Sexual differentiation absence of the genes that generate male genitalia do not single-handedly lead to a female brain. The male brain requires more hormones, such as testosterone, in order to properly differentiate. These hormones are released due to a gene expressed during embryonic development. Sexual differentiation Sexual differentiation is the process of development of the differences between males and females from an undifferentiated zygote. As male and female individuals develop from zygotes into fetuses, into infants, children, adolescents, and eventually into adults, sex and gender differences at many levels develop: genes, chromosomes, gonads, hormones, anatomy, and psyche. Sex differences range greatly and
Male lactation where male lactation occurs and it is not well understood what evolutionary factors control the development of this trait. The phenomenon of male lactation occurs in some species, notably the Dayak fruit bat ("Dyacopterus spadiceus"), and the lactating males may assist in the nursing of their infants. In addition, male goats are known to lactate on occasion. Human male breastfeeding is possible, but production of the hormone prolactin is necessary to induce lactation, so male lactation does not occur under normal conditions. Domperidone is a drug that can be used to increase lactation. Male lactation has also been seen during