But the raters predicted the donor's level of extroversion and neuroticism through smell about as accurately as participants in a different study predicted personality traits based on a video depicting a person's behavior, Sorokowska said. Judgments of dominance were most accurate in the case where an individual rater was assessing the odor of someone who was the opposite sex, suggesting such judgments are especially important when it comes to choosing a mate, the researchers said.

— Another "smell this sweaty t-shirt" study. Read more at Some Personality Traits Affect How You Smell at Live Science. Hat tip to Erin!

Millions of receptors in the nose's smelling organ aren't scattered at random, a new study says. Instead, the receptors congregate in tiny hot spots that help the brain discern good smells from bad ones, among other potential functions.

— Read more at Secrets of Smell: Different Nose Parts for Stinky, Sweet at National Geographic.

Jess Porter and colleagues at the University of California, Berkeley, have also been trying to train people's noses. They persuaded 32 students to wear blindfolds and ear defenders, and get down on all fours to see whether they could sniff out a trail of chocolate oil. Intrigued, I wanted to try it for myself, which is how I ended up on all fours in a London park.

— From The unsung sense: How smell rules your life in the New Scientist. Hat tip to Abyss!

You might think that identical twins have an advantage when it comes to crime—with the same DNA, who could tell them apart? But new research with a squad of scent-trained Czech police dogs reveals that even identical twins have their own individual smells, even if they live in the same house and eat the same food.

— Read more at Police Dogs Can Tell Identical Twins Apart By Scent at Discover magazine.

If you like your big human brain, you can thank your nose — or at least the noses of your earliest mammal cousins.

That’s because 200 million years ago, a keen sense of smell drove an explosive growth in brain size that pushed mammals out from under the shadow of dinosaurs, a new study concludes.

— Read more at Mammals win by a nose: Sense of smell drove evolution of big brains at the Washington Post. Many thanks to nozknoz for the link!

World-class "noses" in the perfume and wine business are not born with an outsized sense of smell but acquire it through years of professional sniffing, according to new research.

In experiments with novice and veteran perfume makers, French scientists found that the ability to detect and identify hundreds, even thousands, of different odours depends almost entirely on rigorous training.

— Read more at Super sense of smell not innate at Yahoo News.

Mainstream researchers have long attributed our sense of smell to a "lock and key" hypothesis. The idea is that every odor molecule that enters our nose has a specific shape that fits a specific receptor—like a key fits a lock—allowing us to detect, say, the acrid aroma of burnt coffee. But the hypothesis leaves some questions unanswered. For one, it doesn't explain, why we can detect tens of thousands of odors with only a few hundred smell receptors. It also doesn't explain why odor molecules with very similar shapes give us such different smells; the molecules that gives us the smell of vodka and rotten eggs are almost identical, for example.

Enter vibrations. Chemists have long known that atoms in a molecule vibrate at a particular frequency, depending on their overall molecular structure. Even molecules that differ by a single atom can vibrate quite differently. In the new study, neurobiologists Maribel Franco and Efthimios Skoulakis at the Alexander Fleming institute in Athens and biophysicist Luca Turin and colleagues at the Massachusetts Institute of Technology tested whether these vibrations could account for our wide range of smell.

— From Do Vibrating Molecules Give Us Our Sense of Smell? at Science magazine. You can also find articles at New Scientist and Nature. Thanks to Tania and everyone else who passed along one or more of the links!

I recently heard an interview with Bonnie Blodgett (shown above right), who wrote a memoir about the experience of losing and rediscovering the sense of smell. I am intrigued, and have placed this book at the top of my reading list.

If you, too, have read or are planning to read Remembering Smell, let’s chat about it. How about an October book club…

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Whether it is the whiff of a woman’s perfume that takes your mind back to an ex-girlfriend, or a song that defines a moment in your life, the strong connection between senses and memory has long intrigued scientists.

However, a study has found that when we smell or hear something during an emotional experience, the odour or sound is woven together with the memory in the same region of the brain.

— From Smells linked to memories 'because they are stored in same part of brain' at the Telegraph. Many thanks to Ruth for the link!