Final answer:
Males have a higher hematocrit than females due to hormonal influences on erythropoiesis, specifically the higher levels of androgens that promote RBC production.
Step-by-step explanation:
The primary reason males have a higher hematocrit than females is hormonal influences on erythropoiesis. Normal hematocrit values for males, which range from 42 to 52 with a mean value of 47, are typically higher than for females, which range from 37 to 47 with a mean value of 41. This difference is largely attributed to the effects of androgens, sex hormones that are present in higher amounts in males and that stimulate the production of red blood cells (RBCs), rather than differences in dietary iron intake, variances in blood volume, or genetic predisposition.
Furthermore, conditions such as polycythemia can affect hematocrit levels, though these are usually pathologies and not linked to the typical differences observed between males and females.