Stephanie N. Del Tufo, University of Delaware

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to CuriousKidsUS@theconversation.com.

“Do we need to read, or can we just get everything through audio, like podcasts and audiobooks?” – Sebastian L., 15, Skanderborg, Denmark

Let’s start with a thought experiment: Close your eyes and imagine what the future might look like in a few hundred years.

Are people intergalactic travelers zooming between galaxies? Maybe we live on spaceships, underwater worlds or planets with purple skies.

Now, picture your bedroom as a teenager of the future. There’s probably a glowing screen on the wall. And when you look out the window, maybe you see Saturn’s rings, Neptune’s blue glow or the wonders of the ocean floor.

Now ask yourself: Is there a book in the room?

Open your eyes. Chances are, there’s a book nearby. Maybe it’s on your nightstand or shoved under your bed. Some people have only one; others have many.

You’ll still find books today, even in a world filled with podcasts. Why is that? If we can listen to almost anything, why does reading still matter?

As a language scientist, I study how biological factors and social experiences shape language. My work explores how the brain processes spoken and written language, using tools like MRI and EEG.

Whether reading a book or listening to a recording, the goal is the same: understanding. But these activities aren’t exactly alike. Each supports comprehension in different ways. Listening doesn’t provide all the benefits of reading, and reading doesn’t offer everything listening does. Both are important, but they are not interchangeable.

Different brain processes

Your brain uses some of the same language and cognitive systems for both reading and listening, but it also performs different functions depending on how you’re taking in the information.

When you read, your brain is working hard behind the scenes. It recognizes the shapes of letters, matches them to speech sounds, connects those sounds to meaning, then links those meanings across words, sentences and even whole books. The text uses visual structure such as punctuation marks, paragraph breaks or bolded words to guide understanding. You can go at your own speed.

Listening, on the other hand, requires your brain to work at the pace of the speaker. Because spoken language is fleeting, listeners must rely on cognitive processes, including memory to hold onto what they just heard.

Speech is also a continuous stream, not neatly separated words. When someone speaks, the sounds blend together in a process called coarticulation. This requires the listener’s brain to quickly identify word boundaries and connect sounds to meanings. Beyond identifying the words themselves, the listener’s brain must also pay attention to tone, speaker identity and context to understand the speaker’s meaning.

‘Easier’ is relative – and contextual

Many people assume that listening is easier than reading, but this is not usually the case. Research shows that listening can be harder than reading, especially when the material is complex or unfamiliar.

Listening and reading comprehension are more similar for simple narratives, like fictional stories, than for nonfiction books or essays that explain facts, ideas or how things work. My research shows that genre affects how you read. In fact, different kinds of texts rely on specialized brain networks. Fictional stories engage regions of the brain involved in social understanding and storytelling. Nonfiction texts, on the other hand, rely on a brain network that helps with strategic thinking and goal-directed attention.

Reading difficult material tends to be easier than listening from a practical standpoint, as well. Reading lets you move around within the text easily, rereading particular sections if you’re struggling to understand, or underlining important points to revisit later. A listener who is having trouble following a particular point must pause and rewind, which is less precise than scanning a page and can interrupt the flow of listening, impeding understanding.

Even so, for some people, like those with developmental dyslexia, listening may be easier. Individuals with developmental dyslexia often struggle to apply their knowledge of written language to correctly pronounce written words, a process known as decoding. Listening allows the brain to extract meaning without the difficult process of decoding.

Engaging with the material

One last thing to consider is engagement. In this context, engagement refers to being mentally present, actively focusing, processing information and connecting ideas to what you already know.

People often listen while doing other things, like exercising, cooking or browsing the internet – activities that would be hard to do while reading. When researchers asked college students to either read or listen to a podcast on their own time, students who read the material performed significantly better on a quiz than those who listened. Many of the students who listened reported multitasking, such as clicking around on their computers while the podcast played. This is particularly important, as paying attention appears to be more important for listening comprehension than reading comprehension.

So, yes, reading still matters, even when listening is an option. Each activity offers something different, and they are not interchangeable.

The best way to learn is not by treating books and audio recordings as the same, but by knowing how each works and using both to better understand the world.

Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age and the city where you live.

And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.

Stephanie N. Del Tufo, Assistant Professor of Education & Human Development, University of Delaware

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Leslie Root, University of Colorado Boulder; Karen Benjamin Guzzo, University of North Carolina at Chapel Hill, and Shelley Clark, McGill University

Pronatalism – the belief that low birth rates are a problem that must be reversed – is having a moment in the U.S.

As birth rates decline in the U.S. and throughout the world, voices from Silicon Valley to the White House are raising concerns about what they say could be the calamitous effects of steep population decline on the economy. The Trump administration has said it is seeking ideas on how to encourage Americans to have more children as the U.S. experiences its lowest total fertility rate in history, down about 25% since 2007.

As demographers who study fertility, family behaviors and childbearing intentions, we can say with certainty that population decline is not imminent, inevitable or necessarily catastrophic.

The population collapse narrative hinges on three key misunderstandings. First, it misrepresents what standard fertility measures tell us about childbearing and makes unrealistic assumptions that fertility rates will follow predictable patterns far into the future. Second, it overstates the impact of low birth rates on future population growth and size. Third, it ignores the role of economic policies and labor market shifts in assessing the impacts of low birth rates.

Fertility fluctuations

Demographers generally gauge births in a population with a measure called the total fertility rate. The total fertility rate for a given year is an estimate of the average number of children that women would have in their lifetime if they experienced current birth rates throughout their childbearing years.

Fertility rates are not fixed – in fact, they have changed considerably over the past century. In the U.S., the total fertility rate rose from about 2 births per woman in the 1930s to a high of 3.7 births per woman around 1960. The rate then dipped below 2 births per woman in the late 1970s and 1980s before returning to 2 births in the 1990s and early 2000s.

Since the Great Recession that lasted from late 2007 until mid-2009, the U.S. total fertility rate has declined almost every year, with the exception of very small post-COVID-19 pandemic increases in 2021 and 2022. In 2024, it hit a record low, falling to 1.6. This drop is primarily driven by declines in births to people in their teens and early 20s – births that are often unintended.

But while the total fertility rate offers a snapshot of the fertility landscape, it is not a perfect indicator of how many children a woman will eventually have if fertility patterns are in flux – for example, if people are delaying having children.

Picture a 20-year-old woman today, in 2025. The total fertility rate assumes she will have the same birth rate as today’s 40-year-olds when she reaches 40. That’s not likely to be the case, because birth rates 20 years from now for 40-year-olds will almost certainly be higher than they are today, as more births occur at older ages and more people are able to overcome infertility through medically assisted reproduction.

A more nuanced picture of childbearing

These problems with the total fertility rate are why demographers also measure how many total births women have had by the end of their reproductive years. In contrast to the total fertility rate, the average number of children ever born to women ages 40 to 44 has remained fairly stable over time, hovering around two.

Americans continue to express favorable views toward childbearing. Ideal family size remains at two or more children, and 9 in 10 adults either have, or would like to have, children. However, many Americans are unable to reach their childbearing goals. This seems to be related to the high cost of raising children and growing uncertainty about the future.

In other words, it doesn’t seem to be the case that birth rates are low because people are uninterested in having children; rather, it’s because they don’t feel it’s feasible for them to become parents or to have as many children as they would like.

The challenge of predicting future population size

Standard demographic projections do not support the idea that population size is set to shrink dramatically.

One billion people lived on Earth 250 years ago. Today there are over 8 billion, and by 2100 the United Nations predicts there will be over 10 billion. That’s 2 billion more, not fewer, people in the foreseeable future. Admittedly, that projection is plus or minus 4 billion. But this range highlights another key point: Population projections get more uncertain the further into the future they extend.

Predicting the population level five years from now is far more reliable than 50 years from now – and beyond 100 years, forget about it. Most population scientists avoid making such long-term projections, for the simple reason that they are usually wrong. That’s because fertility and mortality rates change over time in unpredictable ways.

The U.S. population size is also not declining. Currently, despite fertility below the replacement level of 2.1 children per woman, there are still more births than deaths. The U.S. population is expected to grow by 22.6 million by 2050 and by 27.5 million by 2100, with immigration playing an important role.

Will low fertility cause an economic crisis?

A common rationale for concern about low fertility is that it leads to a host of economic and labor market problems. Specifically, pronatalists argue that there will be too few workers to sustain the economy and too many older people for those workers to support. However, that is not necessarily true – and even if it were, increasing birth rates wouldn’t fix the problem.

As fertility rates fall, the age structure of the population shifts. But a higher proportion of older adults does not necessarily mean the proportion of workers to nonworkers falls.

For one thing, the proportion of children under age 18 in the population also declines, so the number of working-age adults – usually defined as ages 18 to 64 – often changes relatively little. And as older adults stay healthier and more active, a growing number of them are contributing to the economy. Labor force participation among Americans ages 65 to 74 increased from 21.4% in 2003 to 26.9% in 2023 — and is expected to increase to 30.4% by 2033. Modest changes in the average age of retirement or in how Social Security is funded would further reduce strains on support programs for older adults.

What’s more, pronatalists’ core argument that a higher birth rate would increase the size of the labor force overlooks some short-term consequences. More babies means more dependents, at least until those children become old enough to enter the labor force. Children not only require expensive services such as education, but also reduce labor force participation, particularly for women. As fertility rates have fallen, women’s labor force participation rates have risen dramatically – from 34% in 1950 to 58% in 2024. Pronatalist policies that discourage women’s employment are at odds with concerns about a diminishing number of workers.

Research shows that economic policies and labor market conditions, not demographic age structures, play the most important role in determining economic growth in advanced economies. And with rapidly changing technologies like automation and artificial intelligence, it is unclear what demand there will be for workers in the future. Moreover, immigration is a powerful – and immediate – tool for addressing labor market needs and concerns over the proportion of workers.

Overall, there’s no evidence for Elon Musk’s assertion that “humanity is dying.” While the changes in population structure that accompany low birth rates are real, in our view the impact of these changes has been dramatically overstated. Strong investments in education and sensible economic policies can help countries successfully adapt to a new demographic reality.

Leslie Root, Assistant Professor of Research, Institute of Behavioral Science, University of Colorado Boulder; Karen Benjamin Guzzo, Professor of Sociology and Director of the Carolina Population Center, University of North Carolina at Chapel Hill, and Shelley Clark, Professor of Sociology, McGill University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Lisa Cuchara, Quinnipiac University

On hot summer days, few things are more refreshing than a dip in the pool. But have you ever wondered if the pool is as clean as that crystal blue water appears?

As an immunologist and infectious disease specialist, I study how germs spread in public spaces and how to prevent the spread. I even teach a course called “The Infections of Leisure” where we explore the risks tied to recreational activities and discuss precautions, while also taking care not to turn students into germophobes.

Swimming, especially in public pools and water parks, comes with its own unique set of risks — from minor skin irritations to gastrointestinal infections. But swimming also has a plethora of physical, social and mental health benefits. With some knowledge and a little vigilance, you can enjoy the water without worrying about what might be lurking beneath the surface.

The reality of pool germs

Summer news headlines and social media posts often spotlight the “ick-factor” of communal swimming spaces. These concerns do have some merit.

The good news is that chlorine, which is widely used in pools, is effective at killing many pathogens. The not-so-good news is that chlorine does not work instantly – and it doesn’t kill everything.

Every summer, the Centers for Disease Control and Prevention issues alerts about swimming-related outbreaks of illness caused by exposure to germs in public pools and water parks. A 2023 CDC report tracked over 200 pool-associated outbreaks from 2015 to 2019 across the U.S., affecting more than 3,600 people. These outbreaks included skin infections, respiratory issues, ear infections and gastrointestinal distress. Many of the outcomes from such infections are mild, but some can be serious.

Germs and disinfectants

Even in a pool that’s properly treated with chlorine, some pathogens can linger for minutes to days. One of the most common culprits is Cryptosporidium, a microscopic germ that causes watery diarrhea. This single-celled parasite has a tough outer shell that allows it to survive in chlorine-treated water for up to 10 days. It spreads when fecal matter — often from someone with diarrhea — enters the water and is swallowed by another swimmer. Even a tiny amount, invisible to the eye, can infect dozens of people.

Another common germ is Pseudomonas aeruginosa, a bacterium that causes hot tub rash and swimmer’s ear. Viruses like norovirus and adenovirus can also linger in pool water and cause illness.

Swimmers introduce a range of bodily residues to the water, including sweat, urine, oils and skin cells. These substances, especially sweat and urine, interact with chlorine to form chemical byproducts called chloramines that may pose health risks.

These byproducts are responsible for that strong chlorine smell. A clean pool should actually lack a strong chlorine odor, as well as any other smells, of course. It is a common myth that a strong chlorine smell is a good sign of a clean pool. In fact, it may actually be a red flag that means the opposite – that the water is contaminated and should perhaps be avoided.

How to play it safe at a public pool

Most pool-related risks can be reduced with simple precautions by both the pool staff and swimmers. And while most pool-related illnesses won’t kill you, no one wants to spend their vacation or a week of beautiful summer days in the bathroom.

These 10 tips can help you avoid germs at the pool:

• Shower before swimming. Rinsing off for at least one minute removes most dirt and oils on the body that reduce chlorine’s effectiveness.

• Avoid the pool if you’re sick, especially if you have diarrhea or an open wound. Germs can spread quickly in water.

• Try to keep water out of your mouth to minimize the risk of ingesting germs.

• Don’t swim if you have diarrhea to help prevent the spread of germs.

• If diagnosed with cryptosporidiosis, often called “crypto,” wait two weeks after diarrhea stops before returning to the pool.

• Take frequent bathroom breaks. For children and adults alike, regular bathroom breaks help prevent accidents in the pool.

• Check diapers hourly and change them away from the pool to prevent fecal contamination.

• Dry your ears thoroughly after swimming to help prevent swimmer’s ear.

• Don’t swim with an open wound – or at least make sure it’s completely covered with a waterproof bandage to protect both you and others.

• Shower after swimming to remove germs from your skin.

Lisa Cuchara, Professor of Biomedical Sciences, Quinnipiac University

This article is republished from The Conversation under a Creative Commons license. Read the original article.