the context of scientiÞc explanation, sexual The Dichotomist reproduction can be deÞned as the union of two reproductive cells, or gametes, which fuse together to Male: Theoretical make a zygote (Krogh 2005). The zygote eventually develops into a fetus and is thus the product of Models of Male successful reproduction. It is important to note that sexual reproduction consists of specialized sex-cells, male and female. These gametes contain the genes of both male and female parents. This combination by Marcelo M. Hanza allows genetic variation by means of crossing over and independent assortment, which in turn provides Completed as a requisite for Psychology of a greater likelihood for the offspring to adapt and Motivation, Spring 2007 survive in its environment (Krogh, 2005; Petri & Govern 2004). The adaptation of a species to its Homosexuality, as it is represented in todayÕs environment as a means of is survival was Þrst culture, is a topic of varied social, political, biological, explained by Charles Darwin (1899) and goes to the psychological and religious controversy. The term heart of the Theory of Evolution. ÒhomosexualityÓ can be deÞned as any sexual Within the framework of Evolution lies the activity between members of the same sex (Tripp principle of Natural Selection, which is deÞned as 1975). In attempt to determine causation or reveal the a process in which the differential adaptation of mechanistic properties involved in homosexuality, organisms to their environment selects those traits two major areas of thought have been derived. The that will be passed on with greater frequency (Krogh ÒnatureÓ view is in the realm of the biological sciences 2005). The process of natural selection in animals and and stresses biological or genetic predispositions humans is carried out through sexual selection, which towards homosexuality. Contrastingly, in the social can be deÞned as a form of nonrandom mating that sciences, there is the ÒnurtureÓ view that stresses produces reproductive success, based on success in psychological and sociological factors leading to obtaining mating partners (Krogh 2005). The principle homosexuality rather than genetic variables. Within of sexual selection infers that members of a species the study of motivation, one of the most fundamental participate in nonrandom mating, which basically and innate factors assimilated into human behavior means that each member of a population is not as is that of sexual reproduction. Sexual reproduction equally likely to mate with another member of the is concerned with passing on oneÕs genetic material, same population (Krogh 2005). From the standpoint in order to perpetuate the survival of oneÕs genes. of evolutionary psychology, males and females exhibit In the natural world, sexual reproduction is just one different strategies in selecting mates. Males posses type of method of reproduction. However, it is the an abundance of reproductive material (sperm) and only source of reproduction available to humans. are more likely to mate with the maximum amount of Identifying both biological and psychological research females in order to pass on his own genes (Petri, pertaining to homosexuality is especially relevant Govern 2004). Contrastingly, females have a to the study of motivation because, interestingly, limited amount of eggs and are much more selective homosexual behavior seems to contradict standard in choosing a mate, as they rely on the success of the theoretical explanations as a major source of production of the zygote in order to pass on their own motivation. This paper will identify and discuss the genetic material. From an evolutionary standpoint, various models of sexual motivation in homosexual humans rely on sexual reproduction as the only males, both from biological and psychological means of genetic continuity and variation. The success viewpoints. of variation can only be accomplished by sexual Before discussing the implications of homosexual reproduction between males and females. However, motivation, it is necessary to identify the advantages the theory of sexual selection does not explain, then, of sexual reproduction, in general. These advantages why males mate with other males or the reason that are relevant due to the homo sapien evolution of a a prevalence of homosexual behavior has not been strictly sexual means of reproduction. Within selected against. There have been theories introduced in biology show that gay and straight men differ in the central pertaining to evolution and ecology which clearly neuronal mechanisms that regulate sexual behavior challenge the Darwinian model of sexual selection. (LeVay 1993). However, LeVayÕs Þndings have been These models are derived from a majority of challenged due to the fact that all of the male subjects ethological research. Joan Roughgarden (2004) had died of AIDS, making it impossible to determine discusses a plethora of examples of homosexual whether the neural tissue was smaller due the viral behavior in mammalian species ranging from infection or due to genetic predisposition. Bighorn sheep to bottle-nosed dolphins to Bonobo One of the major questions pertaining to the monkeys. Darwinism, as it is, seems to have left out origin and causation of homosexuality pertains to a large and legitimate range of species that not only whether or not it is an inherited trait. In a study exhibit homosexual behavior while also participating conducted on monozygotic and dizygotic twins, in successful sexual reproduction. The example scientists found a 52 percent likelihood that a of Bighorn sheep is a perfect example given by male homosexual monozygotic twin would have Roughgarden as a means of evidence in her counter homosexual twin brother. It was also found that argument against sexual selection. there to be a 22 percent likelihood that the dizygotic Bighorn sheep inhabit areas of the Rocky twin would have a homosexual brother (Bailey & Mountains, Montana and Canada. Males, which can Pillard 1991). Evidence concludes that although it weigh up to 300 pounds, associate with females only is likely that there are genetic inßuences on sexual in the breeding season, which extends from mid-fall to orientation, genetics cannot explain early winter. Other than in the breeding season, both as simplistic common inheritance (Murphy 1997). sexes remain exclusively separate. Almost all males engage in homosexual courting and copulation. The Having not found a speciÞed causal link between males who do not participate in homosexual mating genetics and homosexuality, the question arises then, have been labeled by scientists as ÒeffeminateÓ. These why do homosexual behaviors keep resurfacing, ÒeffeminateÓ males do not live with the males, but regardless of heterosexual precursors? Many with the females. These males refuse mounting by developmental, social and clinical psychological other males (Hogg 1984). In this case, the male sheep theories refute the idea that there is a direct genetic who do not exhibit homosexual behavior within their link between heredity and homosexuality. Rather, species are considered deviant. Such examples of these psychological theories seek to identify the species exhibiting homosexual behavior have become various social and relationship roles, along with the more prevalent as more research has been amassed. ideation of sexual orientation, in order to explain A review of biological literature featured more than various motivating factors of homosexual behavior. 100 mammalian species that exhibited homosexual Several theories concerned with subconscious behavior (Bagemihl 1999). Roughgarden holds the drives and motives have been implemented in viewpoint that homosexuality is a variation within a psychology texts, many of them focusing on Freudian limitless range of genetic diversity and is not merely a views of sexual motivation. One of these views is that deviation from heterosexual behavior, but is rather a of the Òcastration complexÓ, which postulates that the legitimate genetic variation. males upon discovering that his mother has no penis, Having addressed the evolutionary theory develops the subconscious fear of losing his own behind sexual reproduction as well as some prevalent penis, which in turn forces him to turn to other men behaviors discussed from ethological observation, for Òsex-with- we are now able to discuss the scientiÞc research safety.Ó This view is still exists among devout conducted with homosexual humans and the followers of Freudian psychoanalysis; other views implications of such research. In a study published range from infantile Þxations to smothering mothers in 1993 by Simone LeVay, LeVay found a difference (Tripp 1975). in size of the interstitial nuclei of the anterior A great deal of psychological literature regarding hypothalamus, a part of the brain more commonly male homosexuality is concerned with the issue of referred to as INAH. After dissecting the brains of masculine identity. Joseph Nicolosi (1991) stressed homosexual and heterosexual men, and heterosexual that the root of male homosexuality was caused by women, LeVay found that one of the interstitial nuclei the inability of the male to fully acquire a masculine known as INAH 3 was, on average, two to three identity. Nicolosi states that it is necessary for the times larger in heterosexual men than in women. male to identify with the father, separate himself He also found that in gay men, INAH 3 was, on from the mother, and renounce his own feminine average, the same size as in the women.The Þndings qualities in order to clearly identify as a male. He

states that this is due to the primal afÞnity that is conserves the speciesÓ (Roughgarden 2004). Should based in shared masculinity between father and son. this be accomplished, will have as Nicolosi identiÞes various factors contributing to the much validity as homosexuality, and in need of just as lack of a masculine identity; these include a more or as little much explanation. rewarding relationship with the mother, the lack of a salient father, the absence of any father, and failure to encourage autonomy. As described by Nicolosi, heterosexual orientation is a bi-product of masculine identiÞcation; homosexual orientation is due to the REFERENCES lack of such identiÞcation. While NicolosiÕs theory appears more valid Bagemihl. (1999). Biological Exhuberance, pp. 269-476. than other psychological theories there is still the question of Òwhat does a masculine identity entail?Ó Bailey, J. Michael & Richard C. Pillard. (1991). A Is it concerned with body size and type, relationships Genetic Study of Male Sexual Orientation. with other males or adequate interest and exhibition Archives of General Psychiatry, 48: 1089-96. in stereotypic male activities? How masculine does one have to feel in order to develop a heterosexual Baird, Robert M. & M. Katherine Baird (Edts). (1995). identity? Aside from this, there is the question Homosexuality: Debating the Issues. NY, NY: regarding the sequence in which masculine identity, Prometheus Books. sexual identity, and behavior establish themselves. For instance, it is not clear if a child develops an identity Darwin, C.R. (1899). On the origin of species by means as a male from his father prior to the development of natural selection (6th edition.). Akron, OH: of sexual urges, or whether the child exhibits sexual Werner. urges prior to identiÞcation with the father. In other words, does gender identity lead to sexual identity Hogg, J.T. (1984). Mating in bighorn sheep: Multiple and further sexual behavior or is one inclined to creative male strategies, Science 225: 526-29. homosexuality prior to the development of gender identity and further sexual identity? Krogh, David. (2005). Biology: A Guide to the Natural These are questions that are difÞcult to answer World (3rd edition.). NJ: Pearson Prentice Hall. due to the difÞculty of testing gender identity or sexual identity. These terms are not rooted in LeVay, Simon. (1993). The Sexual Brain. Cambridge, biological schemas, but are social terms used in MA: MIT Press. identiÞcation and categorization. While biological science is concerned with genetics physiological Murphy, Timothy, F. (1997). Gay Science. NY: structures and mechanisms that may identify Columbia University Press. causation, social science is concerned with the development of relationships and oneÕs interpretation Nicolosi, Joseph. (1991). Reparative Therapy of Male and identiÞcation with social standards and the roles Homosexuality: A clinical Approach. Northvale, that those entail. NJ: Jason Aronson, Inc. In conclusion, the research regarding homosexuality is far from concurring on any Petri, Herbert L., Govern, John M. (2004). Motivation: deÞnitive causal variable. It seems that the sciences Theory, Research, and Applications (5th edition.). are divided on the root of causation- again Nature Belmont, CA: Thompson Wadsworth. vs. Nurture. Both sides have presented theories and conducted research; however, it seems that the Roughgarden, Joan. (2004). EvolutionÕs Rainbow. biological sciences have shown more validity in their Berkley and Los Angles: University of California experimental design and reduction of extraneous Press. variability. The most promising of all theories seems to be the redeÞning of sexual selection theory, as Tripp, C.A. (1975). The Homosexual Matrix. New offered by Roughgarden. This would entail redeÞning York, NY: McGraw-Hill Book Company. the theory of natural selection and its purpose to Òprune the gene pool of bad diversityÓ, in exchange for a diversity-afÞrming view of evolution which functions to Òmaintain the biological rainbow, which