What Drives Sex Toy Popularity? A Morphological Examination of Vaginally-Insertable Products Sold by the World's Largest Sexual Wellness Company.

There is limited research into the morphology of sex toys, and specifically into (the often phallic-shaped) vibrators and dildos and what they may represent in terms of user preferences for male genital morphology. This study provides insight into consumer preference around vaginally insertable sex toys, their features, and what contributes to their popularity. Using a data set compiling information from the world's largest online sexual wellness retailer Lovehoney, we examined the dimensions, price, and morphological features of 265 sex toys designed for vaginal insertion to determine what contributes to item popularity. Using regression models, we found that realistic features did not predict item popularity, whereas price (p < .001) and circumference (p = .01) significantly predicted the overall popularity of a toy. It appears that consumers show a preference for insertable sex toys that are not direct replicas of the male penis, which suggests they are not seeking a realistic partner substitute. Further, we found that the length of the toy did not significantly predict popularity which is consistent with other work showing that women do not place considerable emphasis on large phallus size. Our results can contribute to future product design and marketing, as well as reveal preferences toward particular characteristics of the phallus (whether real or toy).

Sexual dimorphism of pelvic scarring: A new method of adult biological sex estimation.

Estimating biological sex is a crucial aspect of forensic anthropology, and is pivotal in forensic investigations. Presently, the most frequently adopted osteological sex estimation methods focus on the anterior pelvis, which is easily susceptible to postmortem damage, revealing a need for additional accurate methods. This study introduces a novel method for estimating adult sex through metric pelvic scar analysis, using a known skeletal sample (169 females; 51 males). Relationships between sex and scar dimensions were subjected to Kendall's tau-B testing, and the strongest associated measurements were further analyzed using binary logistic regression to determine their predictive capacity. The final estimation method was tested on an additional known-sex sample of 43 males and 43 females from the Spitalfields skeletal collection. All associations between biological sex and scar measurements were significant, with the preauricular sulcus and newly defined inferior interosseous cavity presenting the strongest relationships (τb 0.223-0.504). Individual regression models using the approximate volume of each feature predicted sex with over 80% accuracy, but when combined in a single regression model, the accuracy increased to an impressive 97.1%. When then applied to the validation sample, the final estimation model achieved an accuracy of 90.7%. These results highlight the high estimation accuracy achieved by simultaneously utilizing the approximate volume of the sulcus and the inferior cavity. This is not only highly accurate but also utilizes the sturdier posterior pelvis, making it a promising tool for forensic investigations and the wider field of osteology.

The use and misuse of evolutionary psychology in online manosphere communities: The case of female mating strategies.

While early evolutionary accounts of female sexuality insisted on coyness and monogamous tendencies, evidence from the field of primatology started challenging those assumptions in the 1970s. Decades later, there exist many competing and overlapping hypotheses stressing the potential fitness benefits of female short-term and extra-pair mating. Female mammals are now seen as enacting varied and flexible reproductive strategies. This is both a victory for science, with a better fit between theory and reality, and for feminism, with the downfall of narrow stereotypes about female sexuality. However, evolutionary hypotheses on female mating strategies are routinely invoked among the antifeminist online communities collectively known as 'the manosphere'. Based on extensive qualitative analysis of manosphere discourse, this study shows how these hypotheses are sometimes interpreted in misogynistic online spaces. Indeed, evolutionary scholars might be surprised to see sexist worldviews reinforced by the 'dual mating strategy' and 'sexy son' hypotheses, or by the latest research on the ovulatory cycle. The manosphere has its own version of evolutionary psychology, mingling cutting-edge scientific theories and hypotheses with personal narratives, sexual double standards and misogynistic beliefs. After analysing this phenomenon, this article suggests ways to mitigate it.

Food taboos during pregnancy: meta-analysis on cross cultural differences suggests specific, diet-related pressures on childbirth among agriculturalists.

Pregnancy is the most delicate stage of human life history as well as a common target of food taboos across cultures. Despite puzzling evidence that many pregnant women across the world reduce their intake of nutritious foods to accomplish cultural norms, no study has provided statistical analysis of cross-cultural variation in food taboos during pregnancy. Moreover, antenatal practices among forager and agriculturalists have never been compared, despite subsistence mode being known to affect staple foods and lifestyle directly. This gap hinders to us from understanding the overall threats attributed to pregnancy, and their perceived nutritional causes around the world. The present study constitutes the first cross-cultural meta-analysis on food taboos during pregnancy. We examined thirty-two articles on dietary antenatal restrictions among agricultural and non-agricultural societies, in order to: (i) identify cross-culturally targeted animal, plant and miscellaneous foods; (ii) define major clusters of taboo focus; (iii) test the hypothesis that food types and clusters of focus distribute differently between agricultural and non-agricultural taboos; and (iv) test the hypothesis that food types distribute differently across the clusters of taboo focus. All data were analysed in SPSS and RStudio using chi-squared tests and Fisher's exact tests. We detected a gradient in taboo focus that ranged from no direct physiological interest to the fear of varied physiological complications to a very specific concern over increased birth weight and difficult delivery. Non-agricultural taboos were more likely to target non-domesticated animal foods and to be justified by concerns not directly linked to the physiological sphere, whereas agricultural taboos tended to targed more cultivated and processed products and showed a stronger association with concerns over increased birth weight. Despite some methodological discrepancies in the existing literature on food taboos during pregnancy, our results illustrate that such cultural traits are useful for detecting perception of biological pressures on reproduction across cultures. Indeed, the widespread concern over birth weight and carbohydrate rich foods overlaps with clinical evidence that obstructed labor is a major threat to maternal life in Africa, Asia and Eurasia. Furthermore, asymmetry in the frequency of such concern across subsistence modes aligns with the evolutionary perspective that agriculture may have exacerbated delivery complications. This study highlights the need for the improved understanding of dietary behaviors during pregnancy across the world, addressing the role of obstructed labor as a key point of convergence between clinical, evolutionary and cultural issues in human behavior.

Male infants and birth complications are associated with increased incidence of postnatal depression.

RATIONALE: A growing body of literature links both depressive symptoms generally, and those specifically in the postnatal period, with an inflammatory immune response. Evolutionary medical approaches, such as the Pathogen Host Defence Theory of Depression (PATHOS-D), have likened depression to sickness behaviour in other mammals, and propose that the characteristics associated with depression are protective when an individual is experiencing pathogenic threat. Many known risk factors for depressive symptoms are associated with activation of inflammatory pathways, opening up the potential for identifying novel risk factors based on their inflammation causing effects. OBJECTIVE: Both the gestation of male foetuses and the experience of birth complications have documented associations with increased inflammation, yet their relationships with postnatal depression (PND) are currently unclear. METHOD: Here we use the complete reproductive histories of 296 women from contemporary, low fertility populations gathered by retrospective survey to assess whether the odds of PND increased when mothers gave birth to male infants or experienced birth complications, using generalised estimating equation models controlling for individual effects of the mother and other known PND risk factors. RESULTS: We found the odds of PND increased by 71-79% when male infants were born compared to female infants. The occurrence of birth complications increased the odds of PND by 174% compared to having no complications. Testing for interaction effects found that, while always at increased risk of PND, women with a tendency towards symptoms of depression, anxiety, and stress at other points in the life course had reduced odds of PND when experiencing birth complications, suggesting such women may elicit greater support. CONCLUSIONS: These results highlight two novel PND risk factors, male infants and birth complications, which can be easily assessed by health professionals.

Postnatal depression is associated with detrimental life-long and multi-generational impacts on relationship quality.

Postnatal depression (PND) is known to be associated with a range of detrimental child and adolescent outcomes, resulting from its disruptive impact on mother-child relationship quality. However, until now little has been known about the impact of PND on the longer-term relationships between mothers and their children, and any intergenerational effects this may have. Mother-child relationship quality is of interest from an evolutionary perspective as it plays a role in the accrual of offspring embodied capital, thus affecting offspring quality and offspring's capacity to subsequently invest in their own children. Relationships with offspring also mediate grandparent-grandchild relations; if PND negatively affects long-term mother-offspring relationship quality, it is also likely to negatively affect grandmaternal investment via reduced grandmother-grandchild relationship quality. Here, we use responses to a retrospective questionnaire study of postmenopausal women, largely from the UK and US, to assess the impact of PND occurring in generation 1 on mother-child relationship quality across the life course of the child (generation 2) with whom it was associated, and also on the relationship quality with grandchildren (generation 3) from that child. Average mother-child relationship quality was lower when the child's birth was associated with PND. Multi-level regression modelling found that mother-child relationship quality decreased as PND symptom severity increased after controlling for individual effects and a variety of other factors known to influence relationship quality (individual mothers n = 296, mother-child dyads n = 646). Additionally, intergenerational relationships appear to be affected, with PND negatively associated with grandmother-grandchild relations (individual grandmothers n = 125, relations with grandchildren from n = 197 grandmother-parent dyads). That PND has long-term detrimental consequences for mother-child relationships, well beyond adolescence, highlights the need for investment in strategies to prevent PND and its cascade of negative multigenerational effects.

Construction of CRISPR Libraries for Functional Screening.

Identification of gene function has been aided by the ability to generate targeted gene knockouts or transcriptional repression using the CRISPR/CAS9 system. Using pooled libraries of guide RNA expression vectors that direct CAS9 to a specific genomic site allows identification of genes that are either enriched or depleted in response to a selection scheme, thus linking the affected gene to the chosen phenotype. The quality of the data generated by the screening is dependent on the quality of the guide RNA delivery library with regards to error rates and especially evenness of distribution of the guides. Here, we describe a method for constructing complex plasmid libraries based on pooled designed oligomers with high representation and tight distributions. The procedure allows construction of plasmid libraries of >60,000 members with a 95th/5th percentile ratio of less than 3.5.

A Rapid Combinatorial Approach to Assembling Synthetic Prokaryotic and Eukaryotic Protein Expression Vectors.

Vector construction and gene cloning are ubiquitous techniques essential to all fields of biological and medical research. They are the first steps in many endeavors leading to expressing proteins to understand gene function and regulation. However, they can often be rate-limiting, particularly in multi-gene studies, due to the time and effort required to assemble gene constructs and to identify the optimal constructs for protein expression.The SureVector system was developed to address this by enabling the rapid and reliable assembly of multiple DNA modules into a recombinant plasmid containing a gene-of-interest (GOI). It harnesses the power of synthetic biology to combine DNA modules from standard parts into a customized vector that expresses proteins in bacterial, mammalian, or yeast cells. The key advantages of the innovative SureVector system include rapid custom vector generation, enhanced flexibility to assemble new vectors quickly as experimental requirements change, and the reliable and precise assembly of fully interchangeable standard DNA modules that retain their functionality. The SureVector system is the only next-generation plasmid assembly technology to guarantee assembly of multiple functional DNA modules.

Postnatal depression and reproductive success in modern, low-fertility contexts.

BACKGROUND AND OBJECTIVES: Postnatal depression (PND) presents a puzzling phenomenon to evolutionary anthropologists as it is highly prevalent and yet detrimental to child development and maternal health. Adaptive explanations have been proposed, but have not been tested with data that directly link PND to female fertility. METHODOLOGY: A survey was designed to gather complete reproductive histories and retrospective measures of PND to measure the effects of PND on fitness. Respondents were born between 1930 and 1967, with the majority based in the UK during their childrearing years. The hypothesis that PND is detrimental to fitness is assessed using Mann-Whitney U tests on completed fertility. Binary logistic regression modelling is used to test the hypothesis that PND reduces the likelihood of parity progression. RESULTS: Women experiencing PND at their first or second birth have lower completed fertility, with PND at the first birth leading to lowered fertility. Logistic regression analyses show that this is the result of reductions in the likelihood of parity progression to a third birth when PND is experienced at the first birth or when repeat bouts occur. CONCLUSIONS AND IMPLICATIONS: Our results call into question adaptationist arguments, contribute to the growing understanding of the importance of emotional wellbeing to fertility decision making, and given the economic consequences of markedly below replacement fertility, highlight a potential new source of financial incentive to invest in screening and preventative measures to ensure good maternal mental health.

Subjective life expectancy predicts offspring sex in a contemporary British population.

There is evidence that women who are in poor physical condition or who reside in deprived environments are more likely to give birth to daughters than to sons. Under deprived environmental conditions, or when in poor physical health, it has been hypothesized that parents should take into account the available resources and manipulate the sex of any children born. Using subjective life expectancy (SLE) as a measure of how an individual views their future health and environment, I demonstrate that there is an association between the sex of the first child and SLE in a sample of mothers from a contemporary British population (Gloucestershire, UK). SLE was a significant predictor of offspring sex: women who believed that they had longer to live were more likely to have had a male birth than women who thought they would die earlier. Detection of such a bias among the children of British mothers may provide evidence that the sex ratio under relatively affluent Western conditions can still be influenced by adverse environmental or poor maternal condition.

Red is not a proxy signal for female genitalia in humans.

Red is a colour that induces physiological and psychological effects in humans, affecting competitive and sporting success, signalling and enhancing male social dominance. The colour is also associated with increased sexual attractiveness, such that women associated with red objects or contexts are regarded as more desirable. It has been proposed that human males have a biological predisposition towards the colour red such that it is 'sexually salient'. This hypothesis argues that women use the colour red to announce impending ovulation and sexual proceptivity, with this functioning as a proxy signal for genital colour, and that men show increased attraction in consequence. In the first test of this hypothesis, we show that contrary to the hypothesis, heterosexual men did not prefer redder female genitalia and, by extension, that red is not a proxy signal for genital colour. We found a relative preference for pinker genital images with redder genitalia rated significantly less sexually attractive. This effect was independent of raters' prior sexual experience and variation in female genital morphology. Our results refute the hypothesis that men's attraction to red is linked to an implied relationship to genital colour and women's signalling of fertility and sexual proceptivity.

Perceived environmental risk as a predictor of teenage motherhood in a British population.

Previous studies have shown that strong relationships exist between deprived environments and teenage motherhood. However, such studies have predominantly identified deprivation using neighbourhood-wide measures of socio-economic status. Few studies of teenage parenthood have examined how individuals perceive their environment and the importance of this perception on reproductive behaviour and timing. Using data collected from a sample of women living the county of Gloucestershire, UK, this paper explores the predictive value of two methods of assessing the environment: (1) the structural component-deprivation at the neighbourhood level and (2) the individual's subjective experience of her pre-pregnancy environment, when examining how the wider environmental context can influence the decision of becoming a teenage mother. The results indicate that a woman's perception of her neighbourhood of residence at the time she conceived, her perceived environmental risk, may be a more discriminating predictor of teenage motherhood than deprivation measured by ward economic and deprivation indicators.