Mate Attraction Research Articles

Females with attractive mates gain environmental benefits that increase lifetime and multigenerational fitness

Females with attractive mates gain environmental benefits that increase lifetime and multigenerational fitness

An adapted Black Widow Optimization Algorithm for Financial Portfolio Optimization Problem with cardinalty and budget constraints

Financial Portfolio Optimization Problem (FPOP) is a cornerstone in quantitative investing and financial engineering, focusing on optimizing assets allocation to balance risk and expected return, a concept evolving since Harry Markowitz’s 1952 Mean-Variance model. This paper introduces a novel meta-heuristic approach based on the Black Widow Algorithm for Portfolio Optimization (BWAPO) to solve the FPOP. The new method addresses three versions of the portfolio optimization problems: the unconstrained version, the equality cardinality-constrained version, and the inequality cardinality-constrained version. New features are introduced for the BWAPO to adapt better to the problem, including (1) mating attraction and (2) differential evolution mutation strategy. The proposed BWAPO is evaluated against other metaheuristic approaches used in portfolio optimization from literature, and its performance demonstrates its effectiveness through comparative studies on benchmark datasets using multiple performance metrics, particularly in the unconstrained Mean-Variance portfolio optimization version. Additionally, when encountering cardinality constraint, the proposed approach yields competitive results, especially noticeable with smaller datasets. This leads to a focused examination of the outcomes arising from equality versus inequality cardinality constraints, intending to determine which constraint type is more effective in producing portfolios with higher returns. The paper also presents a comprehensive mathematical model that integrates real-world constraints such as transaction costs, transaction lots, and a dollar-denominated budget, in addition to cardinality and bounding constraints. The model assesses both equality/inequality cardinality constraint versions of the problem, revealing that the inequality constraint tends to offer a wider range of feasible solutions with increased return potential.

Interactive effects of intrasexual competitiveness, same-sex competition, and physical attractiveness on temporal discounting

Studies have shown that men discount the future and prefer immediate-but-smaller over delayed-but-larger rewards when exposed to mating opportunities (e.g., attractive opposite-sex targets) or threats (e.g., same-sex competition) whereas women's discounting in response to similar cues appears mixed, suggesting that mating-motivated discounting is primarily a male phenomenon. Importantly, this line of research has not yet examined the role of individual difference variables as well as how the attractiveness of potential mates and perceptions of competition jointly influence discounting rates. We conducted a novel test of the effect of trait intrasexual competitiveness (ISC) using dating profiles varying on target attractiveness and same-sex competition to observe their interactive effects on participants' discounting. Results showed that when targets were attractive, higher ISC was associated with steeper discounting for both men and women, and this association was stronger when competition was high rather than low. ISC still predicted discounting when targets were low in attractiveness but competition was high; high ISC did not predict discounting only in the low attractiveness and low competition condition. These findings reveal ISC as a factor that leads women to discount as much as men, and that high-ISC individuals may be more responsive to competition than to target attractiveness.

Body stiffness is a mechanical property that facilitates contact-mediated mate recognition in Caenorhabditis elegans

Physical contact is prevalent in the animal kingdom to recognize suitable mates by decoding information about sex, species, and maturity. Although chemical cues for mate recognition have been extensively studied, the role of mechanical cues remains elusive. Here, we show that C.elegans males recognize conspecific and reproductive mates through short-range cues, and that the attractiveness of potential mates depends on the sex and developmental stages of the hypodermis. We find that a particular group of cuticular collagens is required for mate attractiveness. These collagens maintain body stiffness to sustain mate attractiveness but do not affect the surface properties that evoke the initial step of mate recognition, suggesting that males utilize multiple sensory mechanisms to recognize suitable mates. Manipulations of body stiffness via physical interventions, chemical treatments, and 3D-printed bionic worms indicate that body stiffness is a mechanical property for mate recognition and increases mating efficiency. Our study thus extends the repertoire of sensory cues of mate recognition in C.elegans and provides a paradigm to study the important roles of mechanosensory cues in social behaviors.

Multilevel analysis of acoustic variation in a Scinax fuscomarginatus population (Anura, Hylidae) of Central Brazil

The vocalisations of anurans are one of their principal forms of communication and are mainly used for specific recognition involving the attraction of reproductive mates and territorial defense. In this study, we analysed the advertisement calls of 101 individuals from a population of Scinax fuscomarginatus sampled in the type locality of S. pusillus (currently under the synonymy of S. fuscomarginatus). Specifically, we investigated acoustic variation at several levels: intraindividual, interindividual, throughout the night, and across six breeding seasons by analysing temporal and spectral parameters. We identified that all parameters of the advertisement call can be used for individual recognition, with the maximum frequency having the greatest potential. We then observed that all other acoustic parameters were influenced by the predictor variables, with the exception of maximum frequency. The air temperature negatively influenced call duration, number of pulses, dominant frequency and minimum frequency; while it positively influenced pulse rate and call rate during the breeding season. Furthermore, with the exception of call duration and pulse rate, the other acoustic parameters varied significantly across the different nocturnal periods. This study provides data on the variation in S. fuscomarginatus acoustic features. Besides, we also discuss the implications of individual recognition. Studies that consider different sources of variation for the same population of a given species are uncommon, but of paramount importance for understanding the behavioural dynamics of the population. Keywords: advertisement call, behaviour, individual recognition, sexual-selection

Relax Your Fear—The role of autonomous sensory meridian response (ASMR) in green advertising

As a novel approach in green advertising, the autonomous sensory meridian response (ASMR), which induces relaxation and pleasure, is expected to relieve the excessive negativity caused by a negative environmental message. Drawing from the fear-relief theory, mating attraction strategy, and rational choice theory, this experimental study investigated the effectiveness of embedding ASMR within a negative green ad in controlling viewers' fear. It also explored the effects of ASMR on buying intention between two different perceived-difficulty eco-friendly products. The study involved 240 young adults. The findings reveal that, compared to non-ASMR exposures, interplaying negative appeal with ASMR could significantly decrease young adults' fear. Young male adults experienced lower fear than females when seeing a female ASMR-tist. In contrast, male and female adults' fears were relatively equal when seeing male ASMR-tist in a negative green message. Yet, no direct and indirect effects of lower fear on green buying intention mediated by attitude toward the ad were observed. Findings are discussed in terms of theoretical and practical contributions.

Remodeling male coercion and the evolution of sexual autonomy by mate choice.

Models of sexual conflict over mating, including conflict over indirect benefits of mate choice, have generally presumed that female resistance to male coercion must involve direct confrontation, which can lead to sexually antagonistic coevolutionary arms-races. We built a quantitative model examining the largely ignored possibility that females may evolve new, additional mate preferences for new male traits that undermine male capacity to coerce. Thus, females may "remodel" the coercive capacity of the male phenotype in order to enhance their own sexual autonomy-a novel alternative mechanism by which females may avoid arms-races. We demonstrate that evolutionary "remodeling" is possible, in spite of costs to males, because females that prefer males with protective, autonomy-enhancing traits (traits correlated with lower coercion effectiveness) are likelier to gain indirect benefits of having attractive mates. Our analysis reveals new possibilities for the evolution of systems of sexual conflict over indirect benefits, showing that autonomy-enhancing male traits can act as a "public good," benefiting all females regardless of mating preferences, leading to oscillatory dynamics; and that preferences for more protective male traits will often be favored relative to preferences for less protective traits, potentially leading to an evolutionary "snowball" of expanding sexual autonomy.

Age, but not an immune challenge, triggers terminal investment in the Pacific field cricket, Teleogryllus oceanicus.

The terminal investment hypothesis proposes that, when individuals are faced with a threat to survival, they will increase investment in current reproduction. The level of the threat necessary to elicit terminal investment (the dynamic terminal investment threshold) may vary based on other factors that also influence future reproduction. Here, we tested whether there is an interactive effect of age and an immune challenge on the dynamic terminal investment threshold in the Pacific field cricket, Teleogryllus oceanicus. We measured the courtship call, mating attractiveness, ejaculate size, and offspring production of T. oceanicus males. We found only limited support for the dynamic terminal investment threshold: there was no consistent evidence of a positive interaction between male age and immune challenge intensity. However, we found evidence for age-related terminal investment: older males produced a larger spermatophore than younger males. Older males also had a slower calling rate compared to younger males, suggesting a potential trade-off between these two pre- and post-copulatory traits. As some, but not all, reproductive traits responded plastically to cues for terminal investment, our research highlights the importance of considering a broad range of pre-and post-copulatory traits when exploring the potential for terminal investment to occur.

Size, scale, and design matter: Commentary on Lewis, Al-Shawaf, Semchenko, and Evans, (2022)

Commentary on an article by David M. G. Lewis, Laith Al-Shawaf, Ayten Yesim Semchenko, and Kortnee C. Evans (2022). Lewis et al. tested two cognitive algorithms for how individuals perceive attractiveness of potential mates under uncertainty. The authors hypothesized that male participants would overperceive attractiveness (MOAB) and that female participants would underperceive attractiveness (FUAB), based in an Error Management Theory analysis of choice outcomes. The authors concluded that a sex- and attractiveness-differentiated bias existed, such that men overperceived attractiveness when shown stimuli of unattractive women and that women underperceived attractiveness when shown stimuli of attractive men. A reanalysis of this data using continuous ratings of attractiveness rather than dichotomized ratings of attractiveness revealed a crossover interaction that is inconsistent with the hypothesized algorithms and no statistically significant effects of sex. Instead, these results are more consistent with an evolutionary optimality hypothesis based on Signal Detection Theory (Brandner et al., 2021). Additional methodological concerns are discussed.

Articulatory effects on perceptions of men’s status and attractiveness

Research on heterosexual mating has demonstrated that acoustic parameters (e.g., pitch) of men’s voices influence their attractiveness to women and appearance of status and formidability to other men. However, little is known about how men’s tendency to clearly articulate their speech influences these important social perceptions. In the current study, we used a repeated-measures design to investigate how men’s articulatory clarity or conformity influenced women’s (N = 45) evaluations of men’s attractiveness for both short- and long-term relationships, and men's (N = 46) evaluations of physical formidability and prestige. Results largely supported our hypotheses: men who enunciated phonemes more distinctly were more attractive to women for long-term relationships than short-term relationships and were perceived by other men to have higher prestige than physical dominance. These findings suggest that aspects of articulatory behavior that influence perceptions of prestige and long-term mating attractiveness may indicate an early social history characterized by high socioeconomic status, likely owing to crystallization of articulatory patterns during the critical period of language development. These articulatory patterns may also be honest signals of condition or disposition owing to the nature of complex, multicomponent traits, which deserve further empirical attention.

Endocrine modulation of primary chemosensory neurons regulates Drosophila courtship behavior.

The decision to engage in courtship depends on external cues from potential mates and internal cues related to maturation, health, and experience. Hormones allow for coordinated conveyance of such information to peripheral tissues. Here, we show Ecdysis-Triggering Hormone (ETH) is critical for courtship inhibition after completion of copulation in Drosophila melanogaster. ETH deficiency relieves post-copulation courtship inhibition (PCCI) and increases male-male courtship. ETH appears to modulate perception and attractiveness of potential mates by direct action on primary chemosensory neurons. Knockdown of ETH receptor (ETHR) expression in GR32A-expressing neurons leads to reduced ligand sensitivity and elevated male-male courtship. We find OR67D also is critical for normal levels of PCCI after mating. ETHR knockdown in OR67D-expressing neurons or GR32A-expressing neurons relieves PCCI. Finally, ETHR silencing in the corpus allatum (CA), the sole source of juvenile hormone, also relieves PCCI; treatment with the juvenile hormone analog methoprene partially restores normal post-mating behavior. We find that ETH, a stress-sensitive reproductive hormone, appears to coordinate multiple sensory modalities to guide Drosophila male courtship behaviors, especially after mating.

Extensive parental care experience of male seahorses increases their future mating attractiveness.

Extensive parental care experience of male seahorses increases their future mating attractiveness.

Seasonality in the Emission of Contact Calls in Spix's Disc-Winged Bats (Thyroptera tricolor) Suggests a Potential Role in Mate Attraction

Multiple studies show that animals exhibit consistent individual differences in behavior, but they also experience short-term changes in their behavioral responses associated with seasonal events, most notably reproduction. We compare calling rates between the breeding and non-breeding seasons, and between males and females, in Spix's disk-winged bats (Thyroptera tricolor). This species performs an exchange of inquiry and response calls in a context of social coordination and these vocalizations are used by individuals to signal roost location. Our results indicate that during the breeding season all males vocalize and also emit a greater number of response calls. In females, we found that there is no significant difference in their vocal behavior during the breeding and non-breeding seasons. Even though being vocal leads to greater energy costs and risk of predation, males were more vocal and emitted more vocalizations when females are known to be ovulating. Therefore, our results suggest that response calls may not only facilitate group cohesion, as found in previous studies, but that it may also play a role in courtship.

Blinded by the Light: Artificial Light Lowers Mate Attraction Success in Female Glow-Worms (Lampyris noctiluca L.).

Simple SummaryNocturnal light pollution is a worldwide growing problem, threatening nocturnal biodiversity. We studied the impact of streetlights on mating success of the female common glow-worm, a bioluminescent nocturnal beetle (Lampyris noctiluca L.) that uses light signals for sexual communication. We monitored individual females daily and assumed that when they stopped glowing, they had effectively mated. We found that females in dark surroundings typically stopped glowing after one night, while females in illuminated areas glowed for significantly more nights, in some cases up to 15 nights. Our study confirms previous hypotheses that females exposed to artificial light suffer from a reduced mate attraction success, which can lead to population declines. Our findings represent valuable information that can be used by policy makers and managers to conserve the iconic glow-worms.Nocturnal light pollution from anthropogenic origin is increasing worldwide and is recognised as a major threat for nocturnal biodiversity. We studied the impact of artificial light on the mate attraction success of female common glow-worms (Lampyris noctiluca L.) by daily monitoring their glowing status in the field, acting as a proxy for mating status throughout the mating season. We found that females in dark surroundings typically stopped glowing after one night, indicating that they had mated, while females in illuminated areas glowed for significantly more nights, in some cases up to 15 nights. Our study confirms previous findings and hypotheses that females exposed to artificial light suffer from a reduced mate attraction success with a negative impact on populations.

Male Chemical Signalling to Recruit Females in the Greater Short-Nosed Fruit Bat Cynopterus sphinx

Mate attraction via chemosignalling is common in group-living mammals. In the greater short-nosed fruit bats, Cynopterus sphinx, it remains unclear whether males use chemosignals to attract females. Here, we use field observations to describe patterns of male chemosignalling in this species, then use preference test in captivity to infer the function of chemosignals. We observed that males engage in chemosignalling through wing fanning after marking their leaf ‘tent' roosts with saliva. The male fanned each wing alternatively and vigorously and performed frequent tongue flicks to the wing membrane. Such behaviour is exhibited towards females that returned to the tent. Afterwards, the male embraced the female with both wings. Wing fanning and tent marking occurred more often during the mating season than the non-mating season. To infer the role of chemosignals in recruiting females, we performed two different choice tests. In the first test, we tested whether females preferred the tent containing cotton balls that were rubbed gently and repeatedly on the ventral side of the plagiopatagium of the male, versus a control tent without any conspecific odour. In the second test, we tested whether females preferred a tent that was marked by a male's saliva versus a control tent without such markings. The result of both tests indicated that females recognized the saliva and ‘scent’ from the wings of males, since females always preferred tents with male chemosignals over the controls. Our findings suggest that the recruitment of females and subsequent formation of a harem in the greater short-nosed fruit bats is influenced by male chemosignals.

Female differential allocation in response to extrapair offspring and social mate attractiveness.

Renewed debate over what benefits females might gain from producing extra‐pair offspring emphasizes the possibility that apparent differences in quality between within‐pair and extra‐pair offspring are confounded by greater maternal investment in extra‐pair offspring. Moreover, the attractiveness of a female's social mate can also influence contributions of both partners to a reproductive attempt. Here, we explore the complexities involved in parental investment decisions in response to extra‐pair offspring and mate attractiveness with a focus on the female point of view. Adult zebra finches paired and reproduced in a colony setting. A male's early‐life diet quality and his extra‐pair reproductive success were used as metrics of his mating attractiveness. Females paired with males that achieved extra‐pair success laid heavier eggs than other females and spent less time attending their nests than their mates or other females. Extra‐pair nestlings were fed more protein‐rich hen's egg than within‐pair nestlings. Females producing extra‐pair offspring had more surviving sons than females producing only within‐pair offspring. Collectively, results show that females differentially allocate resources in response to offspring extra‐pair status and their social mate's attractiveness. Females may also obtain fitness benefits through the production of extra‐pair offspring.

Short term, long term: An unexpected confound in human-mating research

Here I report that, when partnered people judge the facial attractiveness of potential mates for a short- and a long-term relationship, the order in which the two conditions are presented biases responses in a systematic manner. Women and men display symmetrical biases. Women find men less attractive as new long-term partners if they have first imagined them as one-night stands. Men find women less attractive as one-night stands if they have first imagined them as new long-term partners. On a total sample of over 3000 individuals from different studies, I show that both biases are robust and replicable in partnered people and neither is found in singles. Alas, so far no study has statistically controlled the effect of the order in which participants consider the two types of relationships. Whatever their interpretation, these biases are capable of producing spurious or inconsistent associations and mislead us when we compare studies that on the surface appear similar—most notably, direct and conceptual replications.

Beautification Is More than Mere Mate Attraction: Extending Evolutionary Perspectives on Female Appearance Enhancement

Beautification Is More than Mere Mate Attraction: Extending Evolutionary Perspectives on Female Appearance Enhancement

Does Exercise Make Me More Attractive? Exploring the Relations Between Exercise and Mate Value

Sexual selection in human evolution is well-established. Females are relatively more inclined than males to prefer mates that exhibit physical and social dominance (e.g., muscular, financially successful men); whereas males are relatively more inclined than females to seek mates displaying signs of high reproductive potential (e.g., young, attractive women). Given that physical training has the potential to improve traits related to sexual selection in both males and females, we examined if exercise habits altered assessments of mate value in a cross-sectional analysis of 265 undergraduate students. Participants completed a demographic questionnaire, an “Exercise Habits Inventory,” and a “Mate Value Inventory” for the assessment of the characteristics desired in their “ideal” mates and for self-perceptions of intrinsic mate value. Consistent with prior research, females preferred mates who were independent and generous, and both males and females preferred physically attractive mates. Females, independent of exercise frequency, were more selective than males as evidenced by a desire for “ideal” partners with a significantly higher mate value. Moreover, more frequent exercisers, independent of sex, had significantly higher self-perceived mate value than less frequent exercisers. Finally, a pattern consistent with theories of assortative mating was demonstrated via a significant positive relation between self-perceptions and the mate value of “ideal” partners.

Mate attraction, chemical defense, and competition avoidance in the parasitoid wasp Leptopilina pacifica

A major hypothesis for the evolution of chemical signals is that pheromones arise from non-communicative precursor compounds. However, data supporting this hypothesis are rare, primarily because the original functions of the antecedent compounds often have been lost. A notable exception, however, is the parasitoid wasp species Leptopilina heterotoma, whose compound (−)-iridomyrmecin is used as a defensive secretion, a cue for females to avoid competition with con- and hetero-specific females, and as the primary component of the females’ sex pheromone. To better understand the evolution of sex pheromones from defensive compounds, we examined the chemical ecology of L. pacifica, the sister species of L. heterotoma. Here, we show that L. pacifica also produces a defensive secretion containing a species-specific mixture of mostly iridoid compounds. However, the composition of the secretion is more complex than in L. heterotoma, and iridomyrmecin is only a minor component. Moreover, in contrast to L. heterotoma, conspecific female competitors were not avoided by female subjects, and a role of the iridoids in the female sex pheromone of L. pacifica can be excluded, as only the females’ cuticular hydrocarbons (CHCs) resulted in the elicitation of courtship by males. Although closely related, the two sister species show substantial differences in the use of the defensive secretion for communicative purposes. Variation in pheromone usage in this genus still presents a conundrum, highlighting the need for additional studies to understand the selective forces shaping the evolution of pheromone composition.