Male Sexual Orientation and Avuncularity in Canada: Implications for the Kin Selection Hypothesis

2011 ◽  
Vol 11 (3-4) ◽  
pp. 339-352 ◽  
Author(s):  
Deanna L. Forrester ◽  
Doug P. VanderLaan ◽  
Paul L. Vasey ◽  
Jessica L. Parker
Keyword(s):  
Kin Selection ◽  
Sexual Attraction ◽  
Altruistic Behavior ◽  
Adult Males ◽  
Social Tolerance ◽  
Fitness Costs ◽  
Future Directions ◽  
Selection Hypothesis ◽  
Indirect Fitness ◽  
Male Sexual Orientation

AbstractAndrophilia refers to sexual attraction and arousal to adult males, whereas gynephilia refers to sexual attraction and arousal to adult females. The Kin Selection Hypothesis (KSH) posits that genes for male androphilia can persist if androphilic males offset the fitness costs of not reproducing directly by enhancing indirect fitness. In theory, by directing altruistic behavior toward kin, androphilic males can increase the reproduction of kin, thereby enhancing indirect fitness. Evidence supporting the KSH has been documented in Samoa. Samoan transgendered, androphilic males, known locally as fa’afafine, are socially accepted by the majority of Samoans. In contrast, no supportive evidence has been garnered from other cultures (i.e., USA, UK, Japan) that are characterized by less social tolerance toward male androphiles. Tests of the KSH in Canada might be more likely to yield findings consistent with Samoa because Canadian social and political attitudes toward male androphiles are markedly more tolerant and accepting. Here, we compared the willingness of Canadian androphilic men, gynephilic men, and androphilic women to invest in nieces and nephews as well as in non-kin children. Consistent with the KSH and findings from Samoa, androphilic men exhibited a significantly greater cognitive dissociation between altruistic tendencies directed toward kin versus non-kin children relative to gynephilic men and androphilic women. The present study, therefore, provides some tentative support for the KSH from a culture other than Samoa. Findings and future directions for research are considered within the context of the existing cross-cultural literature.

Does Geographic Proximity Influence The Expression of Avuncular Tendencies in Canadian Androphilic Males?

2014 ◽  
Vol 14 (1-2) ◽  
pp. 41-63 ◽  
Author(s):  
Miranda L. Abild ◽  
Doug P. VanderLaan ◽  
Paul L. Vasey
Keyword(s):  
Sexual Attraction ◽  
Inclusive Fitness ◽  
Cross Cultural ◽  
Altruistic Behavior ◽  
Adult Males ◽  
Geographic Proximity ◽  
Fitness Costs ◽  
Evolutionary Time ◽  
Cross Cultural Differences ◽  
Willingness To Engage

AbstractAndrophilia refers to sexual attraction and arousal to adult males, whereas gynephilia refers to sexual attraction and arousal to adult females. The Kin Selection Hypothesis posits that male androphilia may persevere over evolutionary time if the fitness costs of not reproducing directly are offset by increasing one’s inclusive fitness. Theoretically, this could be accomplished by allocating altruism toward close kin, thereby increasing the ability of those kin to reproduce. Evidence for this hypothesis has been garnered from research conducted in Samoa; however, no support has been garnered from research conducted in other, more industrialized cultures (i.e., Canada,usa,uk, Japan). It has been suggested that geographic disconnect from kin might mitigate the potential for androphilic males to exhibit elevated kin-directed altruism in more industrialized cultures. We examined whether Canadian androphilic males expressed elevated willingness to engage in altruistic behavior towards nieces and nephews, compared to gynephilic males and androphilic females, when the activities in question could be executed from a distance. Contrary to our prediction, when comparing groups for willingness to engage in altruistic behavior towards nieces and nephews that could be performed from a distance, we did not find that Canadian androphilic males exhibited significantly higher avuncular (uncle-like) tendencies. Other possible reasons for cross-cultural differences in avuncular tendencies by androphilic males are discussed.

scholarly journals An infanticide attempt by a free-roaming feral stallion ( Equus caballus )

2008 ◽  
Vol 5 (1) ◽  
pp. 23-25 ◽  
Author(s):  
Meeghan E Gray
Keyword(s):  
Sexual Selection ◽  
Genetic Analysis ◽  
Equus Caballus ◽  
Adult Males ◽  
Free Living ◽  
Feral Horses ◽  
Selection Hypothesis ◽  
Sexual Selection Hypothesis ◽  
In Captivity

Infanticide by adult males occurs in a variety of species. While infanticidal attacks have been documented in several equid species in captivity, it has never been witnessed in free-roaming feral horses. I report an infanticide attempt by a free-living feral stallion on a recently born female foal. The stallion picked up the foal by the shoulders, tossed it around twice and bit in on the neck several times. The dam of the foal charged the stallion and successfully protected her foal from additional attacks. The foal survived the attack and later weaned successfully. The stallion recently took over the band and was excluded as the sire through genetic analysis. While this type of attack is rare, this case lends support to the sexual selection hypothesis and further demonstrates that equids have evolved with the risk of infanticide. Furthermore, it shows that maternal protectiveness can be successful against attacks by infanticidal males.

scholarly journals Males harm females less when competing with familiar relatives

2017 ◽  
Vol 284 (1867) ◽  
pp. 20171984 ◽  
Author(s):  
Samuel J. Lymbery ◽  
Leigh W. Simmons
Keyword(s):  
Egg Production ◽  
Callosobruchus Maculatus ◽  
Genetic Relatedness ◽  
Inclusive Fitness ◽  
Fitness Costs ◽  
Offspring Production ◽  
Social Familiarity ◽  
Indirect Fitness ◽  
Opposite Sex ◽  
Female Lifespan

Sexual conflict occurs when reproductive partners have different fitness optima, and can lead to the evolution of traits in one sex that inflict fitness costs on the opposite sex. Recently, it has been proposed that antagonism by males towards females should be reduced when they compete with relatives, because reducing the future productivity of a female would result in an indirect fitness cost for a harmful male. We tested this prediction in the seed beetle Callosobruchus maculatus , the males of which harm females with genital spines and pre-copulatory harassment. We compared lifespan, lifetime egg production and lifetime offspring production among females housed with groups of males that varied in their familiarity and relatedness. Females produced significantly more eggs and offspring when grouped with males who were both related and familiar to each other. There was no effect of male relatedness or familiarity on female lifespan. Our results suggest that males plastically adjust their harmfulness towards females in response to changes in inclusive fitness payoffs, and that in this species both genetic relatedness and social familiarity mediate this effect.

Socially tolerant relationships among wild male moor macaques (Macaca maura)

Behaviour ◽  
2014 ◽  
Vol 151 (7) ◽  
pp. 1021-1044 ◽  
Author(s):  
Erin P. Riley ◽  
Cristina Sagnotti ◽  
Monica Carosi ◽  
Ngakan Putu Oka
Keyword(s):  
Social Relationships ◽  
Dominance Rank ◽  
Moderate Intensity ◽  
High Symmetry ◽  
Adult Males ◽  
Social Tolerance ◽  
Affiliative Behavior ◽  
Moor Macaques ◽  
Contact Hours ◽  
Social Style

Researchers are increasingly documenting the existence of social tolerance and affiliative behavior among primate males, including in male-dispersing species. We investigated the nature of male social relationships in a relatively understudied macaque species, the moor macaque (Macaca maura), in order to expand our knowledge of male social relationships in male dispersing primates. The classification of social styles for primates rests largely on data about female social relationships. Therefore, by providing data on male–male relationships, we also contribute to our understanding of social style variation within the genus Macaca. Observations were conducted on a wild yet well-habituated group in Bantimurung-Bulusaraung National Park in South Sulawesi, Indonesia. We collected focal animal and ad libitum data on four adult males, recording social behavior during 209 contact hours over two field seasons in 2010 and 2011. The adult male moor macaques in this study did not interact frequently. Interactions that did occur more frequently involved affiliation rather than aggression, with greetings being the most common form of interaction. Greetings occurred in a predominately neutral context and were more common between specific males with uncertain or ambiguous dominance relationships and low-quality relationships, but the initiation of greetings was not linked to dominance rank. These results suggest that greetings enable males to communicate information about their willingness to invest in the relationship, representing one way for adult males to ease social tension and build social bonds. To expand our understanding of social style variation in Macaca, we compared our data to those published for other macaque taxa. In the present study, the observed pattern of aggression (i.e., low rate, low to moderate intensity and high symmetry) was consistent with the species’ social style classification as highly tolerant. The relatively low grooming rate and low percentage of counteraggression, however, were more consistent with the social style of less tolerant taxa. Further research is needed to determine what factors explain this pattern of social tolerance among male moor macaques.

Kin selection in Columbian ground squirrels: direct and indirect fitness benefits

2011 ◽  
Vol 21 (3) ◽  
pp. 524-531 ◽  
Author(s):  
F. STEPHEN DOBSON ◽  
VINCENT A. VIBLANC ◽  
COLINE M. ARNAUD ◽  
JAN O. MURIE
Keyword(s):  
Kin Selection ◽  
Ground Squirrels ◽  
Indirect Fitness ◽  
Fitness Benefits ◽  
Columbian Ground Squirrels

scholarly journals Looking Like a Million Dollars: Does Attractiveness Priming Increase Altruistic Behavior in Experimental Games?

2021 ◽  
Vol 12 ◽  
Author(s):  
Julie Novakova ◽  
Kamila Machová ◽  
Katerina Sýkorová ◽  
Vojtěch Zíka ◽  
Jaroslav Flegr
Keyword(s):  
Kin Selection ◽  
Evolutionary Biology ◽  
Behavioral Science ◽  
Romantic Partners ◽  
Self Report ◽  
Altruistic Behavior ◽  
Costly Signaling ◽  
Ultimatum Games ◽  
Number Of Sexual Partners ◽  
Experimental Games

The emergence of altruistic behavior constitutes one of the most widely studied problems in evolutionary biology and behavioral science. Multiple explanations have been proposed, most importantly including kin selection, reciprocity, and costly signaling in sexual selection. In order to test the latter, this study investigated whether people behave more altruistically when primed by photographs of attractive faces and whether more or less altruistic people differ in the number of sexual and romantic partners. Participants in the general population (N = 158, 84 F, 74 M) first rated the attractiveness of photographs of 20 faces of the opposite (sexually preferred) sex and then played the Dictator and Ultimatum Games (DG and UG). The photograph rating acted as priming; half the participants received photographs of people rated as more attractive than average in an earlier study, and the other half received photographs previously rated as less attractive. The attractiveness-primed participants, especially men, were expected to behave more altruistically—signaling that they are desirable, resource-possessing partners. We also expected altruists to self-report more sexual and romantic partners. The observed difference between altruistic behaviors in the attractiveness- and unattractiveness-primed groups occurred in UG offers, however, in the opposite than expected direction in women. The number of sexual partners was positively correlated to minimum acceptable offers (MAOs) in the UG, in line with expectations based on the theory of costly signaling.

scholarly journals Sexual selection and the evolution of altruism: males are more altruistic and cooperative towards attractive females

2016 ◽  
Vol 7 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Manpal Singh Bhogal ◽  
Niall Galbraith ◽  
Ken Manktelow
Keyword(s):  
Game Theory ◽  
Sexual Selection ◽  
Kin Selection ◽  
Self Report ◽  
Economic Games ◽  
Selection Hypothesis ◽  
Contemporary Research ◽  
Sexual Selection Hypothesis ◽  
Game Theoretic

Explaining altruism through an evolutionary lens has been a challenge for evolutionary theorists. Where altruism towards kin is well understood through kin selection, altruism towards non-kin is an evolutionary puzzle. Contemporary research has found that, through a game-theoretic framework, sexual selection could be an explanation for the evolution of altruism. Research suggests that males are more altruistic towards females they are interested in engaging with, sexually or romantically when distributing stakes in economic games. This study, adopting a between-groups design, tested the sexual selection explanation for altruism by asking participants to self-report altruistic and cooperative intention when reading moral scenarios accompanied by attractive or unattractive images. We find that participants, particularly males, report being more altruistic and cooperative when viewing an attractive image of a female. This study replicates the sexual selection hypothesis in explaining altruism through an alternative experimental framework to game theory.

scholarly journals The evolution of infanticide by females in mammals

2018 ◽  
Author(s):  
Dieter Lukas ◽  
Elise Huchard
Keyword(s):  
Reproductive Output ◽  
Mammalian Species ◽  
Female Aggression ◽  
Fitness Costs ◽  
Qualitative Synthesis ◽  
Female Infanticide ◽  
Taxonomic Distribution ◽  
Competitive Behaviour ◽  
Indirect Fitness ◽  
Critical Resources

AbstractIn most mammalian species, females regularly interact with kin, and it may thus be difficult to understand the evolution of some aggressive and harmful competitive behaviour among females, such as infanticide. Here, we investigate the evolutionary determinants of infanticide by females by combining a quantitative analysis of the taxonomic distribution of infanticide with a qualitative synthesis of the circumstances of infanticidal attacks in published reports. Our results show that female infanticide is widespread across mammals and varies in relation to social organization and life-history, being more frequent where females breed in groups and have intense bouts of high reproductive output. Specifically, female infanticide occurs where the proximity of conspecific offspring directly threatens the killer’s reproductive success by limiting access to critical resources for her dependent progeny, including food, shelters, care or a social position. In contrast, infanticide is not immediately modulated by the degree of kinship among females, and females occasionally sacrifice closely related juveniles. Our findings suggest that the potential direct fitness rewards of gaining access to reproductive resources have a stronger influence on the expression of female aggression than the indirect fitness costs of competing against kin.

Development, Standardization, and Experimental Application of a Human Performance Measurement System

1979 ◽  
Vol 23 (1) ◽  
pp. 546-546
Author(s):  
Dorothy E. Fletcher
Keyword(s):  
Performance Measurement ◽  
Measurement System ◽  
Human Performance ◽  
Sea Water ◽  
Computer Control ◽  
Performance Measurement System ◽  
Adult Males ◽  
Future Directions ◽  
Experimental Use ◽  
Normal Laboratory

A human performance measurement system is described in terms of apparatus components, mini- and micro-computer control of test administration and data analysis, and experimental applications. At present, computer programs have been tested to administer and score twenty five performance tests, which were selected, modified, and/or developed to assess relatively independent perceptual, memory, cognitive, and psychomotor abilities. In the first experimental use of the system, six subjects were administered different subgroups of from three to five tests throughout one or both of two hyperbaric exposures while breathing normoxic helium. The first dive was to 1200 fsw (equivalent feet of sea water); the second, to 1600 fsw. In the second experiment, test standardization is proceeding with a group of young, adult males and with a larger and more heterogeneous adult group. Under normal laboratory conditions, equivalent forms of these tests are being compared with marker tests. The third experiment evaluates the effects upon an individual subject's pattern of abilities of changes in composition of inspired gases at sea level, in this case, changes in concentrations of N2O and O2. Future directions of development and application of this system are discussed.

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