There’s a valid reason why Americans are so into pumpkin spice, and that reason is science.

In case you’re not aware (and honestly, by this point, we’re not sure how that could be possible), pumpkin spice is massive in America. Like, Gaytime-in-a-tub multiplied by Vegemite Cadbury big. Made famous by Starbucks, whose pumpkin spice lattes are the franchise’s best-selling seasonal drink, there’s now pumpkin spice everything – beer, yoghurt, cereal, hummus, popcorn.

So what’s so special about this simple mix of spices?

It’s science, betches.

Jordan Gaines Lewis recently broke it down for The Conversation – and it all boils down to reactance, the idea that if something is only available for a limited time, it becomes much more attractive (like a Bachelor contestant, I guess?) There’s a social aspect to this, too – everyone’s doing it, so we feel like we should, too.

Totally explains the popularity of that Vegemite chocolate, then.

Want to make your own pumpkin spice at home? Learn how to here.