Quo vadis homine? Or Where the marriage goes?

Rajko rigic at EXCITE.COM
Tue Feb 10 13:09:26 EST 2015

I would appreciate it, if you comment this topic.

R. Igic

 [PDF] Quo vadis homine? Or where the marriage goes?

Page 1. Page 200 VOJNOSANITETSKI PREGLED Vojnosanit Pregl 2015; 72(2): 200–202.

PERSONAL OPI NI ON UDC: 314.5:392.543 
DOI: 10.2298/VSP1502200I 
Quo vadis homine? Or where the marriage goes? 
Quo vadis homine? Ili: Kuda ide brak? 

Rajko Igić
Department of Anesthesiology and Pain Management John Stroger Hospital of Cook 
County, Chicago, USA, and Department of Clinical Pharmacology, Medical Faculty, 
University of Banja Luka, Banja Luka, Republic of Srpska, Bosnia and Herzegovina 

Individuals are consanguineous if they are descended 
from a common ancestor no more remote than a great, great 
grandparent. The progeny of consanguineous parents are re- 
garded as inbred. Within a particular society, the population 
structure and social customs determine the frequency of con- 
sanguineous mating; certain marriage requirements as set 
forth by the church and/or state, are designed to prevent very 
close mating. 

Inbreeding of domestic animals can preserve and fix 
desirable properties and eliminate unfavorable characteristics 
from livestock. Closely related animals may be mated to 
produce pure breeds of animals and select offspring of spe- 
cific desirable types. However, because homozygote is less 
fit than heterozygote, inbreeding over a long period risks the 
loss of vigor in the offspring. Similarly, plants are inbred for 
improved characteristics, either by self-pollination or cross- 
ing with closely related plants. 

The situation in humans is far more complex. Genetic 
effects of inbreeding can be detected in the inbreed individ- 
ual, in the form of gene doubling. Affected genes appear as a 
single line in each of the common ancestors but double in the 
progeny. In other words, modern genetic technology allows 
us to show how consanguinity reveals recessive inheritance 
and recessive traits. 

One means of reducing the accumulation of undesirable 
or potentially dangerous genetic material in human popula- 
tion is to prevent conception. Same sex marriage, legalized 
in some countries, does not produce children and is thus ex- 
empt from consanguinity restrictions. If same sex marriage 
became universally legal, mating among close cousins, or 
even brothers or sisters, uncle and nephew, and aunt and 
nice. A same sex marriage without the possibility of concep- 
tion is the most efficient way to control reproduction, but this 
idea is not universally accepted. In the first place, only a 
small percentage of the population would likely be affected, 
since the heterosexual population is much larger than a ho- 
mosexual one. Secondly, and more importantly, many people 
consider a homosexual relationship to be an unnatural, even 
evil. It thus becomes increasingly difficult to predict in 
which direction marriage will go. 

Each nation or state has its own requirements for what 
constitutes a valid marriage. These marriage laws form a 
contract that allows two persons to live together as husband 
and wife. Most marriage laws apply some restrictions, in- 
cluding a statement that cousins or closer relatives may not 
marry among themselves. 

Every society considers incest as a taboo. An accumu- 
lation of recessive traits, including morality, in the progeny 
of consanguineous mate undermines and weakens society 
and can impose long lasting social and medical problems. In 
almost all societies mating between parent and offspring, 
brother and sister, and among first cousins is considered to 
be incestuous, and steps were often taken to prevent it. For 
example, The Dušan’s Code (1349) required priests to de- 
termine if bride and groom were closely related, and mar- 
riages between persons more closely related than fourth 
cousins were prohibited (Figure 1). According to the Byzan- 
tine customs of the time, a widowed daughter-in-law was 
considered by her father-in-law to be his own blood kin. 
Families of three or four generations of South Slavs (“zad- 
ruga”) lived together under similar marriage and sexual re- 
strictions, and punishment for breaking the rules was se- 
vere 1. 

Nowadays, unions between parent and child or brother 
and sister, where 50% of the genome is shared, frequently re- 
sult in abnormal offspring. As a result, these incestuous un- 
ions are considered illegal in most societies. An exception is 
that marriages between uncle and niece or aunt and nephew 
may be permitted in Southern India 2 and some isolated lo- 
cations. The closeness of this particular relationship is de- 
termined by Napoleonic Code (NC) III to have an Inbreeding
Coefficient F (IC) 1/8. The inbreeding coefficient F presents 
the probability that an individual receives two identical genes 
at the same locus. 

Marriages between cousins are the most common types 
of consanguineous mating. They are covered as follow: First 
cousin marriage (NC IV, IC 1/16), second cousin marriage 
(NC VI, IC 1/64); and third cousin marriage (NC VIII, IC 
1/256). In some societies marriage between cousins was ac- 
ceptable, as in the Nineteenth Century England when Charles 
Darwin married his first cousin, Emma Wedgwood 3. Among 
first cousin unions, where 1 : 8 genes are shared, the risk of 
abnormal offspring is 3–5%, as compared to a risk of about 
2% for a non-consanguineous union 4. For marriages be- 
tween less closely related cousins, the risks seem little if any 
increased over those for the non-consanguineous population. 
There is little reason to discourage marriages between less 
closely related couples, unless they belong to highly inbreed 
groups where heterozygosis for deleterious genes is often 
greatly increased. Restrictions of third and fourth cousin 
marriage appear to be based mainly on social and moral 

Full siblings have both parents in common, and half 
siblings share only one parent.  Marriages of first cousin and 
first half cousins belong to NC VI and IC 1/32, and those 
between second cousin and second half cousin belong to NC 
VII and IC 1/128. In the Middle East today first cousin mar- 
riage occurs at a frequency of around 11 to 68%. Due to spe- 
cific social, traditional and religious factors, consanguinity in 
Saudi Arabia is very high, with first cousin marriages at ap- 
proximately 30 percent 5. Overall consanguinity in a human 
population is expressed by an inbreeding coefficient  (  = 
p1Fi; pi is the relative frequency of inbred individuals with 
inbreeding coefficient Fi) 6. The highest inbreeding coeffi- 
cient is 0.032 in the Andra-Pradesh (India), due to preferen- 
tial uncle-niece mating. High values of inbreeding coeffi- 
cients also occur in some other isolated populations, but not 
in Polar Eskimos, where a careful avoidance of inbreeding 
keeps this value low (< 0.003). For uncle-niece, aunt- 
nephew, first cousins, second cousins marriages in human 
populations round the globe (from Argentina and the USA to 
France, Italy, and India and Japan) the average inbreeding 
coefficient is generally about 0.001 or 1 per 1000 6. Marriage 
in the USA and in many other countries, is prohibited “be- 
tween an ancestor and or descendant; or between a brother 
and a sister; between an uncle and a niece; or between an 
aunt and a nephew, whether the relationship is through half 
or whole blood or adoption” 7. 

In most civilized countries, consanguinity is the main, 
but not the only reason for the restrictions against marriage 
between close relatives. Social, moral, and religious factors 
influence an acceptable degree of consanguinity in many 
parts of the world. 

In contrast to the heterosexual marriage of man and a 
woman, same sex marriage does not produce children, thus 
eliminating the dangers of inbreeding. Same sex marriage 
could become legal among close cousins, brothers, sisters, 
uncle-nephew, and aunt-nice provided that the social, moral, 
and religious restraints would permit. If Marcus Tallius 
Cicero were alive, he would certainly shout: O tempora! O 

Despite current technologies for birth control, the total 
population of the Earth continues to increase. From time to 
time, man and nature reduce population growth through wars 
and various disasters, but such measures are insufficient. 
Wars, famine, and infective or parasitic diseases that spread 
among poor and uneducated people are disastrous means of 
controlling the population explosion. 

Perhaps marriage without the possibility of conception, 
e.g., same sex marriage, could be an additional way to con- 
trol reproduction. Indeed, some global strategists might push 
for the existing Marriage Laws to be changed accordingly. 
The question remains as to how well such a solution would 
be accepted. As of today, many individuals still consider 
homosexual unions as unnatural. It is thus unclear where this 
trend in marriage may go. 

Rather than seek such a limited solution to our bur- 
geoning population problem, we should better make efforts 
towards global peace, spread education to every human be- 
ing, reduce inequality, and provide social and economic jus- 
tice. Let us again read Dante Alighieri 8, the greatest poet of 
the Middle Ages, who suggests in Il Convivio (The Banquet) 
that the greatest danger to mankind comes from avarice. 
Wealth is not equally distributed, and the craving for it is the 
greatest danger to humanity. He believed he had the solution 
to avoiding war, but his idea unfortunately did not influence 
the rulers who prefer to solve problems militarily. We do 
hope that before long strong and creative persons will come 
up with a modern formula to find the best way for solution of 
rapidly increasing population problem—the sooner the bet- 

Financial disclosure 
No potential conflict of interest was reported. 

Fig. 1 – Mating at the level of the third cousins. According The 
Dušan’s Code, consanguinous matings were considered 
between uncle and nice, aunt and nephew, first cousins, second 
cousins, and third cousins, including «full» and «half» siblings 
in the chain of descent. Full siblings have both parents in 
common; half siblings have one parent in common. 
 = male,  = female,  = an individual of either sex.

1. Levin E. Sex and society in the world of the Orthodox Slavs 
900 1700. Ithaca: Cornell Univesity Press; 1995. 
2. Sanghvi LD. Inbreeding in India. Eugen Quart 1966; 13(4): 
291 301. 
3. Bittles AH, Mason WM, Greene J, Rao NR. Reproductive beha- 
vior and health in consanguineous marriages. Science 1991; 
252(5007): 789 94. 
4. Berkow R, Fletcher AJ. Merck Manual of diagnosis and therapy. 
15th ed. Rahway: Merck Sharp & Dohme Research Laborato- 
ries; 1987. 
5. Warsy AS, Al-Jaser MH, Albdass A, Al-Daihan S, Alanazi M. Is 
consanguinity prevalence decreasing in Saudis? A study in two 
generations. Afr Health Sci 2014; 14(2): 314 21. 
6. Cavalli-Sforza LL. Bodmer WF. The genetics of human populati- 
ons. Mineola, NY: Dover Publications; 1999. 
7. Available from: www.vdh.state.va.us/vital_records/marry.htm 
8. Igi  R. Could Chekhovian Humanism Help Us Today? J BUON 
2005; 10(1): 145 8. 

Received on December 3, 2014. 
 Accepted on December 4, 2014

More information about the SIGMETRICS mailing list