The development of human sexual orientation remains a complex and multifaceted subject. It is often studied but its origins continue to elude us. In this preregistered study, our primary objective was to demonstrate the fraternal birth order effect (FBOE), which assumes a higher prevalence of older brothers in gay men than in their straight counterparts and which has also been recently recorded in lesbian women. Our second aim was to explore any potential impact of the FBOE on anal-erotic role orientation (AERO), both in gay and straight men. Our study sample included 693 gay men, 843 straight men, 265 lesbian women, and 331 straight women from Czechia and Slovakia. Employing a conventionally parameterized logistic regression model, we substantiated the FBOE among both gay men (OR = 1.35 for maternal older brothers) and lesbian women (OR = 1.71). These outcomes were confirmed by a more nuanced parameterization recently proposed by Blanchard (2022). Nonmaternal older brothers did not exhibit a significant influence on their younger brothers' sexual orientation. Contrary to some earlier reports, however, our data did not establish the FBOE as exclusive to gay men with the receptive AERO. Furthermore, our observations indicated a lower offspring count for mothers of gay men compared to mothers of straight men. Emphasizing the positive FBOE outcomes, we acknowledge the need for caution regarding the various options that can be used to estimate the familial influences on sexual orientation.

• MeSH
• dospělí MeSH
• heterosexualita statistika a číselné údaje   psychologie   MeSH
• homosexualita mužská * statistika a číselné údaje   psychologie   MeSH
• homosexualita ženská * statistika a číselné údaje   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• pořadí narození * MeSH
• sexuální a genderové menšiny statistika a číselné údaje   psychologie   MeSH
• sexuální chování statistika a číselné údaje   MeSH
• sourozenci MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Slovenská republika MeSH

One proposal for the persistence of homosexuality in the human population is the sexually antagonistic gene hypothesis, which suggests that the lower fertility of homosexual individuals, especially men, may be compensated by higher fertility of their relatives of the opposite sex. To test this hypothesis, we have collected data from 7,312 heterosexual men, 459 gay men, 3,352 heterosexual women, and 79 lesbian women mainly from Czechia. In an online survey, participants answered questions regarding their own as well as their parents' and grandparents' fertility. For men, we obtained no significant results except for higher fertility of gay men's paternal grandmothers, but the magnitude of this effect was very small. For the female sample, we recorded lower fertility of lesbian women's mothers and fathers. In line with our expectations, both gay men and lesbian women had lower fertility rates than their heterosexual counterparts. Our results are consistent with recent studies which likewise do not support the sexually antagonistic gene hypothesis.

• MeSH
• dospělí MeSH
• fertilita * genetika   MeSH
• heterosexualita * psychologie   MeSH
• homosexualita mužská * genetika   psychologie   statistika a číselné údaje   MeSH
• homosexualita ženská * genetika   psychologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• průzkumy a dotazníky MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

Disgust is an essential part of the behavioral immune system, protecting the individual from infection. According to the Compensatory Prophylaxis Hypothesis (CPH), disgust sensitivity increases in times of immunosuppression, potentially including pregnancy. We aimed to replicate a previous study observing longitudinal changes in disgust sensitivity in pregnant women. Additionally, for the first time, we explored how recent health problems influence these changes. To do this, we obtained disgust sensitivity measures from 94 women in each trimester and in early postpartum. In contrast to the original study, where disgust sensitivity was highest in the first trimester, we found that overall and animal reminder disgust increased across pregnancy and after birth. In line with the CPH, women who were recently sick in the first trimester had elevated disgust sensitivity at that time. Although disgust sensitivity was significantly higher in the second trimester and postpartum period compared to the first trimester in mothers pregnant with a male fetus, the overall results regarding the effect of fetus sex on disgust sensitivity were mixed. It seems that changing levels of disgust sensitivity during pregnancy and postpartum result from a suite of physiological and psychological changes that occur during this sensitive period of a woman's life.

• MeSH
• lidé MeSH
• odpor * MeSH
• poporodní období MeSH
• porod MeSH
• těhotenství MeSH
• těhotné ženy psychologie   MeSH
• trimestry těhotenství MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• homosexualita * MeSH
• lidé MeSH
• sexuální chování * MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• komentáře MeSH
• práce podpořená grantem MeSH

Latent infection of the globally spread parasite Toxoplasma gondii in humans has been associated with changes in personality and behavior. Numerous studies have investigated the effect of toxoplasmosis on depression, but their results are inconsistent. Our study focused on the effect of latent toxoplasmosis on depression in men and women in association with their fertility. In 2016-2018, we recruited clients (677 men and 664 women) of the Center for Assisted Reproduction and asked them to complete a standardized Beck Depression Inventory-II. In women without fertility problems, we found higher depression scores in Toxoplasma-positive than in Toxoplasma-negative (p = 0.010, Cohen's d = 0.48). Toxoplasma-positive infertile men, on the other hand, had lower depression scores than Toxoplasma-negative infertile men (p ≤ 0.001, Cohen's d = 0.48). Our results are consistent with the previously described effects of latent toxoplasmosis, which seem to go in opposite directions regarding the effect on personality and behavior of men and women. Our results could be explained by gender-contrasting reactions to chronic stress associated with lifelong infection. This suggests that due to gender differences in the impact of latent toxoplasmosis, future studies ought to perform separate analyses for women and men.

• Publikační typ
• časopisecké články MeSH

OBJECTIVES: The Sahel/Savannah belt is a region where two sympatric human subsistence strategies-nomadic pastoralism and sedentary farming-have been coexisting for millennia. While earlier studies focused on estimating population differentiation and genetic structure of this ecologically remarkable region's inhabitants, less effort has been expended on understanding the morphological variation among local populations. MATERIALS AND METHODS: To fill this gap, we used geometric morphometrics to analyze the facial features of three groups of pastoralists and three groups of sedentary farmers belonging to three language families (Niger-Congo, Nilo-Saharan, and Afro-Asiatic) whose mitochondrial DNA sequences have been published previously. RESULTS: Our results show that pastoralists differ from farmers with several facial features. We also found that individuals who bear maternally inherited haplotypes of Eurasian ancestry do not significantly morphologically differ from individuals whose maternal ancestry is sub-Saharan. CONCLUSIONS: Our study follows up and builds upon population genetic and phylogeographic studies of Eurasian haplogroups in the Fulani pastoralists and sub-Saharan haplogroups in the Arab pastoralists, as well as studies on the spread of lactase persistence mutations and other genetic markers. Our results suggest that recent gene flows across the Sahel/Savannah belt were not strong enough to erase a genetic structure established by Paleolithic foragers and further shaped by the adoption of agropastoral food-producing strategies.

• MeSH
• antropologie fyzická MeSH
• Arabové genetika   statistika a číselné údaje   MeSH
• běloši genetika   statistika a číselné údaje   MeSH
• černoši * genetika   statistika a číselné údaje   MeSH
• dieta statistika a číselné údaje   MeSH
• dospělí MeSH
• haplotypy genetika   MeSH
• lidé MeSH
• mitochondriální DNA genetika   MeSH
• mladý dospělý MeSH
• obličej anatomie a histologie   MeSH
• osoby s přechodným pobytem a migranti statistika a číselné údaje   MeSH
• populační genetika MeSH
• zemědělci statistika a číselné údaje   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• severní Afrika MeSH
• subsaharská Afrika MeSH

• MeSH
• biomechanika MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• matematika MeSH
• metody MeSH
• mladiství MeSH
• pružnost MeSH
• věkové faktory MeSH
• vývojová kyčelní dysplazie chirurgie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH