In my regression model, I have created dummy variables for all binary variables in my data set. When I extract the feature importances from my model (XGBoost regression model) and plot them, I have a feature importance for all dummy variables as well (GENDER1, GENDER2, ADULT1, ADULT2, etc.).
What is the actual feature importance of the variable GENDER and ADULT in this example? Can I simply take the average of both importances, or is this mathematically wrong?