to society is "huge".
Dr Alice Theadom, Professor of Clinical Sciences at AUT joined Kerre Woodham.
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