Abstract
Hamer et al. argue that the variable ever versus never had a same-sex partner does not capture the complexity of human sexuality. We agree and said so in our paper. But Hamer et al. neglect to mention that we also reported follow-up analyses showing substantial overlap of the genetic influences on our main variable and on more nuanced measures of sexual behavior, attraction, and identity.
Genetic research on sexuality had been constrained by the unavailability of samples large enough to achieve the statistical power required to detect variants with small effect sizes typical of complex traits. To address this, our study aimed to maximize statistical power in two ways: (i) combining the largest samples available with sexuality data from UK Biobank and 23andMe, and (ii) choosing the variable that yielded the largest effective sample size. Only the dichotomous variable we used in the main genome-wide association study (GWAS) satisfied both considerations. This variable we chose is straightforward and easy to understand, and was clearly described in the paper, including characterizing it as ever versus never had a same-sex partner as suggested by Hamer et al. (1). We made it clear that this variable did not capture the diversity and complexity of sexual behavior, and we did not intend or claim to measure sexual orientation or attraction with this variable. However, we reported follow-up analyses with subsets of the data and independent samples that showed overlap in the genetic signal for our main variable and for traditional measures of sexual orientation based on sexual attraction and identitycontrary to Hamer et al.s assertion that the study did not in fact investigate attraction or sexual orientation.
As is common for large-scale genetic studies, our analyses were constrained by the available phenotypic data, which were not collected for the particular purposes of our study. The UK Biobank, which comprised most of the available data, did not include sexual attraction or identity items. The only UK Biobank items relevant to sexual behavior were one question asking whether the participant had ever had a same-sex partner, and two questions asking their lifetime number of opposite-sex and same-sex partners (9% fewer respondents). Only the variable based on the dichotomous item maximized the absolute sample size. This variable also had the advantage of having an equivalent variable in the 23andMe sample (i.e., Other sex only response versus other responses to the question With whom have you actually had sex?). It also had a far greater effective sample size than the other dichotomous variables with a direct equivalent in 23andMe, namely restricting the non-heterosexual group to those who had only had same-sex partners, which in the UK Biobank can be derived from the items on numbers of same- and opposite-sex partners (effective UK Biobank sample size N = 53,688 for our main variable, versus N = 9775 when comparing heterosexuals with those who only had same-sex partners; effective sample size derived from the formula 4/[(1/Ngroup 1) + (1/Ngroup 2)].)
Without nuanced measures of behavior, fantasy, attraction, and identity in the large majority of our sample, our best option was to use the variable with maximal power available in the full sample (while acknowledging its limitations) and perform more nuanced follow-up analyses in subsets of the data to explore these important research questions about the complexity of sexuality. Hamer et al. seemingly disregard these follow-up analyses, which show evidence for substantial overlap in the genetic influences on sexual behavior with the kinds of measures that Hamer et al. recommend. First, in the UK Biobank there was a genetic correlation between our main dichotomous variable and a continuous variable measuring the proportion of total partners who were same-sex partners [rg = 0.92; supplementary materials of (2), p. 12]. Second, the 23andMe data included Klein scales for sexual fantasy, identity, attraction, and behavior, and these measures were genetically correlated with the main dichotomous measure in the UK Biobank [rg = 0.83, 0.79, 0.75, and 0.70, respectively; table S5 of (2)]. Third, we replicated three single-nucleotide polymorphisms identified by the main GWAS in a much smaller independent sample [MGSOSO; table S10 of (2)] whose comparison groups were predominantly heterosexual and predominantly homosexual individuals, per self-reported identity and feelings. Fourth, polygenic scores based on the main GWAS significantly predicted the identity-based groups in MGSOSO [table S12 of (2)] and continuous measures of same- versus opposite-sex attraction in two other small independent samples of young adults [Add Health and CATSS; tables S13 and S14 of (2)]. So, again, although we did not intend or claim to measure sexual identity or attraction with our main dichotomous variable, follow-up analyses showed that the genetic signal does substantially overlap for these phenotypes.
Responding to our suggestion that some of our findings cast doubt on popular measures of sexuality, Hamer et al. contend that genetic research cannot inform sexology research and that such an idea is an inversion of the scientific process. We disagree with this contention. To suggest that either sexology research or genetic research has supremacy in scientific enquiry is misguided. Both sexology research and genetic research can and should inform each other. Our genetic analyses revealed insights into the underlying structure of variation in sexual behavior that could not have been obtained using traditional methods of sexology researchfor example, that there is partial overlap in the influences on male and female sexual behavior.
The traditional and most popular measure of sexual orientation is the Kinsey scale (Fig. 1), which is bipolar and implies a continuum between exclusive heterosexuality and exclusive homosexuality, measuring the relative incidence of a composite of same-sex versus opposite-sex sexual behavior and psychological responses (not simply preference, as claimed by Hamer et al.). A concern with the Kinsey scale is that it inappropriately measures homosexuality and heterosexuality on a single dimensional scale, making one trade-off of the other (3). This enforced trade-off would not be a problem if it reflected the true underlying structure of individual variation in sexuality, such that the amount of same-sex behavior (and/or psychological responses) were indeed perfectly inverse to their opposite-sex counterparts. However, other research suggests that this is not the case (46). Individuals can be high on both same-sex and opposite-sex behavior or attraction (some bisexual individuals), and individuals can be low on both (asexual). This variation is not captured by a bipolar scale. Our findings (2) reinforced the point at the genetic level: The genetic variants that increase the likelihood of having had any (versus no) same-sex partners do not increase the likelihood of having a greater (versus lesser) proportion of total partners who are same-sex partners. That is, on the genetic level, there is no one continuum from exclusively opposite-sex to exclusively same-sex behavior. The 23andMe data showed genetic correlations (rg = 0.83 to 1.0) of same-sex behavior with attraction and fantasy [figure S7 of (2)], which suggests that the finding on same-sex sexual behavior might extend to these other aspects of sexuality too. For future genetic research on sexuality, if the phenotypic measure does not reflect the structure of the underlying genetic influences, then the precision and accuracy of the findings will be impaired. For this reason, we, like others [e.g., (35, 79)], suggest that sexual attraction, behavior, and feelings toward men and women be measured separately in future research.
The ratings are based on both psychologic reactions and overt experience. [Source: figure 161 of (10)]
Although we would much prefer even massive biobank-based samples to have deep phenotyping on our topic of interest (i.e., sexuality measures), data of this nature are not currently available. Generally, there is a practical trade-off between phenotypic detail and sample size. Our approach was to acknowledge the limitations but make reasoned use of the available data to move the field forward, recognizing that others may prefer to avoid examining such datasets altogether. In any event, we share Hamer et al.s concern to minimize public confusion, which is why we liaised with community groups on reporting and communication strategy, provided lay-oriented explanatory boxes 1 and 2 in our manuscript, developed a companion educational website (www.geneticsexbehavior.info), welcomed the public posting of alternative perspectives and concerns about our work (www.broadinstitute.org/news/perspectives-complex-genetics-same-sex-sexual-behavior), and held an informational press conference.
R. L. Sell, in The Health of Sexual Minorities: Public Health Perspectives on Lesbian, Gay, Bisexual and Transgender Populations, I. H. Meyer, M. E. Northridge, Eds. (Springer, 2007), pp. 355374.
A. C. Kinsey, W. B. Pomeroy, C. E. Martin, Sexual Behavior in the Human Male (Saunders, 1948).
See the article here:
Response to Comment on Large-scale GWAS reveals insights into the genetic architecture of same-sex sexual behavior - Science Magazine
- Copy number variation of the restorer Rf4 underlies human selection ... - Nature.com - November 15th, 2023 [November 15th, 2023]
- NYU Langone Health in the NewsThursday, November 9, 2023 - NYU Langone Health - November 15th, 2023 [November 15th, 2023]
- Eugenics: Plaguing scientific community with dark history | Opinion ... - The Arkansas Traveler - November 15th, 2023 [November 15th, 2023]
- Cranberries can bounce, float and pollinate themselves: The saucy ... - Japan Today - November 15th, 2023 [November 15th, 2023]
- Government Housing Assistance Linked to Increased Cancer ... - HealthDay - November 15th, 2023 [November 15th, 2023]
- Rate of New Lung Cancer Cases Has Decreased Over Last Five Years - HealthDay - November 15th, 2023 [November 15th, 2023]
- Clinically relevant antibiotic resistance genes are linked to a limited ... - Nature.com - November 15th, 2023 [November 15th, 2023]
- Disparities in Guideline-Concordant Care Found for Black CRC ... - HealthDay - November 15th, 2023 [November 15th, 2023]
- Mathematician Heather Harrington is new director at the Max Planck ... - EurekAlert - November 15th, 2023 [November 15th, 2023]
- New study finds genetic testing can effectively identify patients with ... - EurekAlert - November 15th, 2023 [November 15th, 2023]
- STK11 loss leads to YAP1-mediated transcriptional activation in ... - Nature.com - November 15th, 2023 [November 15th, 2023]
- CRISPR-broad: combined design of multi-targeting gRNAs and ... - Nature.com - November 15th, 2023 [November 15th, 2023]
- Master regulator of the dark genome greatly improves cancer T-cell ... - Science Daily - November 15th, 2023 [November 15th, 2023]
- Omega Therapeutics Showcases Bidirectional and Multiplexed ... - BioSpace - November 15th, 2023 [November 15th, 2023]
- Today is International 15q Day - ASBMB Today - November 15th, 2023 [November 15th, 2023]
- Evolution of taste: Sharks were already able to perceive bitter ... - EurekAlert - November 15th, 2023 [November 15th, 2023]
- Stanford Scientists Uncover New Indicators of Health, Disease, and ... - SciTechDaily - October 16th, 2023 [October 16th, 2023]
- NHGRI Director Eric Green elected to the National Academy of ... - National Human Genome Research Institute - October 16th, 2023 [October 16th, 2023]
- Monkey survives for two years after gene-edited pig-kidney transplant - Nature.com - October 16th, 2023 [October 16th, 2023]
- Opinion: Interest in RNA Editing Accelerates as Therapies Approach ... - BioSpace - October 16th, 2023 [October 16th, 2023]
- Regulation of dermal fibroblasts by human neutrophil peptides ... - Nature.com - October 16th, 2023 [October 16th, 2023]
- Consistent effects of the genetics of happiness across the lifespan ... - Nature.com - October 16th, 2023 [October 16th, 2023]
- Storytelling through the looking glass of genetics The Stute - The Stute - October 16th, 2023 [October 16th, 2023]
- Pet dogs shed light on human health, researchers say - UPI News - October 16th, 2023 [October 16th, 2023]
- Native microbiome dominates over host factors in shaping the ... - Nature.com - October 16th, 2023 [October 16th, 2023]
- Illinois-led project to sequence soybean genomes, improve future ... - Herald-Whig - October 16th, 2023 [October 16th, 2023]
- Unrealized targets in the discovery of antibiotics for Gram-negative ... - Nature.com - October 16th, 2023 [October 16th, 2023]
- How Biotech And AI Are Transforming The Human - Noema Magazine - October 16th, 2023 [October 16th, 2023]
- The Many Lives of Alexandria Forbes - BioSpace - October 16th, 2023 [October 16th, 2023]
- CEP20 promotes invasion and metastasis of non-small cell lung ... - Nature.com - October 16th, 2023 [October 16th, 2023]
- Genotyping, sequencing and analysis of 140,000 adults from Mexico ... - Nature.com - October 16th, 2023 [October 16th, 2023]
- The role and impact of alternative polyadenylation and miRNA ... - Nature.com - October 16th, 2023 [October 16th, 2023]
- Human - Simple English Wikipedia, the free encyclopedia - January 30th, 2023 [January 30th, 2023]
- Deep Dive Ties Together Dog Genetics, Brain Physiology and Behavior to Explain Why Collies Are Different from Terriers - Scientific American - December 12th, 2022 [December 12th, 2022]
- How oxytocin drives connections of newly integrated adult-born neurons: Research - Hindustan Times - December 12th, 2022 [December 12th, 2022]
- Alzheimer's Disease Genetics Fact Sheet - National Institute on Aging - December 2nd, 2022 [December 2nd, 2022]
- Human genetic clustering - Wikipedia - November 23rd, 2022 [November 23rd, 2022]
- Human Genome Project Fact Sheet - November 23rd, 2022 [November 23rd, 2022]
- Abstracts | International Congress of Human Genetics 2023 - November 23rd, 2022 [November 23rd, 2022]
- Ancient DNA and Neanderthals | The Smithsonian Institution's Human ... - November 16th, 2022 [November 16th, 2022]
- Biological Influences on Human Behavior: Genetics & Environment - November 16th, 2022 [November 16th, 2022]
- Fluent BioSciences showcasing breakthrough solutions to enable unprecedented scale, cost-efficiency and access for single-cell RNA sequencing at the... - October 28th, 2022 [October 28th, 2022]
- Human behaviour genetics - Wikipedia - October 23rd, 2022 [October 23rd, 2022]
- Nucleome Therapeutics raises oversubscribed 37.5 million Series A financing to decode the dark matter of the human genome and deliver first-in-class... - October 19th, 2022 [October 19th, 2022]
- Gladstone data scientist elected to the National Academy of Medicine - EurekAlert - October 19th, 2022 [October 19th, 2022]
- Ocugen to Host R&D Day in New York City on Tuesday, November 1, 2022 - Yahoo Finance - October 19th, 2022 [October 19th, 2022]
- Pharmacy researcher earns $2.3 million NIH award to study opioid addiction - EurekAlert - October 19th, 2022 [October 19th, 2022]
- Study shows age often plays a bigger role than genetics in gene expression and susceptibility to disease - Anti Aging News - October 19th, 2022 [October 19th, 2022]
- CSRWire - Direct Relief, Amgen and C/Can Team Up To Improve Access to Breast Cancer Diagnostics and Treatment in Paraguay - CSRwire.com - October 19th, 2022 [October 19th, 2022]
- Maze Therapeutics Appoints Harold Bernstein, M.D., Ph.D., as President, Research and Development and Chief Medical Officer - Business Wire - October 19th, 2022 [October 19th, 2022]
- New Rare Disease Therapy Effectively Lowers Plasma Phe in Patients with PKU - MD Magazine - October 19th, 2022 [October 19th, 2022]
- GSK : announces expanded collaboration with Tempus in precision medicine to accelerate R&D - Marketscreener.com - October 19th, 2022 [October 19th, 2022]
- Famous Scientific Discoveries That Changed the Course of History - 24/7 Wall St. - October 19th, 2022 [October 19th, 2022]
- Construction workers seek fulfilment of their demands - Star of Mysore - October 19th, 2022 [October 19th, 2022]
- Genetics | The Smithsonian Institution's Human Origins Program - October 13th, 2022 [October 13th, 2022]
- Genetics - Wikipedia - October 13th, 2022 [October 13th, 2022]
- Study looking at human genetics and Covid vaccine immune responses - Science Media Centre - October 13th, 2022 [October 13th, 2022]
- ASHG 2022 in Los Angeles brings together researchers from around the world to advance discoveries in genetics, genomics research - EurekAlert - October 13th, 2022 [October 13th, 2022]
- Maze Therapeutics Appoints Harold Bernstein, M.D., Ph.D., as President, Research and Development and Chief Medical Officer - Yahoo Finance - October 13th, 2022 [October 13th, 2022]
- The Age of the Pangenome Dawns - DNA Science - PLOS - October 13th, 2022 [October 13th, 2022]
- Influence of the microbiome, diet and genetics on inter-individual variation in the human plasma metabolome - Nature.com - October 13th, 2022 [October 13th, 2022]
- Genome editing technologies: final conclusions of the re-examination of Article 13 of the Oviedo Convention - Council of Europe - October 13th, 2022 [October 13th, 2022]
- Global Biobank Meta-analysis Initiative making genome-wide association studies more diverse and representative - EurekAlert - October 13th, 2022 [October 13th, 2022]
- New NHS genetic testing service could save thousands of children in England - The Guardian - October 13th, 2022 [October 13th, 2022]
- Covid protection may be boosted by genes, study shows - Yahoo News Australia - October 13th, 2022 [October 13th, 2022]
- Genomics in Cancer Care Market is estimated to be US$ 72.61 billion by 2032 with a CAGR of 16.3% during the forecast period 2032 - By PMI -... - October 13th, 2022 [October 13th, 2022]
- Identification of hub genes and candidate herbal treatment in obesity through integrated bioinformatic analysis and reverse network pharmacology |... - October 13th, 2022 [October 13th, 2022]
- Our *Homo sapiens* ancestors shared the world with Neanderthals, Denisovans and other types of humans whose DNA lives on in our genes -... - October 8th, 2022 [October 8th, 2022]
- Blue Eyed People Have a Single Ancestor | History of Yesterday - History of Yesterday - October 6th, 2022 [October 6th, 2022]
- Heart infection could be cause of death of Polish, US hero - ABC News - October 6th, 2022 [October 6th, 2022]
- 23andMe Announces Trials-in-Progress Poster Presentation on 23ME-00610, An Investigational Antibody Targeting CD200R1, at The Society for... - October 6th, 2022 [October 6th, 2022]
- The Genetic Drivers Of Longevity In Mice, Humans And Worms - Science 2.0 - October 6th, 2022 [October 6th, 2022]
- ANGPTL7, a therapeutic target for increased intraocular pressure and glaucoma | Communications Biology - Nature.com - October 6th, 2022 [October 6th, 2022]
- 'Neanderthal Man' Nobel Prize winner Svante Pbo revolutionized anthropology. Here is a look back at his groundbreaking 2014 memoir - Genetic Literacy... - October 6th, 2022 [October 6th, 2022]
- Understanding Human Genetic Variation - NCBI Bookshelf - September 14th, 2022 [September 14th, 2022]
- Genetics - National Institute of General Medical Sciences (NIGMS) - September 14th, 2022 [September 14th, 2022]
- People with ME invited to take part in major genetic study - The Independent - September 14th, 2022 [September 14th, 2022]
- Ketamine Promising for Rare Condition Linked to Autism - Medscape - September 14th, 2022 [September 14th, 2022]
- How a small, unassuming fish helps reveal gene adaptations - University of Wisconsin-Madison - September 14th, 2022 [September 14th, 2022]
- How Nutrigenomics Explores Links Between Nutrition And Genes - Health Digest - September 14th, 2022 [September 14th, 2022]