about ScientificMatch

Physical chemistry is based on the immune system. When we analyze your DNA, we look exclusively at your immune system genes. So, quite literally, when we say that two people have “chemistry”, we’re saying that their immune system genes are perfectly matched with each other.

By perfectly matched, we mean different. After we analyze your DNA, we match you with other people who have different immune system genes from yourself.

The theory is that nature wants us to breed with other people who have different immune systems because it creates babies with a wider variety of immune system genes, and therefore, more robust immune systems—in other words, healthier babies. [Doherty & Zinkernagel, 1975; Dyall et al, 2000; Mitton 1993 & 1997; Penn et al, 2002] It also discourages inbreeding and the associated health consequences [Dobzhansky, 1937; Potts et al, 1994; Apanius et al, 1997; Grob et al, 1998; Penn and Potts, 1999; Penn, 2002], and it enables us as a species to adapt to changing diseases and disease environments. [Bodmer, 1972; Burnet, 1973; Wakeland et al, 1990]

Since nature’s goal is to perpetuate the species, it encourages us to mate with others who have immune systems different from our own.

For example, you’ve probably noticed that you’re not sexually attracted to your brother, sister, mother, or father. That’s because they’re all part of your immediate gene pool, and you all probably have very similar immune systems. Nature doesn’t want you to mate with them, because the health of your baby, and the longevity of our species, would suffer.

You may have experienced the power of chemistry in another way: Perhaps you know someone who looks just like “your type”, but somehow you just don’t feel that “sexual spark” when you’re together. They seem more like a brother or sister than a potential lover. It could be that you have too much in common—namely, your immune system genes.

Conversely, maybe you’ve found yourself talking to someone who you distinctly did NOT consider to be your type, and yet with whom you distinctly DID feel a sexual spark. Again, your immune system genes could be at the source.

 

Sources Cited:

Apanius, V, Dustin J Penn, P Slev, LR Ruff, & Wayne K Potts (1997) “The Nature of Selection on the Major Histocompatibility Complex,” Critical Reviews in Immunology, vol 17, pp 179-224.

Bodmer, WF (1972) “Evolutionary Significance of the HL-A System,” Nature, vol 237, pp 139-183.

Burnet, FM (1973) “Multiple Polymorphism in Relation to Histocompatibility Antigens,” Nature, 245, 359–361.

Dobzhansky, Theodosius (1937) Genetics and the Origin of Species 1st edition, Columbia University Press, New York.

Doherty, Peter C, & Rolf M Zinkernagel (1975) “Enhanced Immunological Surveillance in Mice Heterozygous at the H-2 Gene Complex,” Nature, vol 256, pp 50-52.

Dyall, Ruben, Ilhem Messaoudi, Sylvia Janetzki, & Janko Nikolic-Zugic (2000) “MHC Polymorphism Can Enrich the T Cell Repertoire of the Species by Shifts in Intrathymic Selection,” The Journal of Immunology, vol 164, pp 1695-1698.

Grob, B, LA Knapp, RD Martin, & G Anzenberger (1998) “The Major Histocompatibility Complex and Mate Choice: Inbreeding Avoidance and Selection of Good Genes,” Experimental and Clinical Immunogenetics, vol 15, no 3, pp 119-129.

Mitton, Jeffry B (1993) “Theory and Data Pertinent to the Relationship Between Heterozygosity and Fitness,” The Natural History of Inbreeding and Outbreeding: Theoretical and Empirical Perspectives (ed Thornhill, NW), pp 17-35, University of Chicago Press, Chicago Press, Chicago.

Mitton, Jeffry B (1997) “Selection in Natural Populations,” Oxford University Press, Oxford, UK.
Penn, Dustin J, & Wayne K Potts (1999) “The Evolution of Mating Preferences and Major Histocompatibility Complex Genes,” The American Naturalist, vol 153, no 2, pp 145-164.

Penn, Dustin J, & Wayne K Potts (1999) "The Evolution of Mating Preferences and Major Histocompatibility Complex Genes," The American Naturalist, vol 153, no 2, pp 145-164.

 

Penn, Dustin J (2002) “The Scent of Genetic Compatibility: Sexual Selection and the Major Histocompatibility Complex,” Ethology, vol 108, pp 1-21.

Penn, Dustin J, Kristy Damjanovich, & Wayne K Potts (2002) “MHC Heterozygosity Confers a Selective Advantage Against Multiple-Strain Infections,” Proceedings of the National Academy of Sciences of the United States of America, vol 99, no 17, pp 11260-11264.

Potts, Wayne K, C Jo Manning, Edward K Wakeland, & AL Hughes (1994) “The Role of Infectious Disease, Inbreeding and Mating Preferences in Maintaining MHC Genetic Diversity: An Experimental Test,” Proceedings of the Royal Society of London, Series B, vol 346, no 1317, pp 369-378.

Wakeland, Edward K, Stefen Boehme, & Jin Xiong She (1990) “The Generation and Maintenance of MHC Class II Gene Polymorphism in Rodents,” Immunological Reviews, vol 113, pp 207-226.