The hand is liable to be permanently damaged by caning. The buttocks are a much safer target. Also, why only for boys? Girls also have the intellectual capacity to learn from the experience. Being caned for misbehaviour taught me where the boundaries lay. I knew what I might be caned for so took steps to avoid <s>being caught</s> breaking the rules. I wasn’t always successful but I tried my best.
The 1940’s were a little before my time but what you describe bears no resemblance to the 1950’s model. We were certainly not better behaved, overall, than the boys. Sometimes we were but, at other times we were worse. Perhaps you attended a boys’ school so were not aware of the things that girls got up to at school.