Abstract
The sexually antagonistic gene hypothesis (SAGH) for male androphilia posits that genes associated with androphilia (i.e., sexual attraction to adult males) will result in lowered reproduction when present in males, but increased reproduction when present in females. Findings derived from some Western European samples furnish support for the SAGH; however, results from studies conducted in other regions of the world have been more equivocal. Our previous research in Samoa indicated that the mothers as well as the maternal and paternal grandmothers of androphilic males (known locally as fa’afafine) exhibit elevated reproductive output when compared to the relatives of gynephilic men (i.e., males that are sexually attracted to adult females). The present replication study tested the SAGH in Samoa using a sample that was 122 % larger than the one previously studied by our group (VanderLaan, Forrester, Petterson, & Vasey, 2012). In line with the predictions of the SAGH, we hypothesized that the grandmothers, aunts, and mothers of fa’afafine would show elevated reproductive output compared to those of Samoan gynephilic men. Data were collected from 191 fa’afafine and 191 gynephilic men on the reproductive output of their paternal and maternal biological relatives (i.e., mothers, grandmothers, aunts, uncles). The mothers and maternal grandmothers of fa’afafine showed elevated reproductive output compared to those of gynephilic men. The paternal grandmother effect was not replicated. Although these results are consistent with the SAGH, a lack of difference in the reproductive output of aunts renders support for the SAGH in Samoa equivocal.
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Notes
Previously reported data from Samoa (VanderLaan et al., 2012) had sufficient power to detect effects of d = .43 or higher, using α = .05, and power level of 80 %. The present sample represents an improvement over this, as it had sensitivity to detect effects of d = .28 or higher, given 80 % power, and α = .05 (calculated with G*Power, see Faul, Erdfelder, Lang, & Buchner, 2007).
The application of these exclusion rules, as well as the fact that not all probands had kin in each relevant category, explains sample size variation (n) for comparisons shown in Table 2.
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Acknowledgments
SWS and LJP were funded by Social Sciences and Humanities Research Council of Canada (SSHRC) CGS–Masters Scholarships. DPV was funded by a Natural Sciences and Engineering Research Council of Canada (NSERC) Doctoral Award. PLV was funded by the University of Lethbridge, a Canadian Institute of Health Research Catalyst Grant, an NSERC Discovery Grant, and an Alberta Innovates-Health Solutions Grant. All authors declare that no conflicts of interest exist that would impact or impede the publication of this research. This research was presented at the Puzzle of Sexual Orientation Conference, which was held during July 20–23, 2015, in Lethbridge, Alberta, Canada.
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Semenyna, S.W., Petterson, L.J., VanderLaan, D.P. et al. A Comparison of the Reproductive Output Among the Relatives of Samoan Androphilic Fa’afafine and Gynephilic Men. Arch Sex Behav 46, 87–93 (2017). https://doi.org/10.1007/s10508-016-0765-8
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DOI: https://doi.org/10.1007/s10508-016-0765-8