Sexual differentiation of the human brain in relation to gender identity, sexual orientation and neuropsychiatric disorders.

TY - CHAP

T1 - Sexual differentiation of the human brain in relation to gender identity, sexual orientation and neuropsychiatric disorders.

AU - Swaab, D.F.

AU - Wolff, Samantha

AU - Bao, A.M.

PY - 2022

Y1 - 2022

N2 - Gender identity (an individual’s perception of being male or female) and sexualorientation (heterosexuality, homosexuality, or bisexuality) are programmed intoour brain during early development. During the intrauterine period in the secondhalf of pregnancy, a testosterone surge masculinizes the fetal male brain. If such atestosterone surge does not occur, this will result in a feminine brain. As sexualdifferentiation of the brain takes place at a much later stage in development thansexual differentiation of the genitals, these two processes can be influencedindependently of each other and can result in gender dysphoria. Nature producesa great variability for all aspects of sexual differentiation of the brain. Mechanisms involved in sexual differentiation of the brain include hormones, genetics, epigenetics, endocrine disruptors, immune response, and self-organization. Furthermore, structural and functional differences in the hypothalamus relating to gender dysphoria and sexual orientation are described in this review. All thegenetic, postmortem, and in vivo scanning observations support the neurobiological theory about the origin of gender dysphoria, i.e., it is the sizes of brain structures, the neuron numbers, the molecular composition, functions, and connectivity of brain structures that determine our gender identity or sexual orientation.There is no evidence that one’s postnatal social environment plays a crucialrole in the development of gender identity or sexual orientation.

AB - Gender identity (an individual’s perception of being male or female) and sexualorientation (heterosexuality, homosexuality, or bisexuality) are programmed intoour brain during early development. During the intrauterine period in the secondhalf of pregnancy, a testosterone surge masculinizes the fetal male brain. If such atestosterone surge does not occur, this will result in a feminine brain. As sexualdifferentiation of the brain takes place at a much later stage in development thansexual differentiation of the genitals, these two processes can be influencedindependently of each other and can result in gender dysphoria. Nature producesa great variability for all aspects of sexual differentiation of the brain. Mechanisms involved in sexual differentiation of the brain include hormones, genetics, epigenetics, endocrine disruptors, immune response, and self-organization. Furthermore, structural and functional differences in the hypothalamus relating to gender dysphoria and sexual orientation are described in this review. All thegenetic, postmortem, and in vivo scanning observations support the neurobiological theory about the origin of gender dysphoria, i.e., it is the sizes of brain structures, the neuron numbers, the molecular composition, functions, and connectivity of brain structures that determine our gender identity or sexual orientation.There is no evidence that one’s postnatal social environment plays a crucialrole in the development of gender identity or sexual orientation.

M3 - Chapter

SP - 4347

EP - 4378

BT - Neuroscience in the 21st century

A2 - Pfaff, D.W.

A2 - Volkow, N.D.

A2 - Rubenstein, J.L.

PB - Springer Verlag GmbH

ER -