levy@mtcchi.uucp (2656-Daniel R. Levy(0000000)0000) (07/23/90)
I was just wondering about this when what to my surprise I should come across the topic while passing by sci.bio. (ONLY 500-odd newsgroups left for me to read :-) So I stop to ask a question. Can anyone tell me about any reputable research (i.e. with no axe to grind) that has either conclusively shown or disconfirmed a link between heredity and sexual desire for members of the same sex, in humans? Note please that I am not saying that this would make acting upon that desire _right_ (I believe it is contrary to God's will, and I don't care who flames, I'm just being straight with you, no pun intended). But I seem to recall hearing about research which has shown such a hereditary link. (It involved many pairs of identical twins reared separately from birth, I think.) References to articles that I can get from reputable printed scientific or medical literature would be very welcome. Thank you. -- Daniel R. Levy * Memorex Telex * Naperville IL * ..!uunet!tellab5!mtcchi!levy So far as I can remember, there is not one ... therefore be ye as shrewd word in the Gospels in praise of intelligence. as serpents and harmless as -- Bertrand Russell [Berkeley UNIX fortune] doves -- God [Matthew 10:16]
rob@mtdiablo.Concord.CA.US (Rob Bernardo) (07/27/90)
In article <1990Jul23.022511.28161@mtcchi.uucp> levy@mtcchi.uucp (2656-Daniel R. Levy(0000000)0000) writes: >Can anyone tell me about any reputable research (i.e. with no axe to grind) >that has either conclusively shown or disconfirmed a link between heredity and >sexual desire for members of the same sex, in humans? Has any one either conclusively shown or disconfirmed a link between heredity and sexual desire for members of the opposite sex, in humans? -- Rob Bernardo, Mt. Diablo Software Solutions "If the world were a logical place, men would ride sidesaddle." Rita Mae Brown email: rob@mtdiablo.Concord.CA.US phone: (415) 827-4301
afsipmh@cid.aes.doe.CA (Patrick Hertel) (07/28/90)
In article <1990Jul27.133700.19908@mtdiablo.Concord.CA.US> rob@mtdiablo.Concord.CA.US (Rob Bernardo) writes: >In article <1990Jul23.022511.28161@mtcchi.uucp> levy@mtcchi.uucp (2656-Daniel R. Levy(0000000)0000) writes: >>Can anyone tell me about any reputable research (i.e. with no axe to grind) >>that has either conclusively shown or disconfirmed a link between heredity and >>sexual desire for members of the same sex, in humans? > >Has any one either conclusively shown or disconfirmed a link between >heredity and sexual desire for members of the opposite sex, in humans? >-- >Rob Bernardo, Mt. Diablo Software Solutions >"If the world were a logical place, men would ride sidesaddle." Rita Mae Brown >email: rob@mtdiablo.Concord.CA.US >phone: (415) 827-4301 Seeing as how there would be no heredity to speak of WITHOUT the aforementioned desire, I would think this rather, ahem, conclusive. -- Pat Hertel Canadian Meteorological Centre Analyst/Programmer 2121 N. Service Rd. phertel@cmc.aes.doe.ca Dorval,Quebec Environment Canada CANADA H9P1J3
frazier@oahu.cs.ucla.edu (Greg Frazier) (07/28/90)
In article <1990Jul27.133700.19908@mtdiablo.Concord.CA.US> rob@mtdiablo.Concord.CA.US (Rob Bernardo) writes: +In article <1990Jul23.022511.28161@mtcchi.uucp> levy@mtcchi.uucp (2656-Daniel R. Levy(0000000)0000) writes: +>Can anyone tell me about any reputable research (i.e. with no axe to grind) +>that has either conclusively shown or disconfirmed a link between heredity and +>sexual desire for members of the same sex, in humans? + +Has any one either conclusively shown or disconfirmed a link between +heredity and sexual desire for members of the opposite sex, in humans? Isn't this the same question? What's the point? -- "They thought to use and shame me but I win out by nature, because a true freak cannot be made. A true freak must be born." K. Dunn, _Geek_Love_ Greg Frazier frazier@CS.UCLA.EDU !{ucbvax,rutgers}!ucla-cs!frazier
rdm1@midway.uchicago.edu (russell dean mast) (07/28/90)
In article <37345@shemp.CS.UCLA.EDU> frazier@oahu.cs.ucla.edu (Greg Frazier) writes: >In article <1990Jul27.133700.19908@mtdiablo.Concord.CA.US> rob@mtdiablo.Concord.CA.US (Rob Bernardo) writes: >+In article <1990Jul23.022511.28161@mtcchi.uucp> levy@mtcchi.uucp (2656-Daniel R. Levy(0000000)0000) writes: >+>Can anyone tell me about any reputable research (i.e. with no axe to grind) >+>that has either conclusively shown or disconfirmed a link between heredity and >+>sexual desire for members of the same sex, in humans? >+ >+Has any one either conclusively shown or disconfirmed a link between >+heredity and sexual desire for members of the opposite sex, in humans? > >Isn't this the same question? What's the point? The question is from two viewpoints: one probably heterosexual, and one probably homosexual. (I wish we had a suffix besides "sexual") Both, especially the second, seem, to me, to be laced with distrust and misunderstanding. Perhaps this is all in my head. BTW: Martha McClintock and Jerre Levy have done some relevant work on sexual development, but very little rigorous research has been done on the topic of sexual preference. Uncl Rusfuk. "Robust, Mellow, Satisfying."
jfh@netcom.UUCP (Jack Hamilton) (07/28/90)
In article <1990Jul27.180834.6875@cid.aes.doe.CA> afsipmh@cid.aes.doe.CA (Patrick Hertel) writes: >In article <1990Jul27.133700.19908@mtdiablo.Concord.CA.US> rob@mtdiablo.Concord.CA.US (Rob Bernardo) writes: >>Has any one either conclusively shown or disconfirmed a link between >>heredity and sexual desire for members of the opposite sex, in humans? > > Seeing as how there would be no heredity to speak of WITHOUT the aforementioned >desire, I would think this rather, ahem, conclusive. You're confusing two different desires, that to have children and that to have sex with someone of the other sex. Many gay men and lesbians have children, and many straight couples do not. -- ------------- Jack Hamilton jfh@netcom.uucp
turpin@cs.utexas.edu (Russell Turpin) (07/28/90)
----- In article <1990Jul27.180834.6875@cid.aes.doe.CA> afsipmh@cid.aes.doe.CA >> Seeing as how there would be no heredity to speak of WITHOUT >> the aforementioned [sexual] desire, I would think this rather, >> ahem, conclusive. In article <11095@netcom.UUCP>, jfh@netcom.UUCP (Jack Hamilton) writes: > You're confusing two different desires, that to have children and > that to have sex with someone of the other sex. ... Mr Hamilton is confusing the practicalities of today with the realities that shaped human evolution. Throughout most of the human past, the desire to have children did not mean diddly squat. People copulated for desire or social reason, and lo and behold the kids came along. Planning births or avoiding it was not really a factor. Indeed, there is good reason to think that early humans did not even know the connection between sex and pregnancy. Russell
wolfe@wolves.uucp (Wolfe) (07/29/90)
In article <10615@cs.utexas.edu> turpin@cs.utexas.edu (Russell Turpin) writes: >----- >In article <1990Jul27.180834.6875@cid.aes.doe.CA> afsipmh@cid.aes.doe.CA >>> Seeing as how there would be no heredity to speak of WITHOUT >>> the aforementioned [sexual] desire, I would think this rather, >>> ahem, conclusive. > >In article <11095@netcom.UUCP>, jfh@netcom.UUCP (Jack Hamilton) writes: >> You're confusing two different desires, that to have children and >> that to have sex with someone of the other sex. ... ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unnecessary heterosexism >Mr Hamilton is confusing the practicalities of today with the >realities that shaped human evolution. Throughout most of the >human past, the desire to have children did not mean diddly >squat. People copulated for desire or social reason, and lo and >behold the kids came along. Planning births or avoiding it was >not really a factor. Indeed, there is good reason to think that >early humans did not even know the connection between sex and >pregnancy. > >Russell Sorry to disappoint you, but there are very clear indications in the earliest known records that indicate that the relationship between sex and pregnancy were well known. It is also clear that there was a crude understanding of heredity as well. Early man used selective breeding to modify the animals that were domesticated. The "9 months" period of human gestation was well known in early records. *OPINION* Just because the sexual immaturity of modern america leads many people to be unaware of their own bodies, we should not assume that "early humans" did not know about sex. There are some indications in early writings that there was a (suprizing to the modern mind) level of sophistication in terms of sexual and procreational knowledge in several places and times. Additionally, homosexuality could persist in the gene pool via several mechanism that have nothing to do with its supposed effect on reproductive success. It could be a recessive, multi-linked trait that follows along with some strongly conserved gene. It could re-arise as a spontaneous mutation in a manner similar to one form of hemophilia that is a single base-pair transcription error. It could confer some kind of reproductive advantage in a manner analagous to the protection that sickle-cell trait provides against malaria. This discussion is fairly feckless anyways, since there is no convincing proof either way as to a genetic basis for all forms of homosexual behaviour. -- G. Wolfe Woodbury @ The Wolves Den UNIX, Durham NC UUCP: ...dukcds!wolves!wolfe ...mcnc!wolves!wolfe [use the maps!] Domain: wolfe%wolves@mcnc.mcnc.org wolfe%wolves@cs.duke.edu [The line eater is a boojum snark! ] <standard disclaimers apply>
geoffp@cup.portal.com (Geoffrey Scott Puterbaugh) (07/30/90)
In response to Daniel Levy's request for reputable
research into a possible link between heredity and sexual
desires for members of the same sex...
Mr. Levy:>> Note please that I am not saying that this
would make acting on that desire _right_ ... I believe it is
contrary to God's will, and I don't care who flames...
Such irrelevant twaddle has no place on sci.bio, and
makes me wonder how sincere you are in asking for "reputable
research." But you get a reply anyway. :-)
For better or worse, I have a book coming out next
month on this subject ("Twins and Homosexuality: A
Casebook," Garland Publications, NY, should be August 1990).
You asked for references to articles. I have put them at the end.
What follows is a summary of what appears in the
periodical literature.
The concordance rate for homosexuality among male MZ (identical)
twins is the interesting number addressed by these studies.
If the theory of environmental causation were true, then one
would expect no concordance for homosexuality at all; that
is, homosexuals would appear at the basic Kinsey rate of 5
to 10 per cent of the male population.
But that is not the number which medical research gives
us. If we add up all the pairs reported in these eight
articles (including those summarized in Zuger and in Heston
and Shields), we obtain the following totals: 65 pairs of
male MZ twins, 50 of whom are concordant and 15 discordant.
This amounts to 77 per cent concordance among identical male
twins. (Out of caution, this count excludes all females and
all cases where schizophrenia was present.)
Furthermore, if we eliminate the recent spate of
"freak" articles -- articles published to study the puzzling
case of discordant MZ twins, and which have a sample size of
one discordant pair -- we are left with 37 from Kallmann, 2
from Lange, 6 from Sanders, 5 from Habel, 4 from Heston and
Shields, 1 from Farber, and 2 from Eckert and Bouchard.
This makes 57 pairs, 50 of whom are concordant, and 7 of
whom are discordant. Analyzed in this way, the data would
seem to suggest a concordance rate of about 88 per cent for
homosexuality among male identical twins.
The true concordance rate is not yet known. If it
should prove to be as high as 80 or 90 per cent, then it
would probably be enough to settle the nature/nurture
debate. This conclusion may seem startling, since many
people believe that even one discordant MZ pair must
disprove the entire genetic case. Identical twins have
identical genes: if they are discordant in regard to
homosexuality, then clearly something else is at work.
The error in such reasoning lies in a faulty
assumption, which is pointed out by two authors, Money and
Klintworth: we already know that MZ twins are not
necessarily identical in their gene complements. This has
appeared in cases of MZ twins discordant for Down's syndrome
and Turner's syndrome. Slight differences in the genotype
can and do occur in ways which we are trying to determine
(even Gregor Mendel has been rightly faulted for doctoring
his pea studies to obtain exact ratios, where nature was not
quite so exact). And this very slight difference may well
be the mechanism which makes the concordance rate for male
homosexuality less than 100%.
We must, given these figures for MZ twin pairs, compare
them to the figures for DZ (fraternal) twins.
The DZ twin pairs show no
concordance at all for homosexuality, or a very slight
concordance. In every case so far known to medical
research, the DZ concordance rate has been so much lower
than the MZ concordance rate that the DZ rate has generally
been compared to the rate for siblings. And the DZ rate is
consistent, whether the DZ twins were raised together or
apart.
Since both DZ and MZ twins are usually raised together
in the same environment, the champions of an environmental
etiology are, rightly, puzzled.
In any case, the numbers from these twin studies are
obviously much too high to allow any further credence to be
given to theories of exclusively environmental causation.
--------------
It is very hard to write about this subject, because
news is coming in all the time. A Canadian group just now
claims to have discovered that homosexual men *and* women
are disproportionately left-handed. Vast anecdotal evidence
claims that the great majority of woodwind players and
organists are gay men. What is going on?
This much seems fairly certain right now: there is no
"period of choice" -- for choosing homo, hetero, or bi.
Everyone seems to be looking at genetic factors or at events
within the womb before birth. The "events within the womb"
group needs to look at the numbers from the twin studies,
because both MZ and DZ twins share the same womb -- but
somehow the MZ twins emerge from the womb much more
concordant in their sexuality than the DZ twins.
I hope this is helpful in enabling you to make up your own
mind on the question, or in beginning to research the question
on your own. Right now, my own impression is that human
sexuality is built upon a very strong genetic foundation which
is probably modifiable by hormonal events within the womb. But
the question is decided, for most people, at or before birth.
So finger-pointing is not a reasonable activity.
Partial bibliography (significant articles in the
literature, send me e-mail if you want a more complete
bibliography of around 200 items)
Kallmann, F.: "Comparative Twin Study on the Genetic
Aspects of Male Homosexuality," The Journal of Nervous and
Mental Disease, v. 115, pp. 283-98 (1952).
Rainer, J.D., Mesnikoff, A., Kolb, L.C. and Carr, A.:
"Homosexuality and Heterosexuality in Identical Twins,"
Psychosomatic Medicine, v. 22, pp. 251-59 (1960).
Klintworth, G.K.: "A Pair of Male Monozygotic Twins
Discordant for Homosexuality," The Journal of Nervous and
Mental Disease, v. 135, pp. 113-25 (1962).
Heston, L.L. and Shields, J.: "Homosexuality in Twins:
A Family Study and a Registry Study," Archives of General
Psychiatry, v. 18, pp. 149-60 (1968).
Zuger, B.: "Monozygotic Twins Discordant for
Homosexuality: Report of a Pair and Significance of the
Phenomenon," Comprehensive Psychiatry, v. 17, pp. 661-69
(1976).
McConaghy, N. and Blaszczynski. M.A.: "A Pair of
Monozygotic Twins Discordant for Homosexuality: Sex-
Dimorphic Behavior and Penile Volume Responses," Archives of
Sexual Behavior, v. 9, pp. 123-131 (1980).
Ruse, M.: "Are There Gay Genes? Sociobiology and
Homosexuality," The Journal of Homosexuality, v. 6, pp. 5-34
(1981).
Eckert, E.D., Bouchard, T.J., Bohlen, J. and Heston,
L.L.: "Homosexuality in Monozygotic Twins Reared Apart," The
British Journal of Psychiatry, v. 148, pp. 421-425 (1985).muttiah@cs.purdue.EDU (Ranjan Samuel Muttiah) (07/30/90)
In article <10615@cs.utexas.edu> turpin@cs.utexas.edu (Russell Turpin) writes: >realities that shaped human evolution. Throughout most of the >human past, the desire to have children did not mean diddly >squat. People copulated for desire or social reason, and lo and >behold the kids came along. Planning births or avoiding it was >not really a factor. Indeed, there is good reason to think that >early humans did not even know the connection between sex and >pregnancy. As long as it helped in their survival, why should they ? It might be interesting that the pygmy mongooses located in parts of Africa may have something to teach us. They live in closely knit groups and only one female is allowed to reproduce. The rest, male and female, are somehow (instinct ?) condemned to a life of looking after the growing little ones. They live in ant hills and the care takers spend their life looking out for potential predators. They have really excellent tactics and signals of communication to avert impending danger. In fact, even food priorities are such that the little ones have the first choice. Now here are a of smart bunch of rodents if ever I saw one :-).
turpin@cs.utexas.edu (Russell Turpin) (07/30/90)
----- I wrote: >> Mr Hamilton is confusing the practicalities of today with the >> realities that shaped human evolution. Throughout most of the >> human past, the desire to have children did not mean diddly >> squat. People copulated for desire or social reason, and lo and >> behold the kids came along. Planning births or avoiding it was >> not really a factor. Indeed, there is good reason to think that >> early humans did not even know the connection between sex and >> pregnancy. In article <1990Jul29.050038.24791@wolves.uucp>, wolfe@wolves.uucp (Wolfe) writes: > Sorry to disappoint you, but there are very clear indications in the > earliest known records that indicate that the relationship between sex > and pregnancy were well known. I fully realize that ancient cultures knew the basic facts of reproduction. But the past five or six thousand years during which we have written records is only the small tail-end of the few hundred thousand years during which humans have existed. Somewhere between the development of language and the later development of written records and "ancient" cultures, our ancestors discovered the relation between sex and babies. Some changes that archeologists see in *prehistoric* carvings are interpreted (speculatively) to signal this discovery. But even if this interpretation is entirely offbase, the window does not provide much time for great evolutionary change. Something had to cause the early humans and proto-humans to reproduce, and this something is undoubtedly sexual desire. It might have changed some since then, but I doubt it has changed drastically. Russell
john@anasaz.UUCP (John Moore) (07/30/90)
In article <32214@cup.portal.com> geoffp@cup.portal.com (Geoffrey Scott Puterbaugh) writes:
] The true concordance rate is not yet known. If it
]should prove to be as high as 80 or 90 per cent, then it
]would probably be enough to settle the nature/nurture
]debate. This conclusion may seem startling, since many
]people believe that even one discordant MZ pair must
]disprove the entire genetic case. Identical twins have
]identical genes: if they are discordant in regard to
]homosexuality, then clearly something else is at work.
]
] The error in such reasoning lies in a faulty
]assumption, which is pointed out by two authors, Money and
]Klintworth: we already know that MZ twins are not
]necessarily identical in their gene complements. This has
]appeared in cases of MZ twins discordant for Down's syndrome
]and Turner's syndrome. Slight differences in the genotype
]can and do occur in ways which we are trying to determine
](even Gregor Mendel has been rightly faulted for doctoring
]his pea studies to obtain exact ratios, where nature was not
]quite so exact). And this very slight difference may well
]be the mechanism which makes the concordance rate for male
]homosexuality less than 100%.
Thank you for the excellent, factual posting. Another possibility
for the discordance is that there are different
kinds of homosexual personalities, with different causes.
There might be a genetic homosexual persuasion, and there might also
be an environmental one. Is there any research that seeks to
separate these two groups, and possibly differentiate them
on grounds other than sexual preference (such as aesthetic
ability, handedness, etc)?
Another, more general question about twin studies: is the
tendency to have twins hereditary? If so, does this mean that
some twin studies might be biased due to traits linked to
the twinning trait?
--
John Moore HAM:NJ7E/CAP:T-Bird 381 {ames!ncar!noao!asuvax,mcdphx}!anasaz!john
USnail: 7525 Clearwater Pkwy, Scottsdale,AZ 85253 anasaz!john@asuvax.eas.asu.edu
Voice: (602) 951-9326 Wishful Thinking: Long palladium, Short Petroleum
Opinion: Support ALL of the bill of rights, INCLUDING the 2nd amendment!afsipmh@cid.aes.doe.CA (Patrick Hertel) (07/30/90)
In article <11095@netcom.UUCP> jfh@netcom.UUCP (Jack Hamilton) writes: >In article <1990Jul27.180834.6875@cid.aes.doe.CA> afsipmh@cid.aes.doe.CA >(Patrick Hertel) writes: >>In article <1990Jul27.133700.19908@mtdiablo.Concord.CA.US> >rob@mtdiablo.Concord.CA.US (Rob Bernardo) writes: >>>Has any one either conclusively shown or disconfirmed a link between >>>heredity and sexual desire for members of the opposite sex, in humans? >> >> Seeing as how there would be no heredity to speak of WITHOUT the aforementioned >>desire, I would think this rather, ahem, conclusive. > >You're confusing two different desires, that to have children and that to >have sex with someone of the other sex. Many gay men and lesbians have >children, and many straight couples do not. >-- >------------- >Jack Hamilton >jfh@netcom.uucp So if no-one had sexual desires for the opposite sex..... I think my point still stands. -- Pat Hertel Canadian Meteorological Centre Analyst/Programmer 2121 N. Service Rd. phertel@cmc.aes.doe.ca Dorval,Quebec Environment Canada CANADA H9P1J3
daryl@oravax.UUCP (Steven Daryl McCullough) (07/30/90)
In article <32214@cup.portal.com>, geoffp@cup.portal.com (Geoffrey Scott Puterbaugh) writes: > > In response to Daniel Levy's request for reputable > research into a possible link between heredity and sexual > desires for members of the same sex... > [...interesting summaries of study results deleted...] The studies you cite are very interesting, and convincingly argue against the notion that sexual preference is determined by a child's environment in the first few years of life. However, I don't think that sexual preference is understood well enough for anyone to say that we *know* that it has a genetic cause. Until a mechanism is identified, the studies such as the ones you can only be taken as only data, not as any kind of proof. Do we even know what sexual preference is? Is it preference for partners with particular body types? Or personality types? Or sex organs? Or chromosomes? Is it heterosexual or homosexual for a man to be attracted to a newly-female transsexual? What about the small percentage of people who say that they don't enjoy any kind of sex---are they heterosexual or homosexual or asexual? Daryl McCullough
jag@cello.mc.duke.edu (John Graves) (07/30/90)
In article <1990Jul29.050038.24791@wolves.uucp> wolfe@wolves.UUCP (Wolfe) writes: In replying to a previous article which noted that >>Mr Hamilton is confusing the practicalities of today with the >>realities that shaped human evolution. Throughout most of the >>human past, the desire to have children did not mean diddly >>squat. People copulated for desire or social reason, and lo and >>behold the kids came along. Planning births or avoiding it was >>not really a factor. Indeed, there is good reason to think that >>early humans did not even know the connection between sex and >>pregnancy. >> >>Russell Wolfe answers: > Sorry to disappoint you, but there are very clear indications in the >earliest known records that indicate that the relationship between sex >and pregnancy were well known. > It is also clear that there was a crude understanding of >heredity as well. Early man used selective breeding to modify the >animals that were domesticated. The "9 months" period of human >gestation was well known in early records. > >*OPINION* > Just because the sexual immaturity of modern america leads many >people to be unaware of their own bodies, we should not assume that >"early humans" did not know about sex. There are some indications in >early writings that there was a (suprizing to the modern mind) level of >sophistication in terms of sexual and procreational knowledge in several >places and times. > It is common among creation scientists to think of the world as relatively young and human history as filling quite a bit of that creation. It should be apparent to most that the period called history is quite small in regard to that known as prehistory. Even the most conservative of estimates about the existence of homo sapiens places the beginning period back tens of thousands of years. While there have certainly been paradigm shifts during recorded history which makes misreadings of early human records, for all intents and purposes here, any human record or writing is that of later human beings. Truly early humans cannot be judged on the basis of any symbolic artefacts that are known to exist at this time. If we are to assume that man or woman understood the gestation period from first consciousness we are making a creationist assumption. Knowledge of this sort needed to have been learned in a trial and error method and may have been passed down through oral traditions once known. But it would also have been necessary to have an understanding of time to do this. It is highly unlikely that early humans knew what nine months were and while they may have noticed a time correlation with pregnancy they would not have thought it nine months from conception since there would have been no apparant connection with copulation and increasing size that would have signified the coming of birth in the future. Humans would have had to have been fairly sophisticated to make a connection between one act of copulation and gestation since it is likely that several acts of copulation may have followed the fateful one. For all we know record keeping may have come about because of the need to plan births but highly unlikely. We simply do not know anything about the sexual practices of early humans other than that heterosexual sex occurred. It is highly likely that homosexual experiences occurred too. In fact it may be that early men were constantly having sex in all combinations since it appears that primates and humans naturally engage in large amounts of homosexual sexual experiences. Natural here meaning that it occurs. It may indeed be that original male human behavior can be expressed as "fuck it if it moves". Replies may be made to JAG@CELLBIO.DUKE.EDU
cam@aipna.ed.ac.uk (Chris Malcolm) (07/31/90)
In article <10615@cs.utexas.edu> turpin@cs.utexas.edu (Russell Turpin) writes: >Indeed, there is good reason to think that >early humans did not even know the connection between sex and >pregnancy. Not just early humans. A fairly recent model (female, ~60 yrs old) told me quite seriously that at the time she had her first child she still beleived that kissing made you pregnant. Her parents had told her nothing, and this supposition was current amongst her girl friends. Well, maybe she was naive and they were pulling her leg; but maybe they were equally ignorant, but had noted the undoubted statistical correlation -- i.e., of all their friends, only those who hadn't kissed a man hadn't got pregnant. -- Chris Malcolm cam@uk.ac.ed.aipna 031 667 1011 x2550 Department of Artificial Intelligence, Edinburgh University 5 Forrest Hill, Edinburgh, EH1 2QL, UK
rozin@speedy.cs.pitt.edu (Roman Rozin) (07/31/90)
In article <1619@oravax.UUCP> daryl@oravax.UUCP (Steven Daryl McCullough) writes: >In article <32214@cup.portal.com>, geoffp@cup.portal.com (Geoffrey Scott Puterbaugh) writes: [ studies implying genetic basis for homosexuality ] > However, I don't think >that sexual preference is understood well enough for anyone to say >that we *know* that it has a genetic cause. Until a mechanism is >identified, the studies such as the ones you can only be taken as >only data, not as any kind of proof. It is not necessary to know the particular mechanism, to know that there is *some* mechanism at work there. There are cases of homosexual behavior in lower animals too. For examle, lesbian gulls, described in R.L. Trivers's _Social Evolution_. Roman Rozin
sbishop@desire.wright.edu (07/31/90)
In article <10654@cs.utexas.edu>, turpin@cs.utexas.edu (Russell Turpin) writes: > ----- > I wrote: >>> Mr Hamilton is confusing the practicalities of today with the >>> realities that shaped human evolution. Throughout most of the >>> human past, the desire to have children did not mean diddly >>> squat. People copulated for desire or social reason, and lo and >>> behold the kids came along. Planning births or avoiding it was >>> not really a factor. Indeed, there is good reason to think that >>> early humans did not even know the connection between sex and >>> pregnancy. > > In article <1990Jul29.050038.24791@wolves.uucp>, wolfe@wolves.uucp (Wolfe) writes: >> Sorry to disappoint you, but there are very clear indications in the >> earliest known records that indicate that the relationship between sex >> and pregnancy were well known. > > I fully realize that ancient cultures knew the basic facts of > reproduction. But the past five or six thousand years during > which we have written records is only the small tail-end of the > few hundred thousand years during which humans have existed. > Somewhere between the development of language and the later > development of written records and "ancient" cultures, our > ancestors discovered the relation between sex and babies. > This may be true of some cultures but I am fairly sure that the Aborigines in Australia did not make the connection before European settlers came. I remember reading an article that described their beliefs and connected production of a child with a spirit of some physical part of their environment. > Some changes that archeologists see in *prehistoric* carvings are > interpreted (speculatively) to signal this discovery. But even > if this interpretation is entirely offbase, the window does not > provide much time for great evolutionary change. Something had to > cause the early humans and proto-humans to reproduce, and this > something is undoubtedly sexual desire. It might have changed some > since then, but I doubt it has changed drastically. It has been speculated by anthropologists that at some time in the distant past the majority of societies were matriarchal and that the male's role in conception was misunderstood or ignored. As for sexual desire being the main impitous for reproduction, well, it works for the other animals..... ;-)
mls@cbnewsm.att.com (mike.siemon) (07/31/90)
In article <21096@duke.cs.duke.edu>, jag@cello.mc.duke.edu (John Graves) writes: > Truly early humans cannot be judged on the basis of any symbolic artefacts > that are known to exist at this time. If we are to assume that man or woman > understood the gestation period from first consciousness we are making a > creationist assumption. I think you are mistaking Mr. Wolfe's point, which I hardly took to be a creationist one. Indeed, I made the same point in email. To the (quite limited, as you rightly observe) extent we *have* evidence, the connection is known. That of course cannot carry back so far that the idea of *any* conscious associations becomes problematic. But the *assumptions* being made (not necessarily by Mr. Turpin, who is generally circumspect, but by most of our contemporaries), without any evidence at all, are that heterosexual desire in humans needs no explan- ation. That is hardly the case. The fact is we *don't* know a damn thing about the biopsychological basis of human sexuality, or much at all about its social patterning -- even today, let alone in a past so far distant that it becomes a question what was similar and what wasn't. > We simply do not know anything about the sexual practices of early > humans other than that heterosexual sex occurred. This, at least, seems to be a reasonably sound statement. :-) All the rest of your contribution is the merest speculation. And by mulling over such speculations one may come up with ideas for empirical tests, maybe even ones that can apply to old data, or by careful comparatives apply to "all primates" or some such class. But untested speculation tends to be uncontrolled projection of ideologies -- witness the 19th century speculations about "race." What I would seriously urge is that our current "ideas" about sexuality (hetero- and homo-) may be quite as much without empirical foundation as the earlier notions of race. The argument that "of course people were heterosexual or we wouldn't be here" is either tautologically inane or totally devoid of evidence. -- Michael L. Siemon "I cannot grow; m.siemon@ATT.COM I have no shadow ...!att!sfsup!mls To run away from, standard disclaimer I only play"
mwfolsom@hydra.unm.edu (Mike Folsom) (07/31/90)
In article <8250@pitt.UUCP> rozin@speedy.cs.pitt.edu.UUCP (Roman Rozin) writes: > >It is not necessary to know the particular mechanism, to know that there >is *some* mechanism at work there. There are cases of homosexual behavior >in lower animals too. For examle, lesbian gulls, described in >R.L. Trivers's _Social Evolution_. I was just about to add this to the discussion. There ARE cases of what can be called homosexuality in various groups of animals other than man. I have heard of reports in cattle ( can you imagine buying a $20,000 gay bull ) and insects. Infact there is a mutation called "rape" in the fruit fly where a male tries to mount and copulate with another male. I really don't like the name "rape" for this mutation but it exists. To add my two cents. I have been keeping an informal record fo MZ lesgay twins for years. So far out of about 6 MZ twins I have found only one who "says" that his brother is straight. I'm starting to wonder if homosexuality isn't a mix of genetics and environment. This is not my area but I've always wondered about pheromones and if they have any involvement in the whole process. I believe in some group of animals it has been shown that males and females emit different pheromones. WHAT IF ( and I admit its a big if ) males usually are attracted to one set of pheromones, those of the females, and females to another set, those of the males. If such a thing were true then any change in the human genome which caused a change in the ability to perceive a pheromone or, alternately, any change in the genome that would cause an individual to be only attracted to "self" pheromone could affect their sexual orientation. In a similar vein if the change simply destroyed the ability to perceive a pheromone or caused an individual to be attracted to all pheromones then they could be bisexual. Since Kinsey (sp) said, as I remember the numbers, that most people are bisexual then most folks would "key in" on both "sets" of pheromones. Which one attracted them the most would be the one that would "control" their sexual orientation. Anyway, as I said this is not my area but I've been thinking about this for some time. Comments, corrections, etc - Now, be kind! Mike F. (mwfolsom@unmvm -=-or-=- mwfolsom@unmvm.unm.edu)
dhinds@portia.Stanford.EDU (David Hinds) (07/31/90)
In article <32214@cup.portal.com> geoffp@cup.portal.com (Geoffrey Scott Puterbaugh) writes: > > The concordance rate for homosexuality among male MZ (identical) >twins is the interesting number addressed by these studies. >If the theory of environmental causation were true, then one >would expect no concordance for homosexuality at all; that >is, homosexuals would appear at the basic Kinsey rate of 5 >to 10 per cent of the male population. > > But that is not the number which medical research gives >us. If we add up all the pairs reported in these eight >articles (including those summarized in Zuger and in Heston >and Shields), we obtain the following totals: 65 pairs of >male MZ twins, 50 of whom are concordant and 15 discordant. >This amounts to 77 per cent concordance among identical male >twins. (Out of caution, this count excludes all females and >all cases where schizophrenia was present.) > > The true concordance rate is not yet known. If it >should prove to be as high as 80 or 90 per cent, then it >would probably be enough to settle the nature/nurture >debate. This conclusion may seem startling, since many >people believe that even one discordant MZ pair must >disprove the entire genetic case. Identical twins have >identical genes: if they are discordant in regard to >homosexuality, then clearly something else is at work. > > We must, given these figures for MZ twin pairs, compare >them to the figures for DZ (fraternal) twins. The DZ twin pairs >show no concordance at all for homosexuality, or a very slight >concordance. In every case so far known to medical >research, the DZ concordance rate has been so much lower >than the MZ concordance rate that the DZ rate has generally >been compared to the rate for siblings. And the DZ rate is >consistent, whether the DZ twins were raised together or >apart. Is the MZ concordance rate consistent, whether raised together or apart? I doubt that there is enough data to tell. Sampling biases also seem to be frequent problems in twin studies of all kinds, and I would view all small twin studies with caution. The standard argument against explaining MZ concordances as evidence of genetic linkage is that MZ twins are thought to have much more similar environments than DZ twins. If DZ twins and siblings really do show almost no concordance, then the data would imply that sexual preference is controlled by sufficiently many genes that a sibling's 50% genetic identity has no predictive power for the trait. It would also indicate the absence of any significant environmental influences. While the absence of any major gene effects tends to be the rule for complex human characteristics, this is usually accompanied by substantial environmental effects. All genetic character- istics are modulated by environmental influences to some degree; it would be strange for such an apparently complex trait (as judged by MZ vs DZ, taken at face value) to show no environmental influence (as judged by DZ vs. population average). -David Hinds dhinds@popserver.stanford.edu
david@gladys.UUCP (David Dalton) (07/31/90)
>In article <8250@pitt.UUCP> rozin@speedy.cs.pitt.edu.UUCP (Roman Rozin) writes: >Since Kinsey (sp) said, >as I remember the numbers, that most people are bisexual then most >folks would "key in" on both "sets" of pheromones. Which one >attracted them the most would be the one that would "control" their >sexual orientation. For AGES I have been looking for a study on pheromones and sexual orientation, but so far I haven't found anything. It would appear to be a really fruitful area for study. For example, we know that people who lose their sense of smell (nasal polyps, brain problems, etc.) often lose interest in sex. But mainly the idea intrigues me because of one of my earliest memories. I was about five years old. Our neighbors' washing machine had broken down, and they were doing laundry in our basement. I remember being in the basement alone and seeing their laundry, neatly sorted, in piles on the floor. There were two teen-age daughters and one teen-age son in the household. I didn't have the slightest curiosity about the girls' clothing, but I was very curious about the boy's. I picked up his jeans and sniffed them very thoroughly, and I found it very exciting in a way that I did not at all understand. I believe that, long before I understood sex and sexuality, this experience showed that I was already thoroughly oriented toward males, and that scent is an important cue. These sorts of things happen on a very low level, mostly beneath consciousness, but I have tried to make myself as aware as possible of my reactions to other people's scents. If someone I like walks by, I often time my breathing to take in their scent. If someone I don't like, or who I find repulsive in some way, walks by, I often hold my breath so I won't have to smell them. If I like a woman, I do enjoy her scent, but I don't find it erotically stimulating. I've been helplessly in love with a co-worker for five years. He's been dealing with a lot of stuff, but he's getting there. (Remember this one, Jess?) I think that the smell of him in close quarters is more tantalizing to me than the sight of him. And, to make things really difficult, he's in my house a lot these days, and he does his laundry here every week. I can't tell you what it does to me to come in and find his tennis things in the laundry room, waiting for him to come back and finish up. Or, when he house-sits for me, to come home to the scent of him in my bed. Or hot and sweaty, moving a bookcase. Or arriving after a long bicycle ride. What sweet torture... -- David Dalton pacbell!gladys!david mcnc!gladys!david
bill@uhccux.uhcc.Hawaii.Edu (William J. King) (08/01/90)
In article <1990Jul23.022511.28161@mtcchi.uucp> levy@mtcchi.uucp (2656-Daniel R. Levy(0000000)0000) writes: > >Can anyone tell me about any reputable research (i.e. with no axe to grind) >that has either conclusively shown or disconfirmed a link between heredity and >sexual desire for members of the same sex, in humans? Do you really believe there is a genetic marker for such? then ought there to be a genetic marker for hererosexuality, abstinence? the white coats claim there is a genetic marker for crime. Unreal, imagine being tested at birth and labeled WITHOUT an avenue of renouncing such. The political consequences of genetic labeling are scarey. these questions ought not to be asked. Imagine if genetic claims were genaralized across an ethnic group (as science did in the 19th century to justify rascism). consider the public policy and expenditures that would be implemented. scary! bill bill@uhccux.bitnet bill@uhccux.uhcc.hawaii.edu 21.3 LAT by 157.9 LONG
sfm@cbnewsl.att.com (stephen.frank.mershon) (08/01/90)
In article <1990Jul31.012219.3299@ariel.unm.edu>, mwfolsom@hydra.unm.edu (Mike Folsom) writes: > > [various speculation on possible factors in sexual orientation] Much research has been done in this field. If you are interested in knowing what the experts say, send $1 and a large, self-addressed, stamped envelope to PFLAG, P.O. Box 20308, Denver, CO 80220. Ask for the pamphlet "Why Is My Child Gay?". This pamphlet summarizes the views of 11 leading scientists and provides a reading list referencing nine major published studies on the subject. To summarize a few of the findings: - the exact causes of a particular orientation are unknown - orientation is likely the result of interaction of genetic, hormonal, and environmental factors - psychological and social influences alone cannot cause a particular orientation - a biological predisposition toward a particular orientation is present at birth in all people - orientation cannot be changed permanently through therapy Steve Mershon stephen.mershon@att.com
rob@mtdiablo.Concord.CA.US (Rob Bernardo) (08/01/90)
DICUSSIONS OF THE MORALITY, NATURALNESS, ETC. OF HOMOSEXUALITY DO NOT BELONG IN SOC.MOTSS. THERE ARE OTHER GROUPS FOR THE POSTING OF ONE'S BIASES (EVEN THE ONES SHROUDED IN SCIENTIFIC SPECULATION). In article <1990Jul31.012219.3299@ariel.unm.edu> mwfolsom@hydra.unm.edu (Mike Folsom) writes: >I'm starting to wonder if homosexuality isn't a mix of genetics and >environment. This is not my area but I've always wondered about >pheromones and if they have any involvement in the whole process. ... Until you've shown that homosexuality and heterosexuality are separate phenomenon needing separate explanations, wonderings like this are a misguided consequence of your bias. By wondering as above, you're simply presuming that heterosexuality needs no explanation. These questions need to be asked of sexual orientation in general, not of just one particular sexual orientation. -- Rob Bernardo, Mt. Diablo Software Solutions "If the world were a logical place, men would ride sidesaddle." Rita Mae Brown email: rob@mtdiablo.Concord.CA.US phone: (415) 827-4301
jmast@unix.cis.pitt.edu (John M Allen) (08/02/90)
In article <1990Jul31.012219.3299@ariel.unm.edu> mwfolsom@hydra.unm.edu (Mike Folsom) writes: > >To add my two cents. I have been keeping an informal record fo MZ >lesgay twins for years. So far out of about 6 MZ twins I have found >only one who "says" that his brother is straight. > Being a gay man with an identical twin, I thought that I would add my two cents worth. I think that part of the reason that there is not total concord between the sexualities of MZ twins is that people are forgetting to take some factors into account. One of these is that the genotype allows a range of phenotypes which could account for some of the discrepencies. Another complicating factor is that orientation is not equivalent to sexual behavior. My own situation is a case in point. I have had relationships with members of both sexes, but I have a distinct preference for men. As far as I know, my brother, J, has only had one relationship and that is with his wife. All other things being equal, this could be explained by assuming that our genotype was for bisexuality and various environmental influences pushed me toward the homosexual and J toward the heterosexual end of the spectrum. I think that this would partially explain why it took me so long to come out (at the age of 24). Some additional information changes the picture. J joined the Mormon Church during our freshman year in college. A book I am reading suggests that gay men who are trying to suppress their sexuality often join fundamentalists religions because the clear demarcation between good and evil helps them to maintain the demarcation between them and their sexuality making it easier to objectify and then reject this part of them. That J once told me, "I thought I was gay for awhile, but then I found religion," indicates that this may be the case here. I think that S, J's wife, recognizes, but is unwilling to admit, the possibility that J is gay. My brother, F, who is also gay, seems to get along quite well with S, but S seems to act very cold to me. The only reason I can see for this is that I am both gay and her husband's identical twin. I think that to her I embody the worst that could happen with J. To sum up, I feel that our genotype lies on the homosexual side of the spectrum and that our phenotype allows us to function as heterosexuals and may in fact mean that J is a true bisexual. J's involvement in the Mormon church helps him to suppress any homosexual feelings that he may have. \ | | John Allen \ \ || allen@mercutio.lcl.cmu.edu / \ jmast@unix.cis.pitt.edu "Some day I'll dance among the stars and shower burning desire among the clouds, but today I dance upon the earth and feel its mud between my toes and the wind blow through my soul." ---Ry Schwark
dgil@pa.reuter.COM (Dave Gillett) (08/02/90)
I'd be really interested in any information about pheromones in humans, too, especially since I'm anosmic....
huff@agnes.acc.stolaf.edu (Charles Huff) (08/02/90)
I suggest that you refer to an excellent chapter by Roger Brown (of Harvard). It appears in his introductory social psychology text: Brown, Roger, (1986). _Social_Psychology:_The_Second_Edition._ New York: Free Press. He reviews several studies on this topic and (surprise) finds that the evidence is mixed and the topic needs more research. -Chuck
diercks@infohh.rmi.de (Peter Diercks) (08/02/90)
In his article G. S. Puterbaugh writes: "Right now, my own impression is that human sexuality is built upon a very strong genetic foundation which is probably modifiable by hormonal events within the womb." Recently I read in my newspaper an article about a (new?) book: The Mona Lisa Syndrome (this is the title in Germany), written by the British biochemist and medical Prof. Leon Kaplan (Oxford University). As I did not read this book myself, I can only summarize its principal contents after that newspaper article: Kaplan claims to have found out that homosexuality in both sexes is caused by a certain hormonal disorder in the mother's organism during certain periods of pregnancy. The main reasons for this hormonal disorder (i.e. mainly lack or excess of testosterone) seem to be stress (!!) and naturally induced oscillation of hormone levels over the year. I remember that some years ago I read about the research results of a professor for psychology at the Humboldt University in East Berlin. Unfortunately I do not remember his name. He had interviewed many (male) homosexuals and finally found out, that most of their mothers had suffered from severe stress of different kinds during pregnancy. This would fit the abovementioned results. Peter Diercks, Hamburg, W. Germany
rick@wicat.UUCP (Rick Moll) (08/02/90)
geoffp@cup.portal.com (Geoffrey Scott Puterbaugh) writes: > The concordance rate for homosexuality among male MZ (identical) >twins is the interesting number addressed by these studies. Could you define this? At first I thought it meant that if the "concordance rate" were 75% that would mean that, out of all sets of MZ twins, 3/4 would be the same (either both homo or both hetero) and 1/4 would be different (one of each). Under that definition, however, there are some other things in your article that don't make sense to me. >If the theory of environmental causation were true, then one >would expect no concordance for homosexuality at all; that >is, homosexuals would appear at the basic Kinsey rate of 5 >to 10 per cent of the male population. ... >should prove to be as high as 80 or 90 per cent, then it >would probably be enough to settle the nature/nurture If 5% of the male population is homosexual, and homosexuality is completely independent of genetics, then I get (.95*.95) + (.05*.05) = .905 or 90.5% of pairs of male twins should have the same sexual preference just by chance. Using 10% homosexual, I get 82% having matching preference just by chance. Is the study of which you speak starting with twins where one brother is known to be homosexual, and then checking whether the other one is also? In that case, 90% would indeed be startling since it would not include the large number of uninteresting hetero-hetero pairs. Also, are we speaking of twins raised apart here? How was the sample collected? I'm not a biologist, so I appologize if everyone else in this group knows what these numbers mean. --Rick Moll rick@wicat.com
geoffp@cup.portal.com (Geoffrey Scott Puterbaugh) (08/02/90)
Most of the articles in the twins/homosexuality literature begin with an "index twin" -- the author(s) discover a gay man who has a twin, and then proceed to find out whether his twin is also gay. This is not true for all of the studies. The other case -- Hm, this man is hetero, let's check out his twin! -- seems almost never to happen, except by chance (as in Heston & Shield's study of a large family with three sets of male MZ twins.) Geoff
rob@mtdiablo.Concord.CA.US (Rob Bernardo) (08/02/90)
In article <766@infohh.rmi.de> diercks@infohh.rmi.de (Peter Diercks) writes: >Kaplan claims to have found out that homosexuality in both sexes is >caused by a certain hormonal disorder in the mother's organism during >certain periods of pregnancy. What makes it a "disorder" rather than a "variation" (other than researcher's bias, that is)? -- Rob Bernardo, Mt. Diablo Software Solutions "If the world were a logical place, men would ride sidesaddle." Rita Mae Brown email: rob@mtdiablo.Concord.CA.US phone: (415) 827-4301
dab5b@mendel.acc.Virginia.EDU (David A. Baxter) (08/03/90)
In article <294@saxony.pa.reuter.COM> dgil@pa.reuter.COM (Dave Gillett) writes: >I'd be really interested in any information about pheromones in humans, too, >especially since I'm anosmic.... Well, my understanding (from a radio newsreport) is that the human pheromone research that has been conducted has indicated that humans are INSENSITIVE to these chemicals. Of course, they only checked to see if males are attracted to female pheromones (and vice versa)... Talk about an un- balanced design! :) Anyway, if there is really a general interest in the subject, send me e-mail and I can do a computer search of the relevant literature and come up with what is currently known. Dave
urjlew@uncecs.edu (Rostyk Lewyckyj) (08/05/90)
The summary says it all. :-)
joshua@athertn.Atherton.COM (Flame Bait) (08/10/90)
In article <766@infohh.rmi.de> diercks@infohh.rmi.de (Peter Diercks) writes: >Kaplan claims to have found out that homosexuality in both sexes is >caused by a certain hormonal disorder in the mother's organism during >certain periods of pregnancy. The main reasons for this hormonal disorder >(i.e. mainly lack or excess of testosterone) seem to be stress (!!) and >naturally induced oscillation of hormone levels over the year. This meshes well with some research I read about years ago, which stated that the levels of homosexuality in rats when up as their crowding increased. Joshua Levy (joshua@atherton.com)
rees-k@condor.cis.ohio-state.edu (kathryn m rees) (08/11/90)
In article <766@infohh.rmi.de> diercks@infohh.rmi.de (Peter Diercks) writes: >Kaplan claims to have found out that homosexuality in both sexes is >caused by a certain hormonal disorder in the mother's organism during ^^^^^^^^ >certain periods of pregnancy. The main reasons for this hormonal disorder ^^^^^^^^ >(i.e. mainly lack or excess of testosterone) seem to be stress (!!) and >naturally induced oscillation of hormone levels over the year. Did you choose this wording or is that how it was worded in your source? If Kaplan chose it, my problem is with him. If you chose it, may I ask why you say disorder as opposed to variation or some other word that does not imply abnormality or dysfunctional occurrance? -=- miss kate "...and you won't eat vegetables!" - my mother