117 Table 24: Summary bootstrapped (B=10000) 𝑾 for gender visual attractiveness ranking by pairwise comparisons of sexual orientation. 120 Table 28: Summary of bootstrap (B=10000) 𝑾 for odor attractiveness ranking for sex by pairwise comparisons of sexual orientation.
Introduction
According to Saxton et al. 2008), pheromones are chemical signals released by animals that are said to produce olfactory responses in other conspecifics (animals of the same species). This research will replicate previous studies conducted using t-shirts to examine attraction to sexually dimorphic traits and subsequent mating choice in different SOs, but due to the small sample size, any interpretation from the results must be discerned with caution (Gobrogge, et al. , 2007; Jankowiak, Hill, & Donovan, 1992; Rahman & Hull, 2005).
Review of Literature
Introduction: What is Sexual Selection?
Good childbearing hips and mutation-free inherited genes are not expected to influence an individual's choice of mate when reproduction is not the goal (Iemmola & Camperio Ciani, 2009; Roughgarden, 2008), and therefore the traditional sexual selection theories are often considered to be " heterosexist” in their assumptions (Roughgarden, 2008).
Evolutionary Theories on Sexual Selection
- Dimorphism
- Sexual Strategies Theory
- Pheromones
- Putative Pheromones as a Beckoning Quality
T is an immunosuppressant and thus survival and health despite indications of high T indicates immune system efficiency (Penton-Voak, et al., 1999). According to Havlicek et al. 2010) the apocrine gland is responsible for the secretion of pheromones.
The T-shirt studies
- Aim
- T-shirt Study Methodology
- Results of Previous T-shirt Studies
For the study conducted by Thornhill and Gangestad (1995), participants were also required to rate each of the t-shirts out of ten and as before on the criteria of intensity, pleasantness and sexiness. However, this study differed in that it only asked men to rate 18 pairs of t-shirts worn by women (one t-shirt worn during the follicular phase and the other in the luteal phase) and participants were not informed about the ovulatory status of any of the t-shirt wearers.
Sexual Orientation
- Androgyny: Understanding Gender Roles
- The Personal Attributes Questionnaire (PAQ)
According to Berzins, et al. 1978) measures of androgyny were superior to traditional measures of masculinity and femininity in predicting interpersonal interactions and behavior. Finlay and Schmeltema (1991) state that their results confirm previous findings in the same research area.
The Basis for Differences in Sexual Orientation
- Biological Explanations
- Social Explanations
- Partner Preferences for Homosexual Individuals
- Putative Pheromone Attraction in Homosexual Individuals
According to Bailey et al. (1994), HeW care more about the social status of potential partners than any of the other three groups. Savic et al. (2005) investigated the effects of AND and EST chemicals on the brains of individuals with different SOs.
Methodology
Aims 54
- Objective 1
- Objective 2
Research Design
In terms of design coherence, the research questions of this study require a quantitative design because quantifiable differences in responses are needed rather than subjective experience. Moreover, this research is based on the theory of evolution, which defends the idea of objective truth, a positivist ontology. had been used. This study used a questionnaire in which participants were asked to rank a series of stimuli in order. However, all participants were asked to rank all stimuli, introducing threats to internal validity normally associated with a within-subjects design, such as order or test effects and instrumentation ( Gravetter & Forzano, 2009 ).
A discussion of the effect of order effects and how it was mitigated can be found in section 3.6. This was particularly important in this study, as the t-shirts were very susceptible to odor decay and contamination with time and use.
Sampling, Recruitment and Data Collection
- The Stimuli
- The Judges
Each of the t-shirts was sealed with a bar of unscented soap in a large resealable Ziploc bag. After the second initial phase of data collection, worsening of SS had occurred after the scent on the t-shirts was changed (Gravetter & Forzano, 2009). Participants were once again explained the purpose and rules of the study and verbally agreed to participate again.
Due to the limited time for data collection unavoidable due to the instrumentation of the odor on the t-shirts, only a small sample was obtained. Place the code on the back of the photos in the block corresponding to the attractiveness ranking.
Ethical Considerations
- Informed Consent and Respect for Autonomy
- Non-Maleficence
- Beneficence
- Justice
The questionnaires were also locked in a cupboard to ensure participant confidentiality. However, participants were asked if they would like to receive information about the results of the research and were asked to provide contact details if so. Trial participants were also provided with the contact details of the researcher and the supervising researcher should they have any questions, complaints or comments.
However, participants were asked whether they would like to be informed of anonymized study results as a form of indirect benefit. All participants were well informed about the aims and requirements of the study and participated voluntarily and without coercion.
Validity and Reliability
- The Questionnaire
- Threats to Internal and External Validity
In this study, a number of possible extraneous variables were considered as potential threats to the internal validity of the research. First, participant demographics, both for stimuli and judges, were considered potentially confounding. The race of the stimulus participants was also considered a threat to internal validity as previously mentioned, as it is inextricably linked to culture and subsequent diet, which would affect BO (van Beek, 1992).
Therefore, all stimulus items used in the study were produced by participants who were reported to be heterosexual. According to Campbell (1957), the threat that instrument decay can have on the internal validity of a study occurs when a change in the measuring instrument affects the outcome of the dependent variable.
Data Analysis
- Friedman’s Two-way Analysis of Variance by Ranks
- Kendall’s Coefficient of Concordance ( 𝑾 )
- Bootstrapping
- Objective 1
- Objective 2
- Additional Analyses
The test statistic of interest is then calculated for the resampled sample for each of m permutations of the resampling process (in this study, all original samples were resampled m=10000 times). In this case k=62, since each of the 31 respondents gave rankings for both measures of attractiveness and masculinity for each stimulus. However, the data were similarly detailed in the second of the Friedman's tests for the odor stimuli (t-shirts).
First, a Friedman test was used to assess whether there was any difference in ranking between SOs for each of the two measures and stimuli. After the significance test, a series of 𝑊̃ tests were performed for each of the four sex groups.
Results
Demographic and Descriptive Statistics
- Response Rate
The pie chart (Figure 12) below indicates the proportions of gender by SO groups for the total sample. As can be seen in the graph, heterosexual women make up the most of the sample with 55%, and both homosexual groups of men and women comprise 13% each of the total sample. The next demographic consideration was race, of the 31 participants who completed the questionnaire, 48.4% indicated that they were Black, 25.8% that they were Indian, and both White and Colored responses each made up 12.9% of the total sample.
The response rate for the questionnaire was calculated by dividing those questionnaires that were satisfactorily answered (N=31) by all those questionnaires that were distributed (N=52), so the response rate was 59.62%. The poor response rate may be due to the effects of the instrument in that the participants' olfactory senses were fatigued and consequently they could not sort the T-shirts properly and thus left part of the questionnaire, or perhaps they saw the procedure uncomfortable and thus chose non-response as a form of participation withdrawal.
Objective One
- Question 1
- Question 2
The lack of significance leads to failure to reject the null hypothesis that there is no significant difference between the ranking of the stimuli items and that the researcher therefore assumes attractiveness and masculinity. Kendall's coefficient of concordance was calculated for each measure of attractiveness and masculinity for each of the stimuli, for women generally in the luteal phase of their cycle and for women estimated to be in the follicular phase of their menstrual cycle. Although there was agreement on the correlation of the attractiveness and masculinity rankings combined for the US, there was no significant agreement for the same measure of the SS.
Bootstrap of the measurements for women in their luteal phase indicated that the mean 𝑊̃ for locations combining VA and VM was significant. Match the rankings of attractiveness and masculinity of the t-shirts with the rankings of the photographs.
Objective 2
- Question 3
- Question 4
- Question 5
For men, the distribution is quite skewed, with most of the distribution at the bottom of the confidence interval. The distribution of 𝜃𝑊̃ with respect to the masculinity rankings for both genders combined, shown in Figure 18 opposite, indicates a slightly positively skewed distribution. The histogram in Figure 22 below indicates that the distribution of 𝜃𝑊̃ for heterosexual respondents is slightly positively skewed, although not drastically.
Both the left and center figures show that the distribution of 𝜃𝑊̃ for HeM and HeW is slightly skewed although normally peaked. Friedman's test showed that the rank sum of the stimulus items for the SM rankings before (χ²=3.250, df=5, NS) and after (𝜃𝑥2=4.823, df=5, NS) were not significantly different by sex according to SO Groups.
Additional Analyses
- PAQ Results
- Age
- Race
In the above chi-square analysis, a significant association was found between the androgynous group of the PAQ and homosexuality. However, androgynous and homosexual individuals were significantly concordant in their ranking of SM after the application of a bootstrap (𝜃𝑊̃=0.141, SE 0.059, p≤α=0.05), although not in the original calculation (𝑊̃=0.091, NS). In the chi-square analysis regarding sex by SO group and PAQ classification, the adjusted residuals indicated that there was a specific association between androgyny and HoM in particular.
In the original calculations of 𝑊̃ for white individuals, no significant agreement was found for any of the ranking conditions, as shown in Table 36 below. The initial calculation of 𝑊̃ for respondents of color was not significant for any of the ranking conditions, as shown in Table 38 below.
Discussion, Limitations, and Conclusion
Discussion of Results
- Masculinity and Attractiveness
- Sex and Sexual Orientation
- Additional Analysis
The lack of agreement regarding masculinity, however, may also be due to ambiguity in the masculinity of the stimulus sample itself. The contradiction shown by the Friedman and Kendall tests may be indicative of reduced variance in the stimulus sample. In the analysis of the data regarding sex, women were more concordant than men in their ratings of VA, and men were more concordant than women in their ratings of VM, although the two groups were significantly concordant in both the conditions.
This result was unexpected, as previous psychometric studies of the PAQ have shown that it can correctly discriminate between genders more than 75% of the time (Helmreich et al., 1981). According to Jankowiak et al. 1992), attractiveness ratings are usually influenced by the age of the individual being rated.
Limitations, Recommendations and Conclusions
- Limitations and Recommendations
- Concluding Remarks
Sexual differentiation of the human brain: Relationship to gender identity, sexual orientation, and neuropsychiatric disorders. All future use of the stored data will be subject to further Research Ethics Committee review and approval. Please put the code on the back of the photos in the box corresponding to the ranking of masculinity.
Please enter the code on the t-shirt label in the block corresponding to the attractiveness ranking. Please enter the code on the t-shirt label in the block that corresponds to the masculinity ranking.
