Twin studies[ edit ] A number of twin studies have attempted to compare the relative importance of genetics and environment in the determination of sexual orientation. Self reported zygositysexual attraction, fantasy and behaviours were assessed by questionnaire and zygosity was serologically checked when in doubt. Other researchers support biological causes for both men and women's sexual orientation.
Nature versus nurture Certain characteristics may be innate in humans; these characteristics may be modified by the physical and social environment in which people interact.
The sexual drive affects the development of personal identity and social activities. Freud believed sexual drives are instinctive. He was a firm supporter of the nature argument; he said there are a large number of instincts but they are reduced into two broad groups: Eros the life instinctwhich comprises the self-preserving and erotic instincts, and Thanatos the death instinctwhich comprises instincts invoking aggression, self-destruction, and cruelty.
His instinct theory said humans are driven from birth by the desire to acquire and enhance bodily pleasures, thus supporting the nature debate. Freud redefined the term sexuality to make it cover any form of pleasure that can be derived from the human body. His developmentalist perspective was governed by inner forces, especially biological drives and maturation, and his view that humans are biologically inclined to seek sexual gratification demonstrates the nature side of the debate.
A number of them, including neo-analytic theories, sociobiological theories, social learning theorysocial role theoryand script theoryagree in predicting that men should be more approving of casual sex sex happening outside a stable, committed relationship such as marriage and should also be more promiscuous have a higher number of sexual partners than women.
Observed gender differences regarding the number of sexual partners are modest, with males tending to have slightly more than females. They also deal with the influence of biological factors on other aspects of sexuality, such as organic and neurological responses,  heredity, hormonal issues, gender issues, and sexual dysfunction.
As adults, they have different reproductive mechanisms that enable them to perform sexual acts and to reproduce. Men and women react to sexual stimuli in a similar fashion with minor differences. Women have a monthly reproductive cycle, whereas the male sperm production cycle is more continuous.
This is a small area at the base of the brain consisting of several groups of nerve cell bodies that receives input from the limbic system. Studies have shown that within lab animals, destruction of certain areas of the hypothalamus causes the elimination of sexual behavior.
The pituitary gland secretes hormones that are produced in the hypothalamus and itself. The four important sexual hormones are oxytocinprolactinfollicle-stimulating hormoneand luteinizing hormone.
Human male reproductive system Males also have both internal and external genitalia that are responsible for procreation and sexual intercourse. Production of spermatozoa sperm is also cyclic, but unlike the female ovulation cycle, the sperm production cycle is constantly producing millions of sperm daily.
The male genitalia are the penis and the scrotum. The penis provides a passageway for sperm and urine. Two of these bodies lie side-by-side in the upper portion of the penis called corpora cavernosa. The third, called the corpus spongiosumis a tube that lies centrally beneath the others and expands at the end to form the tip of the penis glans.
The urethra runs through the shaft, providing an exit for sperm and urine. The root consists of the expanded ends of the cavernous bodies, which fan out to form the crura and attach to the pubic bone and the expanded end of the spongy body bulb.
The root is surrounded by two muscles; the bulbocavernosus muscle and the ischiocavernosus musclewhich aid urination and ejaculation. The penis has a foreskin that typically covers the glans; this is sometimes removed by circumcision for medical, religious or cultural reasons.
Millions of sperm are produced daily in several hundred seminiferous tubules. Cells called the Leydig cells lie between the tubules; these produce hormones called androgens; these consist of testosterone and inhibin.Brief on Sexual Orientation and Genetic Determinism May Sexual Orientation Bibliography.
Humans display a wide range of sexual feelings and behavior. According to previous research, sexual orientation is influenced to a degree by genetic factors and is therefore heritable but this poses a problem from an evolutionary perspective, because gay.
In a new report, a team of researchers bring the latest science to bear on these issues, providing a comprehensive review of the scientific research on sexual orientation.
The first major scientist to analyze human sexual behavior in the US was Alfred Kinsey. The highlight of their research was the physiological breakdown of the sexual act called the sexual Although researchers believe that environmental influences probably affect sexual orientation, these factors have NOT yet been identified.
According to some theorists love, mating, sexual behavior and sexual orientation are caused and controlled by evolutionary and biological factors. However, other theorists claim that psychological and cultural factors are the key determinants of these patterns of behavior.
Here are details on this /5(4). Factors that influence a child’s response to experiencing sexual behavior problems include: the response and support by the parents and other caregivers following the incident(s) the length of time in which the sexual behaviors take place (sexual behaviors that occur over a .