Transmasculine refers to individuals assigned female at birth who identify with or express masculinity, while transfeminine describes those assigned male at birth who identify with or express femininity[1][2]. These umbrella terms encompass diverse identities including trans men, non-binary people, and gender-fluid individuals who align with masculine or feminine experiences respectively.
In contrast, cisgender individuals have a gender identity that aligns with their sex assigned at birth[3][4]. Cisgender men were assigned male at birth and identify as men, while cisgender women were assigned female at birth and identify as women. The prefix "cis" comes from Latin meaning "on the same side as," opposite to "trans" meaning "on the other side of"[3].
Gender identity development appears to have significant biological components. Research reveals that prenatal hormone exposure, particularly testosterone, plays a crucial role in brain sexual differentiation, which occurs during the second trimester of pregnancy[5][6]. This hormonal influence can affect gender identity and expression patterns throughout life[7][8].
Neuroimaging studies show distinct brain patterns in transgender individuals compared to cisgender controls. Transgender people exhibit unique features in brain regions associated with self-body perception, including differences in cortical thickness in the anterior cingulate-precuneus and right occipito-parietal cortex[9][10]. These findings suggest that gender identity may be partially determined by specific brain organization patterns that develop before birth[11][12].
Recent genetic research has identified associations between gender dysphoria and variations in sex hormone signaling genes. A landmark study of 380 transgender women found overrepresentation of specific alleles in genes including ERĪ±, SRD5A2, and STS, which are involved in hormone processing[13]. This suggests gender dysphoria may have an oligogenic component, with multiple genes contributing to its development[14].
Twin studies indicate heritability estimates ranging from 23-74% for gender identity variance, though these figures vary significantly across studies[12]. However, no single "transgender gene" has been identified, indicating the complexity of genetic influences on gender development.
Research with trans youth reveals three distinct developmental trajectories[15]:
Some youth report awareness of gender incongruence from early childhood and receive family support for exploration and expression. These individuals often transition socially at young ages with parental backing.
Others experience early gender questioning but face constraints that delay their ability to express their authentic gender until later in life, often due to family or social pressures.
Some individuals first become aware of gender dysphoria during or after puberty, though retrospective analysis often reveals earlier subtle signs.
These pathways demonstrate that gender identity development is non-linear and dynamic, involving both internal recognition and social expression processes[15].
Research comparing trans masculine and cisgender men reveals interesting patterns in adherence to masculine norms. Trans masculine individuals show higher scores on emotional control and self-reliance compared to cisgender men, while cisgender men score higher on heterosexual self-presentation and power over women[16]. This suggests trans masculine people may feel pressure to demonstrate certain aspects of masculinity more intensely, possibly as protection against discrimination.
Hegemonic masculinity represents culturally dominant forms of masculine expression that maintain male privilege and subordinate alternative masculinities[17]. Similarly, hegemonic femininity comprises characteristics like compliance, empathy, and nurturance that complement hegemonic masculinity and maintain gender hierarchies[18][19].
However, female masculinity and other non-normative gender expressions challenge these hegemonic forms[20][21]. Rather than being mere imitations of male masculinity, alternative masculinities reveal how gender is constructed and performed across different bodies and contexts.
Modern understanding recognizes that masculinity and femininity exist on spectrums rather than as binary categories[22][23]. Virtual reality research demonstrates how individuals can challenge traditional gender norms through avatar choices and digital self-expression, revealing the fluid nature of gender performance[23].
Psychological research shows that individuals can embody both masculine and feminine traits simultaneously - a concept known as psychological androgyny[24]. This challenges traditional binary thinking and suggests healthier, more flexible approaches to gender identity.
Social cognitive theory emphasizes how gender development occurs through observational learning, reinforcement, and cognitive processing[25][26]. Children learn gender norms through modeling others and receiving feedback from their environment, but they also actively construct their understanding rather than passively absorbing social messages.
Cultural background significantly shapes gender expression and perception[23]. What constitutes masculine or feminine behavior varies across societies and historical periods, demonstrating the socially constructed nature of gender norms while acknowledging biological influences.
For transgender individuals, psychological gender affirmation - an internal sense of valuing oneself and feeling satisfied with one's gender identity and expression - proves crucial for mental health[27]. Research consistently shows that gender-affirming care, including social transition and medical interventions when appropriate, improves wellbeing outcomes for trans youth and adults[15].
The existence of diverse gender identities and expressions challenges traditional binary systems that assume only two distinct, complementary genders exist. Transfamily theory suggests that families with transgender members must reconceptualize gender as more flexible and variable than previously understood[28].
Understanding trans-/cis- masculinity and femininity requires recognizing both the biological foundations and social constructions of gender. While prenatal hormones and genetics influence gender development, social experiences, cultural contexts, and individual agency also play crucial roles in shaping gender identity and expression throughout the lifespan.
This multifaceted understanding moves beyond simple nature vs. nurture debates to embrace the complex interplay of biological, psychological, and social factors that contribute to the rich diversity of human gender experience. As research continues, we gain deeper insights into how gender develops across different individuals and contexts, informing more inclusive and affirming approaches to supporting people of all gender identities.
