An accumulation of research from around the world finds that societies
which endorse homosexual behavior increase the prevalence of
homosexuality in those societies. The legalization of same-sex
marriage—which is being considered by voters in several US states—is
the ultimate in societal endorsement and will result in more
individuals living a homosexual lifestyle.
Extensive research from Sweden, Finland, Denmark, and the United States
reveals that homosexuality is primarily environmentally induced.
Specifically, social and/or family factors, as well as permissive
environments which affirm homosexuality, play major environmental roles
in the development of homosexual behavior.
A closer look at the research
Twin study investigations of homosexuality were recently conducted in
both Sweden and Finland. Such twin studies compare rates of homosexual
behavior between different sibling groups who share varying degrees of
genetic similarity (ie, identical twins versus non-identical twins).
By comparing such rates, twin studies help sort out the extent to which
homosexual behavior is genetic and/or environmental. For instance, if
homosexuality is genetic, then in cases where one identical twin is
homosexual the co-twin should be homosexual nearly 100 percent of the time
because identical twins share 100 percent of their genes.
But that is not what these two large-scale Scandinavian studies found.
Both studies revealed that when one identical twin was homosexual the
other twin was homosexual only 10 percent or 11 percent of the time. Such findings
indicate that homosexuality is not genetically determined.
of genetic factors, these Scandinavian studies concluded that unique
environmental factors play the largest role in the development of
homosexual behavior. The question as to which specific environmental
factors contribute to homosexuality was not answered by these studies
although some conclusions are offered by Danish and American research
data to be discussed later in this article.
But first, it should be noted that although the Swedish and Finnish
twin studies are among the best to date, they still have wide margins
of error. In fact, the margins of error are so wide it remains entirely
possible that genetic factors play no role in the development of
homosexuality. That remains to be determined, but what has been
resolved is that the primary factor in the development of homosexuality is environmental.
A Danish research investigation studied two million adults living in
Denmark, a country where same-sex marriage has been legal since 1989.
This study uncovered a number of specific environmental factors that
increase the probability an individual will seek a same-sex rather than
an opposite-sex partner for marriage.
For Danish men, the environmental factors associated with higher rates
of homosexual marriage include an urban birthplace and an absent or
unknown father. Significantly, there was a linear relationship between
degree of urbanization of birthplace and whether a man chose homosexual
or heterosexual marriage as an adult. In other words, the more urban a
man’s birthplace, the more likely he was to marry a man, while the more
rural a man’s birthplace, the more likely he was to marry a woman.
For Danish women, the environmental factors related to increased
likelihood of homosexual marriage include an urban birthplace, maternal
death during adolescence, and mother-absence.
this Danish research finds that urban birthplace and separation from
the same-sex parent both were associated with same-sex marriage for men
as well as women. (The latter finding supports psychological theories
that have long asserted homosexuality is related to childhood
problems—real or perceived—with the same-sex parent). In summary, this
study finds that environmental factors that contribute to the development of homosexuality can be social and/or familial.
Finally, an American research study—the most comprehensive and
representative survey of sexual behavior in America—reported its
findings concerning homosexuality. The results of this study also
support an environmental theory of homosexuality, not a genetic one. In
particular, this survey identified specific types of environments
that increase the likelihood of homosexual behavior. The authors
describe these environments as “congenial” to the development of
American men, the environmental factor most related to homosexual
behavior was the degree of urbanization during the teenage years.
Specifically, boys who lived in large urban centers between the ages of
14 and 16 were three to six times more likely to engage in homosexual
behavior than were boys who lived in rural communities during those
same ages. The authors offer the following possibility: “an environment
that provides increased opportunities for and fewer negative sanctions
against same-gender sexuality may both allow and even elicit expression
of same-gender interest and sexual behavior.” Note the word
“elicit.” These researchers believe that growing up in a more
pro-homosexual region may evoke or draw out homosexual behavior in
young men. The implication is that some homosexual men who were reared
in urban centers would not have become homosexual if reared in
non-urban centers. The authors explain, “the environment in which
people grow up affects their sexuality in very basic ways.”
American women, the environmental factor most associated with a
homosexual or bisexual identity was a higher level of education. And
though that was also true for men, the pattern for women was more
dramatic. For instance, a woman with a college degree was nine times
more likely to identify herself as non-heterosexual than a woman with
only a high school diploma. The specific elements that create this
marked difference are unclear, but the researchers don’t believe it’s
simply due to higher reporting of non-heterosexuality by more educated
individuals. They believe one explanation is the fact that with more
acceptance, even encouragement, of homosexuality at universities, more
university women embrace a non-heterosexual lifestyle. For an example
of how that might develop, see Dennis Prager’s article entitled,
“College Taught Her Not To Be a Heterosexual.”
Based on the findings of this American research study, environments that sanction and/or promote homosexuality induce more individuals to engage in homosexual behavior.
All of the aforementioned research studies from
four different countries, each utilizing large, countrywide samples,
reveal that homosexual behavior is not genetically determined. Rather,
the data find that human sexuality is malleable, and environmental
experiences and influences can and do shape its expression. Moreover,
these findings are supported by decades of anthropological and
sociological evidence that reveal that rates of homosexual behavior
fluctuate—sometimes greatly—with changes in the social, cultural, and
legal climate. The more an environment affirms or encourages same-sex
sexuality—whether an urban center or a university campus—the more
homosexuality there will be in that setting.
and cultural norms, as well as legal regulations, influence human
behavior including sexual behavior. So not surprisingly, as the United
States and other Western countries have become increasingly
pro-homosexual—socially, politically, and legally—they have experienced
an upward trend in the number of individuals engaging in homosexual
behavior. That trend will continue if we move beyond mere tolerance of
homosexual behavior (which is appropriate) to formally honoring it by
legalizing same-sex marriage.
Dr Trayce L. Hansen is a licensed psychologist with a clinical and forensic practice in California.
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