Genetics
See also: Major histocompatibility complex and sexual selection and Body odor and subconscious human sexual attractionBody odor is largely influenced by major histocompatibility complex (MHC) molecules. These are genetically determined and play an important role in immunity of the organism. The vomeronasal organ contains cells sensitive to MHC molecules in a genotype-specific way.
Experiments on animals and volunteers have shown that potential sexual partners tend to be perceived more attractive if their MHC composition is substantially different. Married couples are more different regarding MHC genes than would be expected by chance. This behavior pattern promotes variability of the immune system of individuals in the population, thus making the population more robust against new diseases. Another reason may be to prevent inbreeding.
East Asians (Koreans, Chinese, and Japanese) have fewer apocrine sweat glands compared to people of other descent, and the lack of these glands make East Asians less prone to body odor. The reduction in body odor and sweating may be due to adaptation to colder climates by their ancient Northeast Asian ancestors. Axillary odor is known to be determined by the ABCC11 gene that also codes the type of earwax one has. Most of the population secrete "wet" earwax, however, East Asians are genetically predisposed for the allele that codes the "dry" type earwax, associated with a reduction in axillary odor. A study by Martin et al. (2010) has shown that the non-functional ABCC11 allele—predominant amongst the East Asians (80–95%)—affects apocrine sweat glands by reducing production and secretion of odorant compounds commonly found in the perspiration of other ancestral groups.
Read more about this topic: Body Odor