Learn about how dogs’ personalities are rooted in their DNA; one skill that doesn’t get worse as you get older; and how your sense of smell works. In this podcast, Cody Gough and Ashley Hamer discuss the following stories from Curiosity.com to help you get smarter and learn something new in just a few minutes: Dogs' Personalities Are Rooted in Their DNA — https://curiosity.im/2OfDwvJ Scientists Have Identified One Skill that Doesn't Deteriorate with Age — https://curiosity.im/2LwW5tm Additional resources discussed: How does the sense of smell work? | HowStuffWorks — https://health.howstuffworks.com/mental-health/human-nature/perception/question139.htm Human Nose Can Detect a Trillion Smells | Science — https://www.sciencemag.org/news/2014/03/human-nose-can-detect-trillion-smells Download the FREE 5-star Curiosity app for Android and iOS at https://curiosity.im/podcast-app. And Amazon smart speaker users: you can listen to our podcast as part of your Amazon Alexa Flash Briefing — just click “enable” here: https://curiosity.im/podcast-flash-briefing.
Learn about how dogs’ personalities are rooted in their DNA; one skill that doesn’t get worse as you get older; and how your sense of smell works.
In this podcast, Cody Gough and Ashley Hamer discuss the following stories from Curiosity.com to help you get smarter and learn something new in just a few minutes:
Additional resources discussed:
Download the FREE 5-star Curiosity app for Android and iOS at https://curiosity.im/podcast-app. And Amazon smart speaker users: you can listen to our podcast as part of your Amazon Alexa Flash Briefing — just click “enable” here: https://curiosity.im/podcast-flash-briefing.
Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/where-dogs-get-their-personalities-how-smells-work-and-a-skill-that-improves-with-age
CODY: Hi! We’re here from curiosity-dot-com to help you get smarter in just a few minutes. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn about where dogs’ personalities come from; one skill that doesn’t get worse as you get older; and what smells are made of.
CODY: Let’s satisfy some curiosity.
Dogs' Personalities Are Rooted in Their DNA — https://curiosity.im/2OfDwvJ (Ashley)
Have you ever wondered why your golden retriever is so friendly, or why your neighbor's German shepherd is such a fierce protector? It turns out that a lot of the personality traits that differentiate dog breeds are rooted in their genes. But here’s something even cooler: humans actually change dogs' brains when they select for those behaviors that make each breed unique. Amazing, right? Okay, lemme back up for a second. A 2019 study used reports from the Canine Behavior Assessment and Research Questionnaire to identify 14 key doggie personality traits that may have a genetic basis. That questionnaire is an online survey that’s been helping pet owners assess their dogs’ behavior since 2005. And researchers compared the responses in that questionnaire to genetic data that had been gathered by other researchers. In the end, they linked genetic information to the behavioral data of around 14,000 dogs from dozens of breeds, and found 131 places in a dog's DNA that may affect those traits. The study found that the most inheritable traits included trainability, a desire for attention, and the tendency to be aggressive toward strangers. But the research also says that genetics only accounts for about 15 percent of a dog breed's personality, so perfectly behaved designer dogs are probably not in our near future — although that hasn't stopped humans from trying for thousands of years. According to another study published in September in the Journal of Neuroscience, the long history of human-applied dog breeding has actually changed the structure of dogs' brains. And that variation goes beyond brain size and shape.
Scientists generated maps of six distinct brain networks based on brain scans from 33 different dog breeds, to see where they’d find behaviors like social bonding or movement. They found that different behaviors in different breeds were correlated with variations in these neural networks, which supports the idea that there's a genetic basis for behavioral traits.
The scientists also mapped the evolutionary relationships between dog breeds and found that the most variation occurred in recent branches of the dogs' phylogenetic tree. This suggests that selection by humans to develop specific dog breeds has had a direct impact on the pooches' brains. So basically, dogs’ personalities are rooted in their DNA, but breeding choices over thousands of years has intensified the differences between dog breeds. And you thought puppy preschool had a big impact!
Scientists Have Identified One Skill that Doesn't Deteriorate with Age — https://curiosity.im/2LwW5tm (Republish) (Cody)
Good news if you’re worried about losing skills as you get older: scientists have identified one skill that doesn’t deteriorate with age. And it’s a pretty important one: as in, our ability to speak, write, and learn new vocabulary. Literary greats like Toni Morrison stand testament to this fact. Her last novel appeared when she was 84. And check this out: it seems that not only do these skills not deteriorate, exercising them may actually prevent cognitive decline.
Studies have found that some aspects of our language abilities, like knowing what words mean, actually improve during middle and late adulthood. One found that older adults living in a retirement community near Chicago had an average vocabulary size of over 21,000 words, while the vocabularies of a sample of college students included only about 16,000 words.
Our language abilities sometimes act like a canary in the cognitive coal mine: They can be a sign of future mental impairment decades before those issues manifest themselves.
In 1996, epidemiologist David Snowdon and a team of researchers studied the writing samples of nuns. They found that the grammatical complexity of essays written by the nuns when they joined their religious order could predict which sisters would develop dementia several decades later.
And keeping a journal, has been shown to substantially reduce the risk of developing various forms of dementia, including Alzheimer's disease.
Meanwhile, reading fiction has been associated with a longer lifespan. A large-scale study conducted by the Yale University School of Public Health found that people who read books for at least 30 minutes a day lived, on average, nearly two years longer than nonreaders. And a July 2019 study found that studying a foreign language in older adulthood improves overall cognitive functioning.
The moral of the story is that the writing is clearly on the wall. In order to age well, it helps to keep writing, reading, and talking.
LISTENER QUESTION
ASHLEY: We got a listener question from Vignesh who asks, “What is smell? ...It’s like, we know about light (it’s made of photons) and sound (it’s made of vibrations). Similarly I'm curious about the whats and hows of smell.” Great question Vignesh!
The simple answer is that smell is made of molecules. I mean, sure, everything is made of molecules, but when you catch a whiff of a freshly peeled orange or crinkle up your nose at the smell of old garbage, it’s because the molecules that make up that smelly thing have wafted through the air to your nose. So, yeah, every bad smell you’ve smelled? Particles of it are actually inside your nose. That’s also why, say, freshly baked bread smells stronger than day-old bread — the heat sends more of those odor molecules up into the air to reach your nose. Once there, they travel to a spot near the top of the nasal cavity that’s lined with olfactory receptor neurons. Fun fact: these receptors are the only sensory neurons in your whole body that are exposed to the outside world. The receptors sport hair-like projections called cilia that bind to a particular odor molecule, activate the receptor neuron, and lead you to perceive a smell. Scientists think that the human body has hundreds of different olfactory receptors, each of which allows us to smell a different smell. But any given smell is usually not from one kind of molecule — instead, it’s often made up of a combination of many different molecules, each of which bind to a different receptor. Scientists had long believed that we were capable of smelling about 10,000 different scents, but in 2014, a new study showed that that was a massive underestimate: instead, most people can discriminate about 1 trillion smells. I hope that answered your question, Vignesh — thanks for being nosy. If you have a question, send it in to podcast at curiosity dot com!
https://health.howstuffworks.com/mental-health/human-nature/perception/question139.htm
https://www.sciencemag.org/news/2014/03/human-nose-can-detect-trillion-smells
CODY: Before we recap what we learned today,
NEW YORK COMIC CON PLUG
CODY: Okay, so now, let’s recap what we learned today. Today we learned that dogs’ personalities are rooted in their DNA, but breeding choices over thousands of years has intensified the differences between dog breeds
ASHLEY: We also learned that your language skills actually get better as you get older. And reading and writing can help!
CODY: And that [listener question topic]
[ad lib optional]
CODY: Join us again Monday to learn something new in just a few minutes. And have a great weekend! I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Stay curious!