A systematic review published in Behavior Genetics (Springer) synthesizes the literature on twin studies concerning gender diversity, with the aim of quantifying the relative contribution of genetic and environmental factors.
The review collects and critically evaluates the twin studies published to date that address the concordance of diverse gender identity, applying explicit inclusion criteria and quality assessment. Both registry studies and individual case analyses are included.
The authors conclude that, overall, twin studies support the existence of a significant heritable component in gender diversity, with heritability estimates that vary according to the operational definition of the trait and the methodology employed. Non-shared environmental factors also play a relevant role.
The review highlights the methodological limitations of the literature, including small sample sizes, heterogeneity of criteria and selection bias, and proposes recommendations to standardize future studies.
It is a key reference for situating the state of knowledge on the genetic architecture of gender identity, and offers a rigorous framework for interpreting the findings of primary genetic association studies.
Bibliographic reference
Conabere W, et al. Genetic and Environmental Contributions to Gender Diversity: A Systematic Review of the Twin Literature. Behav Genet. 2025;55(5):339-359.
DOI: https://doi.org/10.1007/s10519-025-10231-3
PMID: 40938572
Publication access: the original reference can be consulted in open access or through the indicated DOI.
