by Peter Saunders

Debating issues of sexuality is a political minefield, be it discussing gender differences or asking questions of people’s sexual orientation. As a result there are few serious studies currently under way assessing the causes and consequences of gay lifestyles. Anyone interested in informed debate, must look at all available data as objectively as possible. Christians must also ask how biblical teaching should influence lifestyle choices.

The past decade has seen a growing acceptance of homosexuality and same-sex relationships as part of a range of patterns of behavior within our society.

Psychologists talk about a spectrum of sexual orientation. At one extreme there are people who have never had a homosexual thought in their lives, while at the other are people who feel no arousal towards member of the opposite sex.

Homosexuality may be defined as the preferential erotic attraction to people of the same sex. But putting this definition into practice is not simple, because sexual orientation does not always correlate with sexual behavior and some people with homosexual orientations may never engage in homosexual activity. Conversely, under extreme situations, such as in prisons or during wartime, people with heterosexual orientation may participate in sexual acts with those of the same sex. The usual pattern, however, is that sexual orientation will have a major bearing on sexual expression.

The issue of homosexuality invites Christians to understand people who are often misunderstood. But forming well-founded opinions also involves keeping up to date with contemporary scientific and social research.

Underlying causes

Even asking whether there are underlying causes of homosexuality raises criticism as the very questions is politically incorrect. The result, as one psychiatrist put it, is that ‘This is an area, par excellent, where scientific objectivity has little chance of survival.’(1)

The problem is clearly displayed in a 202 review of the current state of biomedical research on homosexuality. This concluded that so far the causes of homosexuality are unknown, that sexual orientation is likely to be influenced by both biological and social features and that the area could be studied. The review then argued that research into the causes of homosexuality would be unethical and should not occur.(2)

Consequently little work has been carried out recently. A 1997 review of the most likely causes of homosexuality concluded that the scientific study of sexual orientation is, at best, still in its infancy.(3)

Hormonal influences

Some commentators once suggested that homosexuals were hormonally different to heterosexuals. This idea was abandoned when sensitive hormone assays showed that there were no consistent differences.(4)

Prenatal hormonal exposure to sex hormones does influence brain development, giving rise to the possibility that it could affect sexual orientation. Female rats exposed to masculinising androgen hormones, and male rats that are castrated at birth, both show sexual behavior characteristic of the opposite sex.(5)

But extrapolating this to humans is not simple, because unlike the reflex driven behavior of rodents, human sexual behavior is influenced by complex conscious decision-making. If the prenatal hormone hypothesis is correct, studies should find androgen level disorders in homo-sexuals. Extensive reviews of the literature suggest this is not the case.(6)

Brain structure

Some small studies have reported possible correlations between brain structure and sexual orientation, as well as suggesting that homosexual men and women have an increased level of left-handedness. One study reported that an area of the hypothalamus was smaller in women and homosexual men than in heterosexual men,(7) but many commentators have criticised the methods used in the study.(6)

There have been some suggestions that a feature in the barin called the anterior commissure varies in size between heterosexuals and homosexuals. However a 2002 review of the data found that the results of different studies conflicted, and there was no evidence of this variation.(8)


While genes clearly have some bearing on behavior, in the case of homosexuality, the evidence suggests that the genetic influence is only one factor.

There was considerable media interest in 1993, when scientists claimed that variation in a region on the X chromosome (Xq28) was linked to male homosexual orientation.(9) This study has sine met with criticism(10) and few people now give much weight to its evidence.

Twin studies are another way of looking for genetics influences. The most powerful studies look at identical twins who have been separated at birth. A 1986 study of four female and two male pairs concluded that genetic factors were hard to deny, but the numbers of subjects was too small to draw any meaningful conclusions.(11) Also many identical twins have differing sexual orientations.

A 1995 review of the genetic data pointed out that to be valid a study must meet five criteria. It must have:

      1. Valid and precise measure of individual differences
      2. Appropriate methods to determine biological relationships
      3. Randomly selected subjects
      4. Large enough groups of subjects
      5. Correctly understood the underlying genetics.

Its conclusion? ‘To date, all studies of the genetic basis of sexual orientation of men and women have failed to meet one or more of any of the above criteria.'(12) Since then, a study of approximately 3,000 randomly picked people estimated the hereditability of male homosexuality in a range of 0.28-0.65.(13)

Environmental factors

There is evidence that the culture in which a person grows can influence their behavior. At one extreme, in some cultures homosexuality is so uncommon that their language has no word to describe it.

Cambridge psychologist Elizabeth Moberly, suggests that homosexual orientation develops in response to a deficit in early bonding with the same-sex parent. If the child feels unaccepted in the pre-adolescent phase, he or she may look for affirmation in relationship with the same sex once sexual maturity has been reached.(14) There are clearly individuals from such backgrounds who do not develop a homosexual orientation, and others from different backgrounds who do.

Some counsellors find that the majority of male homosexuals that they see identify with this lack of intimate bonding with their fathers or any other male role model.(15)

A study of nearly 35,000 adolescents showed that sexual orientation is not fixed at an early age.(16) In fact, about a quarter of the 12-year-olds were unsure of their orientation. This steadily decline to about 5% of 18-year-olds. The authors noted that the observed relationship between sexuality and religiousity, ethnicity, and socio-economic status provided further evidence of social influences on percieved sexual identity.

Changing Perception

Public and medical reaction to homosexuality has changed dramatically. In the United Kingdom, until 1967 homosexual behavior between consenting adults in private was a criminal offence at any age. In 1973 the American Psychiatric Association removed homosexuality from its list of sexual disorders. Later, The British Medical Association (BMA) Council joined in calls for the lowering of the age of homosexual consent, and in 2000 parliament lowered the age at which a person could legally consent to anal sex for heterosexual or homosexual couples from 18 to 16.(17)

Now that it has become ‘politically correct’ to view homosexual orientation as a normal variant, doctors who express alternative viewpoints are frequently labelled as ‘homophobic’ or ‘heterosexist’.

There has also been a concerted effort to present homosexual orientation as one of many normal biological variants. This has diverted attention away from what homosexual sex involves, and makes homosexuality a topic of everyday conversation. This change of opinion makes it difficult to evaluate the facts objectively, and many people are afraid to contradict it for fear of the wrath of the ‘new establishment’.

Incidence of homosexuality

The true incidence of homosexuality is much lower than generally believed. The commonly quoted figure of ten percent comes from the 1948 Kinsey Report.(18) This was based on a poorly designed study of a non-randomly selected group, 25% of whom were (or had been) prison inmates. A 1994 British sex survey showed that only one in 90 people had a homosexual partner in the previous year.(19) Research published in 2001 indicated that 2.6% of both men and women reported homosexual partnerships.(20)

Despite the popular media image of homosexual monogamy, several large studies reveal that less than ten percent of homosexual men or women have ever experienced a relationship of greater than ten years duration.(21) In one large early study, 74% of male homosexuals reported having more than one hundred partners in a lifetime, and 28% more than 1,000; 75% reported that over half of their partners were strangers. The figures for female homosexuals are substantially lower, but still significantly higher than those for married heterosexual.(22)

Read more: Homosexuality (Part 2)


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