Understanding whether inbreeding accounts for early mortality is a long-standing concern in demographic research. Analyzing Bedouin villages in Bekaa, Lebanon, in which the marriage rate among first cousins is more than twice the national average, a new study appearing in the October issue of Current Anthropology finds that the greatest single determinant of infant mortality is not closely related parents – though this does present a significant risk – but short birth intervals.
The Bekka Bedouin are Sunni Muslims. Traditionally nomadic, migrating with herds of sheep and goats to pastures in the Syrian desert, they have recently become more sedentary, though a continuing preference for kin as marriage partners – particularly ibn ‘amm (father’s brother’s son) or bint ‘amm (father’s brother’s daughter) – remains “a salient feature of Bedouin matrimonial life,” writes Suzanne E. Joseph (University of Massachusetts, Dartmouth). About 47 percent of Bedouin marriages are between first cousins. Thirty-three percent are patrilateral, that is, between the children of brothers.Analyzing a sample of 1,399 Bedouin children, Joseph examined the mortality rate for infants (
As Joseph explains, the preference for choosing relatives as marriage partners may be a default marital strategy in situations where geographic isolation restricts the size of the mating pool, such as in nomadic societies. In sedentary societies, reproductive isolation may have an economic angle, preventing the fragmentation of property or facilitating unions among the poor by allowing them to circumvent dowry payments.
“While there is a heightened risk of infant mortality associated with consanguinity, even after controlling for socioeconomic and demographic factors, there are also substantial social, economic, and emotional benefits to marrying kin,” Joseph writes. “Women in particular are able to draw upon the support of their family members after marriage, which enhances their position in the domestic unit.”
Among populations with a high level of familial endogamy, there may also be a relatively high risk of recessive disorders which develop in childhood. However, the children of Bedouin first-cousin parents were not significantly more likely to die in childhood, Joseph found.
Indeed, the most statistically significant factor in a Bedouin child’s survival – whether the child of first cousins or not – is birth interval, Joseph reveals. For every additional month that passes before the birth of the next child, the odds of infant death decrease by 3.7 percent.
The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung
A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg
A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
24.01.2017 | Physics and Astronomy
24.01.2017 | Life Sciences
24.01.2017 | Health and Medicine