Halloween as it is celebrated today takes its roots from the ancient Celtic festival of Samhain, which means “summer’s end” in modern Irish. Dating back to the Neolithic period 6000 years ago, this celebration traditionally marked halfway between the northern hemisphere’s autumn equinox – the date when the length of daylight and darkness is roughly the same – and the winter solstice, the day with the fewest hours of light. This usually fell around 31 October. On this day, the Celts believed that the boundary between the living and the dead was thinnest, allowing the spirits of the departed to visit the living. To scare off these rogue spirits, they would light bonfires and wear costumes made of animal skins and heads.

Today you’re as likely to find Halloween revellers dressed up as movie stars and cartoon characters as ghastly ghouls and goblins. But our curious fascination with horror, fright and the boundary between life and death seems to grow each year – not to mention our interest in increasingly sophisticated haunted houses and elaborate pumpkin carving techniques.

Unmask the hidden science of Halloween with the premium articles below, and discover why humans love horror, what drives our belief of an afterlife, the rotten mysteries of the corpse flower and much more. Mwahahaha.

Why almost everyone believes in an afterlife – even atheists

Most people hold curiously similar ideas about life after death, suggesting there is more to it than religion, fear or an inability to imagine not existing

Scientists studied a ‘haunted house’ to understand why we love horror

To understand why many of us enjoy being scared, a team of scientists studied the people visiting a haunted house set in a dilapidated factory

Why the line between life and death is now more blurred than ever

Brains resurrected after death, communications with people in comas and advances in cryogenics all suggest that life's end is less final than we thought

The surprising evolutionary history of pumpkins and squashes

Shops are stocking up on pumpkins for Halloween. While I haven't always been a fan of squashes, I've been charmed by how such unlikely fruits came to spread worldwide, says Penny Sarchet

Nightmare Fuel review: The psychology that underpins horror films

Scary movies really get under our skin, but why is this the case and how do film-makers know what will scare us? A new book has some interesting answers

Ball lightning is so strange it might just come from another dimension

Mysterious floating orbs of light have puzzled scientists for centuries, inspiring no end of creative explanations. A new idea suggests they aren't entirely of this world

The strange plant that just might be the worst smell on the planet

Corpse flowers rarely bloom but if one does when you’re nearby you’ll know about it. Though many botanical gardens have their own corpse flowers, the plant's mysteries still abound