By choosing to group the data in male/female as you do and omitting the class variable, consciously or not, you can reach wrong conclusions about the interpreta

By choosing to group the data in male/female as you do and omitting the class variable, consciously or not, you can reach wrong conclusions about the interpretation of the data. See https://en.wikipedia.org/wiki/Simpson%27s_paradox https://en.wikipedia.org/wiki/Simpson%27s_paradox