Dar es Salaam, Dec. 29 -- GENDER-BASED violence is one of those phrases people think they understand until they are asked to explain it. Most answers come quickly, violence against women and children.

That answer is not wrong. Women and children remain the most affected and most visible victims of violence in Tanzania. But stopping there gives us only part of the picture and sometimes, the part we leave out is where the law and society fail most.

To understand gender-based violence, we must first understand gender. Gender is not biology. It is not the fact of being born male or female. Gender is social. It is how society assigns roles, expectations and power.

It shapes who is expected to lead, who is expected to submit, who is believed...