Parth Shah

We just can't let go of some decisions. We replay them in our head and imagine alternate endings.

These sorts of looping mental videos are called counterfactuals. Northwestern University Professor Neal Roese says there's real value to wondering "if only."

"Counterfactual thoughts are generally useful for us in terms of providing a set of options that we might act upon in the future," he says. "This can lead to improvement. It can lead to learning from experience."

Many people start exploring their sexuality in college. The lessons they learn about intimacy and attraction during these years lay a foundation for the rest of their lives.

"I have students who have had sex many times drunk but have never held someone's hand," says Occidental University sociologist Lisa Wade.

After a disaster happens, we want to know, could something have been done to avoid it? Did anyone see this coming?

Many times, the answer is yes. There was a person — or many people — who spotted a looming crisis and tried to warn those in power. So why didn't the warnings lead to action?

After you read this sentence, pause for a moment to think back on advertisements you first heard when you were a child.

Perhaps you recall a favorite jingle or the catchphrase of a cereal mascot. You probably can remember more than just one.

This week, we look at the shelf life of commercials. According to University of Arizona researcher Merrie Brucks, an ad we watched when we were five years old can influence our buying behavior when we're 50.

Annie Duke was about to win $2 million.

It was 2004, and she was at the final hand of the World Series of Poker Tournament of Champions. Annie had beaten some of the best poker players in the world — all men — to get to this point.

But she wasn't sure she deserved to be there.

"I'm sort of thinking, if I fold and I'm wrong, everybody's going to be like, 'See, she plays like a girl, look how he pushed her around,' " said Annie.

Paul Rozin has been studying the psychology and culture of food for more than 40 years. And he's come to appreciate that food fills many of our needs, but hunger is just one.

"Food is not just nutrition that goes in your mouth or even pleasant sensations that go with it," he says. "It connects to your whole life, and it's really a very important part of performing your culture and experiencing your culture."

Bababababa, dadadadada, ahgagaga. Got that?

Babies are speaking to us all the time, but most of us have no clue what they're saying. To us non-babies, it all sounds like charming, mysterious, gobbledegook. To researchers, though, babbling is knowable, predictable, and best of all, teachable. This week, we'll find out how to decipher the vocabulary, and the behavior, of the newest members of the human family.

Have you ever noticed that when something important is missing in your life, your brain can only seem to focus on that missing thing?

After you read this sentence, pause for a moment to think back on advertisements you first heard when you were a child.

Perhaps you recall a favorite jingle or the catchphrase of a cereal mascot. You probably can remember more than just one.

On this week's Hidden Brain radio show, we look at the shelf life of commercials. According to University of Arizona researcher Merrie Brucks, an ad we watched when we were five years old can influence our buying behavior when we're fifty.

It's 3 a.m. You wake up abruptly with a bad case of dry mouth. You drag yourself out of bed and begin fumbling in the dark to get a glass of water.

You flip on the light switch, and there it is — a brown flash. A cockroach skitters across the counter.

Did reading this disgust you?

It may seem instinctive to recoil in horror after seeing a roach in your kitchen. But psychologist Rachel Herz argues that it's not.

Voting ballots for the upcoming 2018 midterm elections will feature a record number of female candidates. Despite the influx of women interested in political office, men still dominate most leadership roles in the United States.

The U.S. Embassy in Havana will continue to operate with minimal staff and will become what is known as an unaccompanied post, with an indefinite ban on family members of embassy employees residing there, the State Department says.

NPR's Michele Kelemen reports that this status typically applies only to war zones or other dangerous cities.

Secretary of State Rex Tillerson temporarily pulled all nonessential State Department staff out of Cuba in September 2017 after numerous diplomats reported experiencing strange medical symptoms, ranging from dizziness to hearing loss.

Spoiler alerts are sacred.

We plunge our fingers into our ears when a friend divulges details about a TV series we have yet to finish. We avoid articles that discuss important plot points of a movie we haven't gotten around to watching.

Sometimes, this 'no spoilers' mentality leaks in other parts of our lives. We avoid getting an important medical test done, fearing bad results. We turn off the news when the headlines make us upset, even though the information is pertinent to us. According to economist Joshua Tasoff, this behavior is irrational.

In its 152-year history, Gallaudet University in Washington, D.C. never had a deaf female president — until a year ago. Roberta Cordano is the first deaf woman to lead the school.

Gallaudet is a liberal arts university devoted to deaf and hard-of-hearing students. Classes are taught in American Sign Language, and all students and faculty are required to know how to sign.

But president Cordano never attended a deaf school herself.

The Department of Labor has guidelines for companies that want to keep unpaid interns. Essentially, unpaid interns have to be treated like students and shouldn't do the work of paid employees.

Those rules, however, don't apply to government agencies.

Oshun Afrique is getting her 35th tattoo.

She has come to the Pinz-N-Needlez tattoo shop in Washington, D.C., where practically every inch of wall space is covered in artwork. While Afrique lounges on the sofa at the front of the small, quaint shop, owner Christopher Mensah sits at his desk and sketches her tattoo design.

Afrique came to the store after seeing Mensah's work in her Facebook news feed. She and Mensah both agree that anyone looking to get tattooed should scour online portfolios to find the right artist.

When the National Museum of African American History and Culture opened in September, Associate Director Beverly Morgan-Welch expected a lot of visitors.

But she didn't expect how long people would stay once they got in. Museum experts call that "dwell time."

"The normal dwell time for most museums is an hour 45 minutes to two hours," says Morgan-Welch. "Our dwell time can go to six."

There's an etiquette to holiday decorations.

The jack-o-lantern should be tossed in the compost on November 1st and the Christmas tree ornaments need to stay in the attic until Thanksgiving dinner is over.

And in my family, there's another holiday tradition to consider: On Diwali, we put out swastikas.

Moshe the cat lives in an old brick house in the Bloomingdale neighborhood of Washington, D.C. His owner, Cassandra Slack, moved in a little more than a year ago.

The first floor feels open and airy. Large windows bring a flood of light inside, making the original hardwood floors shine.

But downstairs, in the basement where Slack lives, the atmosphere is different. The floor is carpeted, the lights are dim, and the ceiling is low.

Slack had an eerie experience down here when she first moved in.