The Autodidactic Universe: An approach to cosmology in which the Universe learns its own physical laws

The Autodidactic Universe. Stephon Alexander, William J. Cunningham, Jaron Lanier, Lee Smolin, Stefan Stanojevic, Michael W. Toomey, Dave Wecker. arXiv Sep 2 2021. https://arxiv.org/abs/2104.03902

Abstract: We present an approach to cosmology in which the Universe learns its own physical laws. It does so by exploring a landscape of possible laws, which we express as a certain class of matrix models. We discover maps that put each of these matrix models in correspondence with both a gauge/gravity theory and a mathematical model of a learning machine, such as a deep recurrent, cyclic neural network. This establishes a correspondence between each solution of the physical theory and a run of a neural network. This correspondence is not an equivalence, partly because gauge theories emerge from N→∞ limits of the matrix models, whereas the same limits of the neural networks used here are not well-defined. We discuss in detail what it means to say that learning takes place in autodidactic systems, where there is no supervision. We propose that if the neural network model can be said to learn without supervision, the same can be said for the corresponding physical theory. We consider other protocols for autodidactic physical systems, such as optimization of graph variety, subset-replication using self-attention and look-ahead, geometrogenesis guided by reinforcement learning, structural learning using renormalization group techniques, and extensions. These protocols together provide a number of directions in which to explore the origin of physical laws based on putting machine learning architectures in correspondence with physical theories. 

In high-income countries, relation of women’s labor force participation & fertility is now positive; father contribution rates to child-raising are more important for fertility; & fathers seem most interested in children in Norway, the least in Russia

The Economics of Fertility: A New Era. Matthias Doepke, Anne Hannusch, Fabian Kindermann & Michèle Tertilt. NBER Working Paper 29948. Apr 2022. DOI 10.3386/w29948

Abstract: In this survey, we argue that the economic analysis of fertility has entered a new era. First-generation models of fertility choice were designed to account for two empirical regularities that, in the past, held both across countries and across families in a given country: a negative relationship between income and fertility, and another negative relationship between women's labor force participation and fertility. The economics of fertility has entered a new era because these stylized facts no longer universally hold. In high-income countries, the income-fertility relationship has flattened and in some cases reversed, and the cross-country relationship between women's labor force participation and fertility is now positive. We summarize these new facts and describe new models that are designed to address them. The common theme of these new theories is that they view factors that determine the compatibility of women's career and family goals as key drivers of fertility. We highlight four factors that facilitate combining a career with a family: family policy, cooperative fathers, favorable social norms, and flexible labor markets. We also review other recent developments in the literature, and we point out promising new directions for future research on the economics of fertility.

---

h/t Tyler Cowen https://marginalrevolution.com/marginalrevolution/2022/04/new-developments-in-the-economics-of-fertility.html : Another result is that quality vs. quantity tradeoff models for children no longer perform very well.  And fertility-education relationships are greatly weakened, just as the income-fertility relationships are.  The marketization of childcare is likely an important cause of this shift.

Italy and Spain are two countries where the income-fertility relationship is not being reversed.

Father contribution rates to child-raising are growing in importance for fertility.  Fathers seem most interested in their children in Norway, and least interested in Russia, of the countries sampled.

If a couple disagrees on having another kid, the chance they do is relatively small.

In Denmark in 2015, six percent of all births occurred with some kind of medical help related to conception.

There are now positive correlations between public childcare provision, though I do not in this paper see any reliable causal estimate.

The paper has a section on social norms, but it oddly fails to consider religion.

There is some evidence for peer effects mattering for fertility, for instance in a workplace.

21% of autosomal DNA in eastern chimpanzees derives from western chimpanzee introgression & all four chimpanzee lineages share a common ancestor about 987,000 y ago (much earlier than thought), with a male reproductive & dispersal skew

Estimating bonobo (Pan paniscus) and chimpanzee (Pan troglodytes) evolutionary history from nucleotide site patterns. Colin M. Brand et al. Proceedings of the National Academy of Sciences, April 22, 2022 | 119 (17) e2200858119 | https://doi.org/10.1073/pnas.2200858119

Significance: There is genomic evidence of widespread admixture in deep time between many closely related species, including humans. Our closest living relatives, bonobos and chimpanzees, may also exhibit such patterns. However, assessing the exact degree of interbreeding remains challenging because previous studies have resulted in multiple inconsistent demographic models. We use an approach that addresses these gaps by analyzing all lineages, simultaneously estimating parameters, and comparing previously models. We find evidence of considerable introgression from western into eastern chimpanzees. We also show more breeding females than males and evidence of male-biased dispersal in western chimpanzees. These findings highlight the extent of admixture in bonobo and chimpanzee evolutionary history and are consistent with substantial differences between past and present chimpanzee biogeography.

Abstract: Admixture appears increasingly ubiquitous in the evolutionary history of various taxa, including humans. Such gene flow likely also occurred among our closest living relatives: bonobos (Pan paniscus) and chimpanzees (Pan troglodytes). However, our understanding of their evolutionary history has been limited by studies that do not consider all Pan lineages or do not analyze all lineages simultaneously, resulting in conflicting demographic models. Here, we investigate this gap in knowledge using nucleotide site patterns calculated from whole-genome sequences from the autosomes of 71 bonobos and chimpanzees, representing all five extant Pan lineages. We estimated demographic parameters and compared all previously proposed demographic models for this clade. We further considered sex bias in Pan evolutionary history by analyzing the site patterns from the X chromosome. We show that 1) 21% of autosomal DNA in eastern chimpanzees derives from western chimpanzee introgression and that 2) all four chimpanzee lineages share a common ancestor about 987,000 y ago, much earlier than previous estimates. In addition, we suggest that 3) there was male reproductive skew throughout Pan evolutionary history and find evidence of 4) male-biased dispersal from western to eastern chimpanzees. Collectively, these results offer insight into bonobo and chimpanzee evolutionary history and suggest considerable differences between current and historic chimpanzee biogeography.

Parental sexual orientation and gender identity do not in themselves determine success in parenting or child development: Sexual & gender minority parents & their children have shown remarkable resilience, even in the face of many challenges

Parental sexual orientation, parental gender identity, and the development of children. Charlotte J. Patterson. Advances in Child Development and Behavior, April 22 2022. https://doi.org/10.1016/bs.acdb.2022.03.002

Abstract: In recent years, many lesbian, gay, bisexual, transgender, and queer (LGBTQ) adults have become parents. LGBTQ parenthood does, however, remain a controversial topic across the United States and around the world. Several questions have been raised. For instance, to what extent do LGBTQ adults make capable parents? Do children who have LGBTQ parents grow up in healthy ways? What factors contribute to positive family functioning in families with LGBTQ parents? A growing body of social science research has addressed these questions, and the findings suggest both that LGBTQ adults are successful in their roles as parents and that their children develop in positive ways. Overall, the findings to date suggest that parental sexual orientation and gender identity do not in themselves determine success in parenting or child development; indeed, sexual and gender minority parents and their children have shown remarkable resilience, even in the face of many challenges. Contextual issues, as well as implications of research findings for law and policy around the world are discussed.

Keywords: Sexual orientationParentLesbianGayBisexualTransgenderGender identity

Investigating the Pink Tax: Evidence Against a Systematic Price Premium for Women in personal care products

Moshary, Sarah and Tuchman, Anna and Bhatia, Natasha, Investigating the Pink Tax: Evidence Against a Systematic Price Premium for Women in CPG (December 16, 2021). SSRN: http://dx.doi.org/10.2139/ssrn.3882214

Abstract: This paper provides evidence on price disparities for personal care products targeted at different genders using a national dataset of grocery, convenience, drugstore, and mass merchandiser sales. We find that women’s products are more expensive in some categories (e.g., deodorant) but less expensive in others (e.g., razors). Further, in an apples-to-apples comparison of women’s and men’s products with similar ingredients, the women’s variant is less expensive in three out of five categories. Our results call into question the need for and efficacy of recently proposed and enacted legislation mandating price parity across gendered products.

Keywords: Price Discrimination, Gender, Pink Tax

JEL Classification: L66, M31, D63

Poorly governing ethnic parties persist because core supporters remain loyal in the face of poor governance because of dignity concerns, and are most likely to forgive ethnic parties for failing to address bread-and-butter issues

Malik, Mashail, Discrimination & Defiant Pride: How the Demand for Dignity Can Create Slack for Poor Governance (February 24, 2022). SSRN: http://dx.doi.org/10.2139/ssrn.4043185

Abstract: Why do poorly governing ethnic parties persist? Dominant approaches to ethnic voting explain this persistence by arguing that core supporters receive material benefits in exchange for loyal support. In this paper, I argue that within-group variation in continued support for ethnic parties is not explained by such instrumental theories. Instead, I show that core supporters remain loyal in the face of poor governance because of dignity concerns. Those in-group members who face more discrimination from state arms dominated by other ethnic groups are also those who place a higher value on the provision of group status through descriptive representation. As a result, these subgroups are also more willing to trade-off good governance with descriptive representation. This creates a perverse incentive for ethnic parties to under-serve their most loyal supporters. Because individuals from lower social classes are more exposed to state discrimination, this means that those who would benefit most from improvements in public goods and services are also (1) least likely to see these improvements, and (2) most likely to forgive ethnic parties for failing to address bread and-butter issues. This argument is supported by ethnographic, descriptive, and experimental evidence from the megacity of Karachi, Pakistan.

The sexes do not differ in general intelligence, but they do in some specifics: Female advantages in writing, male advantages at higher math ability levels

The sexes do not differ in general intelligence, but they do in some specifics. Matthew R.Reynolds, Daniel B. Hajovsky, Jacqueline M. Caemmerer. Intelligence, Volume 92, May–June 2022, 101651. https://doi.org/10.1016/j.intell.2022.101651

Highlights

• Despite no differences in general intelligence, there are sex differences in specific abilities.

• Reliable and meaningful female advantages are found in processing speed and writing.

• Reliable and meaningful male advantages are found in visual processing.

• Sex differences research should consider construct breadth and moving beyond mean differences only.

Abstract: Reliable and meaningful sex differences exist in specific cognitive abilities despite no reliable or meaningful sex difference in general intelligence. Here we use Cattell-Horn-Carroll (CHC) theory to highlight research findings related to sex differences in intelligence, with a focus on studies of test scores from comprehensive intelligence measures that were obtained from large and representative samples of children and adolescents. Female advantages in latent processing speed and male advantages in latent visual processing are the most meaningful and consistently reported sex differences regarding CHC broad cognitive abilities. Differences have been reported in narrow and specific ability constructs such as mental rotation and object memory location. In academic achievement, the largest and most consistent findings are female advantages in writing, whereas male advantages at higher math ability levels are also found. Empirical descriptions of sex differences should consider the breadth of the construct under study and incorporate analysis beyond simple mean differences. Score analysis methods that utilize multiple-group confirmatory factor models and multiple-indicator multiple cause models are useful to address the former, and analysis methods such as quantile regression and male-female ratio calculations along score distributions are useful to address the latter. An understanding of why specific ability differences exist in combination and in the presence of similarities will improve researchers' understanding of human cognition and educational achievements.

Keywords: Sex differencesCattell-Horn-Carroll theoryIntelligenceHuman cognitive abilities

Three accounts of the cognitive abilities that facilitated the emergence and transmission of cumulative culture in the recent hominin lineage

Henrich, Heyes and Tomasello on the Cognitive Foundations of Cultural Evolution. Cecilia Heyes. September 13 2021. To appear in: The Oxford Handbook of Cultural Evolution, Eds. Rachel Kendal, Jamie Tehrani & Jeremy Kendal. https://users.ox.ac.uk/~ascch/Celia's%20pdfs/Heyes%20&%20Moore%20AAC%20pdf.pdf

Abstract: We give a brief overview of three accounts of the cognitive abilities that facilitated the emergence and transmission of cumulative culture in the recent hominin lineage. These accounts were developed by Joseph Henrich (e.g., 2015), Cecilia Heyes (e.g., 2018), and Michael Tomasello (e.g., 1999, 2008, 2014) in collaboration with others. We pay particular attention to the different abilities that these authors think are foundational to human cultural evolution, and to questions about whether these abilities first arose as products of genetic or cultural evolution. Our hope is that by clarifying the similarities and differences between these accounts, we will identify points of disagreement that could be tested empirically, and areas where further conceptual clarification is required.

Keywords: cultural evolution, cultural learning, human cognition, adaptations, Henrich, Heyes, Tomasello

Very small advantage of the religious: When comparing a maximally nonreligious atheist group against several maximally religiously affiliated groups, atheists largely showed health parity

Throw BABE Out With the Bathwater? Canadian Atheists are No Less Healthy than the Religious. David Speed. Journal of Religion and Health, Apr 18 2022. https://link.springer.com/article/10.1007/s10943-022-01558-w

Abstract: The belief-as-benefit effect (BABE) is a broad term for the positive association between religion/spirituality (R/S) and health outcomes. Functionally, religious variables and religious identities predict greater wellness, which implies that atheists should report worse health relative to religious groups. Using Cycle 29 of the cross-sectional General Social Survey from Statistics Canada (N > 15,900), I explored health differences in stress, life satisfaction, subjective physical wellbeing, and subjective mental wellbeing across R/S identities (atheists, agnostics, Nones, Catholics, Protestants, Eastern Religions). Results indicated that (1). religious attendance, prayer, and religiosity were generally unrelated to all health outcomes for all R/S identities, (2). averagely religious atheists reported health parity with averagely religious members of all other R/S identities, and (3). when comparing a maximally nonreligious atheist group against several maximally religiously affiliated groups, atheists largely showed health parity. If both low R/S and high R/S are associated with comparable wellness, researchers should actively question whether R/S is genuinely salutary.

Letters To A Spanish Youngster CCLXVII

Letters To A Spanish Youngster CCLXVII

[...]

Your Honor whose being so far from this humble being makes Your follower crushed by aprehension and pain, which at times seem to guiding him to the kingdom of death,/Su Señoría cuyo estar tan alejado de este humilde ser hace a Su seguidor aplastado por la congoja y el dolor, que parecen a veces conducirle al reino de la muerte,

I keep making good use of this poet, the young ibn Gabirol*:/Sigo haciendo uso de este poeta, el joven ibn Gabirol:

[To some Jacob/A un tal Jacob]

                                                      [Mi alma del miedo de amar agoniza,

                                                       [...]

                                                       De ir en su zaga mis juicios se hicieron endebles;

                                                       el hado me acosa

                                                       y yo estoy exangüe.

                                                       [...]

                                                       Estoy hastiado de mis pensamientos,

                                                       combato el tumulto de angustia que encierra mi alma

                                                       y estoy prosternado.

                                                       [...]

                                                       desde hace algún tiempo naufrago en un mar de torpeza.

                                                       ¿Quién es quien camina

                                                       en alas de mi alma

                                                       y planta en el huerto de amores un árbol

                                                       de amor?

                                                       [...]

                                                       Amigo, a ti vienen los versos más dulces:

                                                       con ellos se ablanda mi alma y se hiende.

                                                       Mi espíritu ofrezco en rescate de un canto de loa,

                                                       que surte de fuente preciada

                                                       y fluye de un río esplendente;

                                                       que cae cual rocío encima del heno;

                                                       retorna las almas de aquellos que son sus amantes

                                                       y así las redime de ir al sheol.

                                                       Le son de mis cantos los temas livianos;

                                                       pues tal es la altura de sus cualidades

                                                       que llega hasta el cielo.

                                                       [...]

                                                       Al ver frente a frente su cara, librose

                                                       mi alma que ayer expiraba.]

[On rab Nisim/Sobre rab Nisim]

                                                      [Acerca de mi alma preguntasteis

                                                       quién fuera su sustento;

                                                       y cuando las angustias aumentaron,

                                                       qué quien la mantenía.      Estabais asombrados

                                                       de que la golpearan las tristezas

                                                       y en pie se mantuviera, no logrando

                                                       la pena derribarla.

                                                       Que esto no os asombre: asombraos

                                                       de [Martin], que habita dentro de ella.

                                                       [...]

                                                       Vosotros, mis amigos      más íntimos, llevadle

                                                       saludos a mi amado;

                                                       la bendición reciba de un discípulo

                                                       en cuyos ojos es      más caro que su alma,

                                                       la cual ahora derrama en su presencia.

                                                       [...]

                                                       En ti cavilo siempre:

                                                       si tú fueras el uno,      yo te prolongaría;

                                                       malhaya si olvidara      mi alma tu alianza

                                                       y lloro sin descanso. [...]

                                                       Que paz en abundancia      y gracias tengas cerca

                                                       y tanta salvaguardia      que nadie la calcule.]

The "one" is a reference to "Yahweh is one," and to the reward that the tradition promises to those who extend "one" while making the declaration of faith./El uno es por la cláusula "Yahvé es uno", y el premio que la tradición asigna al que prolonga "uno" al recitar la profesión de fe.

[On rabbi Isaac's leaving/Ante la partida de rabí Isaac]

                                                      [Amigos míos,

                                                       suplicadle mi sueño:

                                                       quizás en sueños logre ver sus relámpagos.

                                                       [...]

                                                       lloremos por los días de adolescencia

                                                       como el mercador llora

                                                       la decadencia de los mercados.

                                                       [...]

                                                       Despojó el corazón de [muchos];

                                                       yo fui de los primeros que ha despojado.

                                                       [...]

                                                       De esperanza y de espera me dejó preso;

                                                       ¿quién me diera que fuera de sus librados?

                                                       [...]

                                                       ¿Y como va a dejar en mi seno el pago

                                                       de mi amor [...]?

                                                       Que justicia y clemencia son sus asiduos;

                                                       le amamantan la ciencia y el buen consejo.

                                                       Ojalá yo no sea sino el amigo

                                                       que retribuye el pago de los amores

                                                       y sus decretos.

                                                       Yo te elogio y tú eres el mismo elogio de mis palabras;

                                                       y un cuello tan hermoso que sus ollares

                                                       los engalana.]

[To a wise and powerful man/A un hombre sabio y poderoso]

                                                      [Exulta, alma mía, y en canto prorrumpa tu habla.

                                                       [...]

                                                       Arranca una rosa, un lirio desprende, un mirto desgaja;

                                                       [...]

                                                       Agarra en las manos un cáliz y un vaso

                                                       tomando al amado por suerte y fortuna

                                                       y huélgate estando los vates reunidos.

                                                       Exige alborozo; expulsa la pena; el júbilo excava;

                                                       [...]

                                                       Profiere alegría; en el campamento

                                                       el juicio aposenta. Adquiere sapiencia

                                                       y alumbra las faces de tu principal.

                                                       Entónale un cántico al noble varón

                                                       cumplido y excelso.

                                                       [...]

                                                       Y ¡qué esplendoroso, qué limpio y qué puro es su dicho!,

                                                       cabeza de honrados, alférez, señor de tu siglo.

                                                       [...]

                                                       Es árbol frondoso, plantel de delicias y fiel mensajero;

                                                       es dulce cual es el maná.

                                                       [...] tiene un rocío que alumbra el camino de todas sus

                                                                                                                           hablas.

                                                       [...] aunque es muy humilde,

                                                       se goza la luna de ser su sirviente.

                                                       [...] tiene la gracia del ciervo

                                                       y un bálsamo lleva en su boca.

                                                       [...]

                                                       Joyel son sus hablas

                                                       [...]

                                                       En el aposento de lo deleitable

                                                       él solo se yergue.

                                                       [...] se recubre

                                                       de luz cual de un manto.

                                                       El brillo del alba lo infunde su aspecto,

                                                       la luz de la luna la emana su lustre

                                                       y de sus destello proviene el destello.

                                                       Es bueno de acciones; humilde y modesto de espíritu;

                                                       [...]

                                                       Saberes expresa;

                                                       [...]

                                                       Su fruto codicias;

                                                       feliz tú si pones en él tu esperanza.

                                                       [...]

                                                       Es roja y radiante la luz del amado y hermano,

                                                       es gozo de aquel que suspira.

                                                       Exulta, alma mía, y en canto prorrumpa tu habla.]

Weeping gently for being so far from Your voice and body features as the merchant weeps for the failing market, Yours faithfully/Llorando suavemente por estar tan lejos de Su voz y formas corporales como el mercader llora por la decadencia de los mercados*, Suyo fielmente

                 a. r. ante Su Señoría

--

Notes

*  Adapted from Selected Poems of Solomon ibn Gabirol, translated by Peter Cole (Princeton, NJ: Princeton Univ. Press, 2001), & the Spanish version from Selomó ibn Gabirol—Poesía secular, by Elena Romero (Madrid: Alfaguara, 1978)

Sexual attraction to men as a risk factor for eating disorders: the role of mating expectancies and drive for thinness

Sexual attraction to men as a risk factor for eating disorders: the role of mating expectancies and drive for thinness. Pedro María Ruiz de Assin Varela, Jose Manuel Caperos & Elena Gismero-González. Journal of Eating Disorders volume 10, Article number: 52. Apr 15 2022. https://link.springer.com/article/10.1186/s40337-022-00576-z

Abstract

Background: Men tend to give more importance than women to physical aspects when selecting a partner; thus, the internalization of beauty standards and the ideal of thinness may be greater in populations attracted to men, placing them at a higher risk of eating disorders.

Methods: In a sample (n = 398) of heterosexual and gay men and women, we evaluated the drive for thinness, body dissatisfaction, and bulimic symptomatology. Using ANCOVAs, we analyzed the differences in symptoms score according to sex, sexual orientation and relational status including body mass index (BMI) as covariate; we also evaluated the mediating role of drive for thinness in the relationship between sexual orientation and body dissatisfaction.

Results: We found an increased drive for thinness and body dissatisfaction in men-attracted compared with women-attracted participants; also, body dissatisfaction was greater in women than in men. Heterosexual women presented higher bulimia scores than lesbian women. Gay men open to relationships presented higher drive for thinness and body dissatisfaction scores than those not-open to relationships. Finally, differences in body dissatisfaction between gay and heterosexual men were fully explained by drive for thinness, while, in the case of women, drive for thinness only partially explained these differences.

Conclusions: Attraction to men seems to be a risk factor for EDs in the case of gay men and heterosexual women. In addition, in the case of heterosexual women, other factors independent of the desire to attract men seem to be important.

Plain English summary: Eating disorders (EDs) are important and common diseases that affect different groups of people differently. Specifically, various studies show a higher prevalence of eating disorders in gay men and heterosexual women. This could be interpreted to be a result of their attraction to men, who tend to place a greater importance on physical attractiveness when looking for a partner. In this study, we compared different ED symptomatology (drive for thinness, body dissatisfaction, and bulimia) in a sample of heterosexual and gay men and women, addressing their relationship with sex, sexual orientation, and relational status. We found an increased drive for thinness and body dissatisfaction in men-attracted (gay men and heterosexual women) compared with women-attracted participants (heterosexual men and lesbian women); also, body dissatisfaction was greater in women than in men regardless of the sexual orientation. Finally, heterosexual women presented higher bulimia scores than lesbian women, and gay men open to relationships presented higher drive for thinness and body dissatisfaction scores than those not-open to relationships (and therefore less inclined to try to attract other people sexually). In summation, our results seem to support the idea that attraction to men seems to be a risk factor for EDs in the case of gay men and heterosexual women, although, in the case of women other factors that are independent of sexual orientation should also be important.

Discussion

Regarding the first aim of the study, and as previously described in the literature [7, 8, 12, 16], heterosexual women and gay men presented greater ED symptomatology than lesbian women and heterosexual men, but these differences depended on the specific symptomatology evaluated. In the case of drive for thinness, differences appeared in the men-attracted group, and, in this group, symptomatology was greater in men than women; Body dissatisfaction was greater in men-attracted participants regardless of their sex but was also higher in women regardless of their sexual orientation; Bulimia symptomatology was much greater in heterosexual than in lesbian women and was similar to men, regardless of their sexual orientation.

As proposed by Siever [27], ED risk may be partially driven by mating motivations. Given that men place more importance on body shape and physical features than women when choosing potential partners [26], people attracted to men may be under greater pressure to have an attractive physique, focusing on those aspects that are mainly considered to be attractive. The thin-ideal is typically the most widespread Western ideal of beauty [43]; and the internalization of thin-ideal places men-attracted people at risk of body dissatisfaction symptomatology. In recent years, the use of social media has been widely related to the exposure and internalization of such ideals [44,45,46,47,48]. Social networks affect the self-image of both men and women and, therefore, their idealized content serves as a comparison criterion for both sexes [49].

Gay men presented the highest drive for thinness scores of the four groups, higher than heterosexual women, suggesting a particular vulnerability to thin-ideal internalization. Some studies reported that bisexual and gay men are more susceptible than heterosexual men to social messages focusing on physical appearance [50] and place more importance on physical appearance and attractiveness [51]. Notably, Gigi et al. [50] found that they showed increased attention to social comparison information, increased internalization of cultural ideals presented in the media about appearance, and susceptibility to the influence of advertisements that emphasize appearance, which was interpreted as a consequence of interest to please other men. In this regard, Li et al. [30] reported that, when faced with a context of intrasexual competition, gay men reported more restrictive eating attitudes and more body image concerns than in non-competitive scenarios or than heterosexual men. According to the authors, contexts of intrasexual competition should elicit desires to be especially thin for many individuals given that intrasexual competition is established in relation to those characteristics that are desirable.

In the case of body dissatisfaction, on the one hand, we found a main effect of sexual orientation. Body dissatisfaction was higher in gay men than in heterosexual men, and also in heterosexual woman than in lesbian women. He et al. [52] analyzed 75 primary studies published between 1986 and 2019, finding that sexual minority men had a higher level of body dissatisfaction than heterosexual men (57 studies, 128 effect sizes), with small to medium effect sizes. This result partially support Siever’s view, as well as suggesting that the internalization of thin-ideal by women and gay men places men-attracted people at risk of body dissatisfaction symptomatology. Meanwhile, on the other hand, we also found a main effect of sex, with women presenting higher scores than men, regardless of their sexual orientation. In general, women are under greater sociocultural pressure of an aesthetic ideal and most studies reported a higher prevalence of body dissatisfaction in women [53]. Women, for example, have lower body satisfaction than men regardless of their BMI [54]. Up to 80% of women respondents expressed current dissatisfaction with their bodies [55], and body dissatisfaction was found to be the most potent predictor of EDs [56]. Social pressures mean that women see their appearance as a fundamental factor in their value as individuals and expect others to routinely examine them [57]. This may lead them to scrutinize their body image, increasing the risk of being dissatisfied with it [58, 59].

In the case of bulimia, lesbian women reported the lowest bulimia scores, being much lower than heterosexual women, while for men there were no differences based on sexual orientation. Higher body dissatisfaction was found to be a predictor of bulimia [53]. Gay men also presented high levels of body dissatisfaction; however, this did not translate into a high rate of reported bulimia symptomatology. Given that gay men still emphasize the importance of a lean but also athletic physique, with a low percentage of body fat [51, 60, 61], it seems logical that they would seek to minimize behaviors contrary to that ideal. In this sense, some authors already propose that for men, sexual attraction to men would only be a risk factor for restrictive eating symptomatology [14, 29]. Although there are others who continue to find significant differences in measures of bulimia or impulse regulation [33].

Lesbian women presented the lowest bulimia symptomatology. This result is in line with other studies suggesting that, in women, a lesbian sexual orientation would be a protective factor against EDs [12], being associated with lower body dissatisfaction [16, 17]. However, similar research has yielded contradictory results: Dotan et al. [62], in a recent meta-analysis examining the association between sexual orientation and disordered eating in women, reported that there was no significant difference in overall disordered eating between lesbians and heterosexual women, however, lesbians reported restricting less and bingeing more than heterosexual women.

The second aim of our study was to evaluate the effect of relationship status on ED symptomatology. According to Siever’s hypothesis, a greater symptomatology would be expected when looking for/or open to a new relationship than when monogamously mated. As expected, we found that gay men presented higher scores for body dissatisfaction and drive for thinness if they were looking for/or open to new romantic or sexual partners. This result would indicate a greater attention/concern to the evaluation of their own physical appearance when looking for partner. As Siever [27] suggested, gay men pursuing a partner suffer increased pressure to be physically attractive, and those who feel they do not meet the high attractiveness ideals of the gay community may experience heightened body image concerns, as they feel their bodies may not be appealing enough to attract a partner. Men in relationships may be less exposed to objectifying experiences within the gay culture compared with single men actively pursuing partners and putting themselves in environments where such pursuits may occur, such as in gay clubs or on dating websites and apps [63]. As Parker and Harriger [64] pointed out, among sexual minority men, the use of dating apps was found to be an ED risk factor, which is likely due to the added pressure to adhere to a certain aesthetic to attract more potential sexual partners. Brown and Keel [65] showed that, although it made no difference to heterosexual men, bisexual and gay men who were single had an increased drive for thinness, and that being in a relationship may be a protective factor for body image concerns and disordered eating among gay men. Cella et al. [33] also found gay sexual orientation associated with greater body dissatisfaction and abnormal eating behaviors in men, especially among those who were not in a sentimental relationship. All these findings support the notion that single men may be more concerned with their appearance than those in relationships; our results also support that gay men are at higher risk when they are open to finding a new partner.

In contrast, we did not find an effect of relationship status on the symptomatology of heterosexual women. As stated previously, Siever’s [27] hypothesis does not seem to apply fully in the case of women. This result is consistent with other studies that found that the symptomatology of lesbian women was not always less than that of heterosexual women [62], and that explanatory models of ED etiology followed similar patterns in lesbian and heterosexual women, but not in heterosexual and gay men [66]. Our mediation analysis pointed suggestively in the same direction. While in men the differences in body dissatisfaction derived from sexual orientation were fully explained by their drive for thinness, in the case of women, thinness only partially explained body dissatisfaction. Thus, the thin-ideal seem to fully explain differences in body dissatisfaction between heterosexual and gay men, but not completely between heterosexual and lesbian women.

The cognitive component of body dissatisfaction has been considered to contain two categories, preoccupation with the body and self-objectification on the one hand, and internalization of the thin-ideal, on the other [43]. Objectification theory [57] posits that girls and women are acculturated to internalize an observer’s perspective as a primary view of their physical selves, and that women could respond to sexual objectification in function of sexuality, age, ethnicity, and other physical and personal attributes. Cultural objectification can be internalized as self-objectification leading to increased body monitoring and body dissatisfaction [67,68,69]. Therefore, differences between lesbian and heterosexual women may lie not only in the direction of the attraction, but in a different internalization of gender roles [70, 71]. Gender role adoption is related to body dissatisfaction and EDs [72] and femininity has been considered a more critical factor than sexual preference on ED psychopathology [73]. The comparison of women with different sexual orientations could be involving two different issues, differences in the orientation of their attraction (mediated by the interiorization of beauty ideals), and differences in the process of socialization. This would explain both the inconsistency of results found in the literature on the relationship between sexual orientation and EDs in the case of women, as well as the results of the present study.

This study has several limitations. First, given the split of the sample into groups of sex, sexual orientation, and relationship status, some of these groups presented small sample sizes and the associated tests might have low statistical power. Likewise, the absence of significant results in some groups should be taken with caution. Despite this, descriptive measures of effect size seem to point in the direction of our conclusions. Second, we use the drive for thinness measure as a measure of the degree of internalization of thin-ideal, which does not fully correspond. However, different studies show a positive relationship between the two measures [74,75,76], therefore, we consider that the conclusions derived from the results are appropriate. Finally, while aiming to evaluate risk factors, the cross-sectional nature of data collection does not allow us to follow the evolution of the symptoms or to distinguish in the mediation models the antecedent variables from their outcomes.