Answer:
The answer is: it reflects a gender difference between boys and girls during adolescence in traditional cultures.
Step-by-step explanation:
Gender differences arise from the fact that women and men are not socialized in the same way in a society, meaning, being born man or woman will define multiple experiences throughout a person's life. Gender socialization begins at a very early age, which is why by the time the person is an adolescent there will be many evident gender differences, like the one mentioned in the question.