Ovulating Female Preferences to Male Odors in Correlation to Testosterone Levels
Stephanie Cao, Dennis Kephart and Jenna Merrell
Department of Biological Science
Saddleback College
Mission Viejo, CA 92692
Abstract
Evidence suggests that female sexual preference changes throughout the various stages of their menstrual cycle. Their olfactory senses are more sensitive during the ovulation stage. In males, the level of testosterone and pheromone levels are typically directly proportional. This study therefore predicts that an ovulating female’s olfactory preferences would favor a male scent that is higher in testosterone compared to non-ovulating females Need to include more on the groups chosen and how different they were. Females were asked which phase of their menstrual cycle they were currently in as well as their age, and whether they were on birth control or not. They then inhaled and chose the most attractive scent out of fourteen t-shirts worn by different males over a period of one night cycle (eight hours). After a one-tailed unpaired t-test was run, results indicated that preference varied greatly in range and showed that there was no significant difference in ovulating and non-ovulating females’ scent preference in relationship to testosterone level (p=0.133662). according to previous comment, you need to mention here if you the only difference among the groups was ovulation; were the 2 groups equal in number; age. It’s better to put the p-value near the test run for clearance.
Introduction
Females have been shown to have a heightened sense of smell when they are ovulating. Though humans are much less sensitive at sensitive to perceiving smells compared to other mammals, Lord and Kasprzak’s (1989) citation; you can link in to the paragraph although you cite it properly study shows that humans are in fact able to distinguish gender based off scent alone. This is most likely due to the differences in pheromones. During a females’ most fertile period, it has been found that their extra-pair copulations are typically occurring, according to Gangestad and Thornhill’s study done in 1998 cite properly. It has also been found that the male testosterone level has been shown to be directly proportional to his male pheromone production (Iwata et al, 1999). A similar study found that certain molecules can act as pheromones and are used in mate selection, signaling gender, reproductive status as well as competitive ability (Brennan and Kendrick, 2006) explain more and relate to study. It has been shown that males can smell when a female is ovulating as nature’s way of promoting reproduction (Kuukasjarvi et al, 2003). This particular study, however, will see if females prefer a smell higher in testosterone as a way of insuring ensuring “strong” offspring Relate increase in testosterone level and strong offspring; with reference would be better. This could potentially help society further understand the role of scent in mate selection.
Methods
Fourteen males between the ages of 18 and 25 years and twenty menstruating females between the ages of 18 and 50 were used in this study. Subjects were all within the Mission Viejo, California area Need to explain earlier why did you choose this age range; is it significant in you experiment. Also why did you choose males to be 14 and females to be 20. Explain why did a set of ovulating vs. non-ovulating females was assigned one set of males but not the other and try to make a link in the introduction. All data were collected between 8 November and 27 November 2013 either in the homes of the participants or at Saddleback College. Male participants were approached and asked to be in the study ahead of time. When an agreement was reached, male participants were divided into two groups of seven to test over the weekend of 8 November or 15 November for the second group. Over their testing weekend, male subjects were asked to choose one night to shower before bed using Cetaphil brand unscented soap, drool into a Salimetrics collection device, place the vial in the freezer, and then sleep a minimum of eight hours in a Fruit of the Loom brand plain white t-shirt provided on a sheet washed in Purex brand unscented detergent. Male subjects were asked to drool into a separate vial in the morning and return the shirt (in a medium-sized Ziplock bag), sheet and frozen saliva samples Need to cite where you the methods’ idea in introduction. All bags and spit vials were labeled with the participant’s number of 1-7 followed by an “A” if in the first group and “B” if in the second group. They were also asked to fill out a questionnaire asking their age and an approximate number of hours they work out in a week. Need to explain in introduction how would their age and number of hours of working out affect their testosterone; cite as well
Female volunteers were asked to fill out a brief questionnaire asking their age, whether or not they are or have recently been on birth control, if their periods are “regular” and where they are in their menstrual cycle How would birth control affect; Be more specific what aspect of ovulation increases pheromone sensitivity. At what stage of the menstrual cycle were the females?. They were then asked to smell each of the seven shirts from that testing period by cupping the opening of the bag over their nose noses and inhaling deeply. On the questionnaire they were to check the box under the number shirt they most preferred.
On 22 November all spit samples were analyzed with a Salimetrics testing kit for testosterone in the Saddleback College biology laboratory and each male participant was given a numerical testosterone level for both their morning and night samples. These two values were averaged It is needed to explain the method if the article is to be published, since it will be a reference for other scholars. Citation and steps should be introduced in the introduction then explain in methods in details.. Data were input into MS Excel (Microsoft Corporation, Redmond, Washington) in terms of whether the female was ovulating or not and what the numerical testosterone level was of the smell she most preferred. A one-tailed, unpaired t-test was run comparing the preferred testosterone levels of the non-ovulating versus those of the ovulating females.
Results
When a one-tailed, unpaired t-test was run, the results showed no significant increase in ovulating females’ testosterone level preference over that of non-ovulating females (p=0.133662). Males’ average testosterone levels ranged from 52.18 to 219.41, with a group average of 124.95. As shown in Figure 1 below, three out of the fourteen males that were tied for the most number of votes had testosterone levels of 56.49, 79.03, and 219.41. What does this result indicate?
Figure 1. Number of preference votes of both ovulating and non-ovulating females for each of our erase fourteen males’ testosterone levels. Preference varied greatly in range and there was no significant difference in ovulating and non-ovulating females’ preference in relationship to testosterone level (p=0.133662).
This showed that not only did many females (regardless of their current menstrual phase) gravitate towards the same few shirts, but that testosterone level did not play a factor as these values vary greatly in range. One observation worth noting however is that out of the seven females surveyed for the B group, the five that were ovulating all preferred the shirt with a testosterone level of 56.49 and the two non-ovulating preferred various others. This shirt was significantly preferred by ovulating females only what does it indicate according to your references. It was explained earlier that the females were twenty and that females smelled each of the seven shirts from the testing period -clarify..
Discussion
While it was predicted that ovulating females would overall prefer a higher testosterone level than non-ovulating females, results were inconclusive. Past studies, such as Live Science’s (2013) study citation, have shown that females do tend to prefer a scent higher in testosterone when ovulating, however there are so many factors that take play and make it difficult to repeat these results. Their study also entailed that the male volunteers wear the shirts for two consecutive nights, whereas this particular study only had them wear shirts for one eight-hour night period. This might have not been a sufficient time for the natural odor to be fully absorbed.
In a study involving Mediterranean fruit flies (Shelly et. al, 2007), Ceratitis capitata, an experiment was done on mating choice and success based upon male scent. The researchers monitored the female attraction to exposed and non-exposed males to plant structures or essential oils explain similarity of pheromone activity if it is intended to relate two different groups of genetic makeup based upon scent attraction; cite reference . The “perfume effect” used did not have the effect the researchers were hoping on for. Instead, the attraction was based on olfactory differences. This experiment concluded that mating is done through an external phenomenon (possibly alteration of cuticular scent) rather than through internal processing (pheromone synthesis) explain the implication, and cite if possible. In the current study, while researcher researchers tried to minimize these “external” scents by having males shower with unscented soap and sleep on unscented sheets, they could have possibly played a factor and affected the results.
References
Brennan, Peter A. and Keith M Kendrick. 2006. (2006). Mammalian social odours: attraction and individual recognition. Philosophical Transaction of the Royal Society B 361: 2061-2078. Comma between source and volume
Gangestad, Steven W. and Randy Thornhill. 1998. Menstrual cycle variation in women’s preferences for the scent of symmetrical men. Proceedings of the Royal Society B 265 927-933. Comma between source and volume
Iwata, E., Y. Wakabayashi, Y. Kakuma, T. Kikusui, Y. Takeuchi, and Y. Mori. 1999. (1999). Testosterone-Dependent Primer Pheromone in the Sebaceous Gland of Male Goat. Biology of Reproduction 62: 806-810
Kuukasjarvi, Seppo, C.J. Peter Eriksson, Esa Koskela, Tapio Mappes, Kari Nissinen, and Markus J. Rantala. 2006. Attractiveness of Women’s Body Odors Over the Menstrual Cycle: the Role of Oral Contraceptives and Receiver Sex. Behavioral Ecology 15: 579-584.
Lewis, Tanya. 2013. Scent of a Man: Woman Can Sniff out a Hot Guy. Live Science Journal 12: 115-117 .
Lord, Thomas and Mary Kasprzak. 1989. Identification of Self Through Olfaction. Perceptual and Motor Skills 69: 219-224.
Shelly, Todd E., James Edu, Elaine Pahio, and Jon Nishimoto. 2007. Scented Males and
Choosy Females: Does Male Odor Influence Female Mate Choice in the Mediterranean Fruit Fly? Journal of Chemical Ecology 33: 2308-2324.
Review Form
Department of Biological Sciences
Saddleback College, Mission Viejo, CA 92692
Author (s):____Cao, Kephart and Merrell______
Title:_ Ovulating Female Preferences to Male Odors in Correlation to Testosterone
Levels__
Summary
Summarize the paper succinctly and dispassionately. Do not criticize here, just show that you understood the paper.
The investigators did background research regarding the olfactory senses of ovulating versus non-ovulating females and its effect on preferring a higher testerone level as a source of difference in the male pheromones. A group of non-ovualting females and and a group of ovulating females smelled shirts that a group of males, aftering showering using Cetaphil, slept in for min. of 8 hours. Males also drooled into a Samilmetrics collection device before and aftering sleeping. While the investigators predicted that ovulating females would overall prefer a higher testosterone level than non-ovulating females, results, obtained via an unpaired t-test with p-value = 0.13362), showed no significant increase in ovulating females’ testosterone level preference over that of non-ovulating females. Investigators suggest that results could have been altered by the amount of time males slept into the shirts, and the attempt to minimize external scents by having males shower with unscented soap and sleep on unscented sheets.
General Comments
Generally explain the paper’s strengths and weaknesses and whether they are serious, or important to our current state of knowledge.
The paper begins with a very interesting abstract and a good introduction concerning the concept of testosterone effects in males on the pheromones and how ovulating vs. non-ovulating females respond to them, which is an important factor that might come into play to increase or alter the mating depending on the menstrual cycle of females and their responses to pheromones on males in these periods. The study also shows clear graphs and correct tests are run for data analysis.
The paper, however, needs to focus more on transitions between ideas. Since the introduction is the place where investigators plan for the experiment and introduce the reader to the logic behind the experiment and to the methods to be followed with the respective references, so that when published the study would give room for expansion.
The paper is also missing some reasoning to female and male groups division and the age range of test subjects; Also to increase the weight of the data collected differences among hormone levels could be better explained in terms of values in previous studies.
Technical Criticism
Review technical issues, organization and clarity. Provide a table of typographical errors, grammatical errors, and minor textual problems. It's not the reviewer's job to copy Edit the paper, mark the manuscript.
¨This paper was a final version x This paper was a rough draft