How did Halloween get associated with the spooky? SolStock/Collection E+ via Getty Images

Halloween’s celebration of mingling with the dead has roots in ancient Celtic celebrations of Samhain

Tok Thompson, USC Dornsife College of Letters, Arts and Sciences

A folklorist explains how Halloween continues an ancient Celtic tradition of the celebration of the dead.

Clowns in American circuses were once considered a form of adult entertainment. ArtMarie/E+ via Getty Images

The creepy clown emerged from the crass and bawdy circuses of the 19th century

Madeline Steiner, University of South Carolina

Today’s creepy clowns are not a divergence from tradition, but a return to it.

Kindergarten students in 1952 race out of school in Los Angeles, eager to celebrate Halloween. Los Angeles Examiner/USC Libraries/Corbis via Getty Images

How was Halloween invented? Once a Celtic pagan tradition, the holiday has evolved to let kids and adults try on new identities

Linus Owens, Middlebury

From its origins as a Celtic pagan ceremony to its celebration of all things gruesome and ghoulish today, Halloween has been reinvented over the centuries.

How to keep your jack-o’-lantern from turning into moldy, maggoty mush before Halloween

Matt Kasson, West Virginia University

Don’t let microbes and insects turn your Halloween masterpiece into a horror show before the big night.

Rainbow fentanyl – the newest Halloween scare

Joel Best, University of Delaware

Like clockwork, September crime news is often cast as an ominous sign of what could happen on Halloween.

How do you spot a witch? This notorious 15th-century book gave instructions – and helped execute thousands of women

Melissa Chim, General Theological Seminary

Witch trials relied on a medieval text called the “Malleus Maleficarum” – a book this reference librarian can hold in her hands.

Why is it fun to be frightened?

Margee Kerr, University of Pittsburgh

Visiting a haunted house or watching a horror movie can be terrifying and enjoyable at the same time. A sociologist explains the psychological benefits of being safely scared.

Day of the Dead: From Aztec goddess worship to modern Mexican celebration

Kirby Farah, USC Dornsife College of Letters, Arts and Sciences

It may sound like a solemn affair, but the Day of the Dead – which blends indigenous and Catholic ritual – is a convivial celebration that allows Mexicans to reconnect with deceased loved ones.

Kids are probably more strategic about swapping Halloween candy and other stuff than you might think

Margaret Echelbarger, University of Chicago

When deciding whether others should make trades, children may consider who likes what.

Why has Halloween become so popular among adults?

Linus Owens, Middlebury

The holiday used to be all about trick-or-treating in the neighborhood. No more – and it could something to do with the fact that traditional markers of adulthood have changed.

More ‘disease’ than ‘Dracula’ – how the vampire myth was born

Stanley Stepanic, University of Virginia

The past century’s vampires have often been a bit dashing, even romantic. That’s not how the myth started out.