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Brain Development: Sex and Gender

Sexual differentiation of the brain and behavior
Abstract: During the intrauterine period the human brain develops in the male direction via direct action of a boy's testosterone, and in the female direction through the absence of this hormone in a girl. During this time, gender identity (the feeling of being a man or a woman), sexual orientation, and other behaviors are programmed. As sexual differentiation of the genitals takes places in the first 2 months of pregnancy, and sexual differentiation of the brain starts during the second half of pregnancy, these two processes may be influenced independently of each other, resulting in transsexuality. This also means that in the case of an ambiguous gender at birth, the degree of masculinization of the genitals may not reflect the same degree of masculinization of the brain. Differences in brain structures and brain functions have been found that are related to sexual orientation and gender.

Gender Development

Early androgen exposure and human gender development.
This article critically reviews the available evidence regarding influences of testosterone on human gender-related development.
Gender Development and the Human Brain [PDF]
"Gender development is multidimensional, and the combinations of factors that influence the many different dimensions of gender appear to differ."
Sexual differentiation of the human brain: relevance for gender identity, transsexualism and sexual orientation.
In the human brain, structural differences have been described that seem to be related to gender identity and sexual orientation.

Gender Dysphoria vs Body Dysmorphia (Body Dysmorphic Disorder)

GOOGLE AI Summary:

Body Dysmorphia (Body Dysmorphic Disorder):
- Individuals with body dysmorphia are preoccupied with perceived flaws in their physical appearance, (even if those flaws are not apparent to others), leading to significant distress and impairment in daily functioning.
  - Males may have body dysphoria if they feel their body looks too feminine. They can get a breast reduction, also known as gynecomastia surgery, when they have excessive breast tissue that causes physical or emotional distress.
  - Although it is more commonly known that females can get breast augmentation, females can also undergo breast reduction surgery known as reduction mammoplasty, to remove excess breast tissue when it causes physical discomfort like back or neck pain, or emotional distress related to body image or self-esteem.

Overlap:
- While the two conditions are distinct, they can overlap, and a person with gender dysphoria might also struggle with body dysmorphia related to specific body parts that they feel don't align with their gender identity.

Gender Dysphoria:
- Refers to the distress a person experiences when their internal sense of gender differs from the sex they were assigned at birth, leading to significant distress and impairment in daily functioning.

Information for Educational Professionals (BDDfoundation.org)
"Based on the available research, we know around 2% of the students in your school, college or university are likely to have this disorder [BDD]."
How Science is Helping Us Understand Gender (education.nationalgeographic.org)
EXCERPTS:
"Sexual differentiation of the genitals takes place in the first two months of pregnancy,” wrote Dick Swaab, a researcher at the Netherlands Institute for Neuroscience in Amsterdam, “and sexual differentiation of the brain starts during the second half of pregnancy.” Genitals and brains are thus subjected to different environments of “hormones, nutrients, medication, and other chemical substances,” several weeks apart in the womb, that affect sexual differentiation."
Gender Dysphoria: A Review Investigating the Relationship Between Genetic Influences and Brain Development (Adolesc Health Med Ther)
"In this test, individuals with GD [gender dysphoria] have a hypothalamic response more like that of their experienced gender, rather than their genetic sex."
Understanding transgender people, gender identity and gender expression (apa.org)
What is the difference between sex and gender?
--- Sex is assigned at birth, refers to one’s biological status as either male or female, [or best guess]
and is associated primarily with physical attributes such as chromosomes, hormone prevalence, and external and internal anatomy.
--- Gender refers to the socially constructed roles, behaviors, activities, and attributes that a given society considers appropriate for boys and men or girls and women. These influence the ways that people act, interact, and feel about themselves. While aspects of biological sex are similar across different cultures, aspects of gender may differ.
---Intersex - Various conditions that lead to atypical development of physical sex characteristics are collectively referred to as intersex conditions.
---Transgender persons have been documented in many indigenous, Western, and Eastern cultures and societies from antiquity until the present day. However, the meaning of gender nonconformity may vary from culture to culture.