New scientist dating service
By having singles send in saliva samples, the site facilitates a laboratory analysis of each person's immune system type and, using this data, claims to create optimized “physical chemistry” or "sexual chemistry" between people based on the sweaty T-shirt study, a pattern, discovered in 1995, which finds that people are most attracted to the smell of people who have the most-dissimilar immune system.
 The site was conceived by Holzle, a long-time internet site dater, after watching a TV discussion on the findings of the sweaty T-shirt study.
A firsthand report from the front lines of an unprecedented social experiment.) The Atlantic Monthly, March.
Gasner states that he calculated this ratio via the ‘obvious math: (1/10)x(1/10)x(1/10) leading to the conclusion that 1 in 1,000 females was a marriage-level match’.
Those 30 million people have generated billions of pieces of data.
And because most dating sites ask users to give consent for their data to be used for research purposes, this online courting has played out like an enormous social science experiment, recording people's moment-by-moment interactions and judgments.
When you’re online dating, why do you swipe left on one person and swipe right on another?
In the mid 1970s, MHC-dissimilar tendency matching was shown to be the case for mice (and later for other animals such as fish) and in 1995 Swiss biologist Claus Wedekind, creator of the sweat T-shirt study, proved that the pattern holds for humans.
 In this study, Wedekind had a group of female college students smell T-shirts that had been worn by male students for three nights, without deodorant, cologne or scented soaps.
Overwhelmingly, the women preferred the odors of men with the most dissimilar MHCs to their own (see: adjacent video).
I like the idea of research and measurement around these things that seem so impossible to quantify."  Wall Street Journal editor Emily Parker, who interviewed Waldorf, reasoned to herself “of course, this only leads one to wonder, how does one measure interpersonal chemistry?
” She found that, “while e Harmony is launching an ambitious research project to do just that, Mr.
 In 2008, was the fourth largest online dating site, based on number of singles available; largely due to a successful ad campaign targeting e Harmony (#5 largest dating site) and their anti-gay Christian-only, who regect people who aren't happy all the time (adjacent video).