Immunology of Sexuality and Variations

Alan J. Robinson robin073 at maroon.tc.umn.edu
Thu Jan 25 17:08:53 EST 1996


On Tue, 23 Jan 1996 14:35:00 -0700, 
Teresa Binstock   <binstoct at essex.UCHSC.edu> wrote:

>
>      IMMUNOLOGICAL COMPONENTS TO HUMAN SEXUALITY AND VARIATIONS
>

Teresa:

There are many sex-related differences in humans in areas such as 
olfaction, brain structure, and susceptibility to disease.  I assume 
that you have looked at the book "The Scent of Eros" by James Vaughn 
Kohl and Robert T Francoeur.

Even though some of these differences have been known since the time 
of the Ancient Greeks, they are still rather poorly understood.  
However, this is changing rapidly with the explosion of knowledge 
about the brain and the immune system. I don't know though of any 
single review article which fully synthesizes this knowledge in the 
area of sex-related differences in the immune system.

The increased understanding of the brain and the immune system has led 
to the realization that the body has an integrated set of defense and 
repair mechanisms (infection, trauma, neoplasia, psychological 
stress etc.), which can themselves malfunction and cause disease, as 
in the case of autoimmune disorders.  Many of these disorders are much 
more common in women.

As far as the influence of olfaction on human body function, the 
general trend of evolution has been to progressively downplay 
olfaction and increase visual capabilities.  (Some insects have 
extraordinary olfactory capabilites.)  Thus even though menstrual 
cycles can be synchronized in humans, presumably by olfaction, this is 
more likely to be an evolutionary vestige and not critical to human 
functioning.  The primary residual function of olfaction in humans 
appears to be to warn of bacterial putrefaction.

Similarly, olfaction does not appear to play a large role in human 
sexual desire (male-oriented pornography is almost entirely visual).  
The fact that humans stand upright, so their noses aren't at the same 
level as the genitals, makes them quite different from most other 
animals - dogs, for example.

There are major aspects of immune function and dysfunction which 
appear to be markedly different in males and females.  This probably 
has more to do with the close coupling of the physiological axes 
that are involved with reproduction (e.g. LHRH-LH) with the HPA axis 
and the autonomic nervous system than with specific patterns of 
antigens arising from X and Y chromosomes.  The immune system in 
females must also be designed not to reject the immunologically 
different sperm and fetus, by a mechanism which is still not 
understood.

There is considerable speculation that homosexuality arises from a 
developmental variation in the fetal brain that is the result of 
maternal (and or fetal) hormonal and immunological dysregulation.  
But it is still just speculation. 

A good review of some of these recent scientific developments is in 
the 1994 book "Brain Control of Responses to Trauma", edited by Nancy 
Rothwell and Frank Berkenbosch.  It covers more than its title 
implies.  More generally, this material is covered under such names as 
neurimmunology, psychoneuroimmunology, neuroimmunomodulation, and 
psychoneuroendocrinology.  

The independent scholar, Marjie Profet, has also published some 
interesting speculations on human sexuality and the immune 
system in the Quarterly Review of Biology.  (I'm writing this from 
memory - I'm not sure I got those names exactly correct.)

AJR




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