Sexual Dimorphism in Human Voice: Female Mate Choice and the Competition for Dominance

Mate choice is a product of mate preferences form in the environment of evolutionary adaptiveness (EEA). Sexual selection suggests that females prefer males who they can gain benefits from such as gifts. This is shown in male birds who make nests for females in order to mate with them and also in insects who give nuptial gifts.

Thus, her breeding span is limited (79). In contrast, for males, it is minimal. He simply must produce sperm cells and go through with an act of copulation, in effect, his reproductive capability is limited by the number of females he mates with (Contrary to popular belief, humans are not a monogamous species but a largely monogamous and partly polgynous species) (Gray 79& 83). In addition, males must play the aggressor role in relationships and are more attracted to physical stimuli (Kanin pg. 71). These all require that males recognize love much more quicker then females (Kanin pg. 71).

Accepted animal mating theory suggests that females tend to select more “attractive” males as their breeding partners. In the case of Túngara frogs from Central America, male “attractiveness” is generally dictated by vocal ability and the size of their vocal sacs. However, a new study reveals that all hope is not lost for males with less desirable songs, thanks to the “decoy” effect.

One aspect that surprised me the most was the claim that men are able to persuade women with their looks, not only because women can be attracted to men but men, essentially, compete with each other. With characteristics like a deep voice, beards, and robust faces; men can effectively intimidate other men in hopes of finding a mate to pass on their genes. I always thought this had to do with attraction, it never crossed my mind that we, humans, took part in this type of competition. Citation #40 can be linked to this because it talks about how having a deeper voice in males may lead women to think men have “good genes” and who would be good fathers - the paper describes it as “paternal investment.” Additionally, men with lower voices can be seen as more dominant to those whose voices are higher in pitch (citation #42).

Sexual Selection is a powerful evolutionary process, for those unable to attract or gain access to the opposite sex, risk being eliminated from the population (Apostolou). The theory of sexual selection was introduced by Charles Darwin in his book The Descent of Man, in which he explains, that selecting a mate is not a random process, and it is key to evolution, for it depends on which individuals have advantage over the rest of the same specie (Stanford 99). In sexual selection, males compete between one another to gain access to a mate, and females choose particular promising mates that demonstrate trait variability, so that their future offspring will have a higher chance of survival (Stanford 99). Male individuals have to demonstrate power, who can conquer the most, ability to survive and provide protection, among other characteristics that will make him the right mate for a female. And Females, must consider their options, since they want high quality genes for their future children (Angeloni 77). Therefore, as a female, I am seeking for specific characteristics in a mate, such as a lean body build, healthy white teeth, and height—he must be over 5’6. I seek for those traits in a mate to further add trait variability in my future offspring, which will help adapt, live longer, and reproduce in the future.

Knowledge gained from animal models of sexually dimorphic neurological structure has provided the impetus for human studies. The first study to report a gross sexual dimorphism in neurological structure examined brain regions responsible for vocal control in songbirds, specifically canaries and zebra finches. The study identified sexual dimorphisms in the hyperstriatum ventrale pars caudale, the robust nucleus of the archistriatum, and an area X of the lobus parolfactorius, all of which are androgen-sensitive areas involved in singing control. Specifically, area X was well developed in both male canaries and male zebra finches, underdeveloped in female canaries, and absent or unrecognizable in female zebra finches. These

Intersexual selection describes one sex (commonly females) choosing male partners for copulation. Females tend to choose the males based on secondary sexual characteristics. Intrasexual selection, on the other hand, is competition within the same sex, in the hope of gaining access to the other sex for reproduction (Eberhard, 1996). It is commonly male species competing against each other for female partners. These two forms of sexual selection results in more developed offspring, as the fitter male will out-compete other males and also is more likely to be chosen be

Still working on the similarities and differences between humans and their ancestries, in Sex at Dawn we can find, for example, a very interesting discussion about human female orgasm, in where the authors of the book point out that female orgasmic behavior has been observed in some primate species with multimale- multifemale mating systems, whereas the monogamous gibbon female does not exhibit such behavior. Following this, Symons’ (1979) by-product argument is summarized, and a few pages later, changes in vaginal

Many researchers believe that certain human traits act as a signpost, advertising the fact that the individual has good genes, or is healthy, or just generally great. As such, finding these traits attractive will result in mating with healthy individuals with good genes. Then evolution kicks in, and the advantages of being attracted to these traits (and possessing them) spread throughout our population until it’s a ubiquitous characteristic of humanity. This is sexual selection. The current study set out firstly to investigate whether the optimum level of men’s facial hair growth and vocal pitch might differ depending on whether we assess attractiveness or dominance. Second, the investigate whether the 2 traits might interact in their effects on attractiveness ratings, such that, for example, higher levels of masculinity in one trait might offset lower levels in the other

Human sexual behavior and how it arose is very puzzling to both scientist and the common people. Many human sexual behaviors have been observed to occur between generations of people, which may show an association with acquired behaviors by evolution. Scientist have tried to analyze the psychological components that constitute sexual human nature and how evolution has shaped them, therefore opening a new branch called Evolutionary Psychology (Sefcek et al., 2 ,2007). Evolutionary Psychology tries to explain how mate choice refers to both conscious and unconscious processes that can be both psychological and physiological (Miller, 88, 1998). An evolutionary approach to mate selection between males and females suggest that mate choice should

To summarize the results of these experiments a number of descriptive statistical measures could be used. As we are most interested in answering questions about what affects mate choice, how mate competition plays out, and how the two may be related though, a few sets of descriptive statistical measures would best serve to characterize our findings with respect to these questions being asked.

Short-term mating, or long-term mating are two of the most important phases that almost every human on this earth would have to go through to reproduce and pass on their genes. Short-term mating and long-term mating can be studied through the evolution of human behavior. Evolution of human behavior allows scientists and researchers to look at human’s relationships, our interaction with each other from routine conversations to the most complicated of human’s interaction in a more profound approach. With movies, music, or any other type of media outlets tend to display lots of subject matter about love and sex, how the idea of short-term mating can lead to successful long-term relationships is absolutely mesmerizing to understand with sexual

For example; men are able to have offspring much easier than women can, and the “costs” of having offspring are not nearly as great for men as they are for women. Women have much more “parental investment” than men. Since the mother of the child only has a few chances to have healthy offspring, if the father leaves or is not attentive and/or caring, the woman’s chances of having healthy offspring that survive to adulthood is greatly reduced. Such for the survival of her potential offspring, and in turn her genes being passed on, it is adaptive for potential mothers to be able to select men and mate with men who will be caring and attentive enough to stick around and help care for and provide for the offspring. Some theories such as in the article “Red, Rank, and Romance in Women Viewing Men” (Francis, 2013) predict that through natural selection, women will have evolved to be “romantically attracted” to men who display these types of traits and qualities. "Women find men more attractive when they are kind, agreeable, intelligent, high in status, emotionally stable, and good-humored.” (Francis,

The changes in allele frequencies help animals adapt to survive and reproduce in an environment. Through natural selection, different species will develop new physical, emotional, and intellectual characteristics to yield a higher fitness in future generations. Also, specific populations of the same geographic area will produce different traits to adapt to that location, such as humans having a higher lung capacity at higher elevations. Thus, the more advantageous qualities will carry on to future generations. Many evolutionary theorists believe that male sexual aggression is one of these dominantly inherited traits. Finding many correlations between human and animal characteristics when it pertains to sexual violence. Research from Primatologists suggests the reasons sexual aggression has become an adaptive trait, as well as why some populations of species do not perform acts of sexual violence.

Robert Trivers, an evolutionary biologist, and Dan Willard, a mathematician and computer scientist, wrote an article in 1973 that suggested an important evolutionary hypothesis regarding sex ratios and parental investment (Trivers & Willard, 1973; Fujita, Roth, Lo, Hurst, Vollner, & Kendell, 2012). This was termed as the Trivers-Willard hypothesis which predicted that natural selection must support unequal parental investment among offspring gender under specific maternal situations and the reproductive potential of her offspring (Fujita, Roth, Lo, Hurst, Vollner, & Kendell, 2012). The Trivers-Willard hypothesis holds three assumptions. The first assumption is that parental condition should predict offspring condition.