Dave Munger has a post up about discernment when it comes to wine. The Munger sayeth:
Researchers have known for some time that not everyone has the same ability to detect tastes. Some people -- "super-tasters" -- are especially sensitive to a wide range of tastes. As it turns out, whether or not you're a super-taster may come down to your ability to detect a single molecule: 6-n-propylthiouracil, or PROP for short. Those who can taste PROP find it incredibly bitter, but super-tasters are also extra sensitive to saltiness, sweetness, and even tactile sensations in the mouth.
I've posted on the genetics of taste and smell. There's a lot there. As it happens, it seems that there is some variation in the distribution of supertasters across the world. South Asians have the lowest frequency in general of supertasters. Some people have hypothesized that this might be due to an adaptation to spice in food; nontasters have a higher tolerance threshold for many flavors because of their insensitivity. I'm skeptical, but it's an idea. In any case, I've reproduced some data on taste variation between populations. I've also calculated the proportion of supertasters, assuming that this is a homozygous inverse of non-tasters. The data below aggregated tasters and supertasters, but a little algebra and Hardy-Weinberg assumptions can generate the proportion of supertasters.
For the record, I'm a nontaster, and I have a crappy palette.
Population% Taster Calculated Supertaster
Brazilian Indian 9981
Pure American Indians 9457
Ecuadorian Andean 93-9557
Kenya African 9251
Mixed American Indian X Caucasian 9047
African Americans 88-9146
Ashkenazic Jews 7222
North American Caucasian 7020
Indian (South) 488