Twice Bitten, Once Shy: Confessions of a Fake Psychic Detective #5

Chapter 10

The Monty Hall(way) Problem

Ivy and Jade guide the attendees down to the lounge for post-dinner drinks. Zandra lingers while Curd Queen crew clear the dinner service. She strolls to the railing and lights up.

"Plenty of apples left if you want one. They'll keep the doctor away," a crew member says from behind Zandra. He wheels a cart with fruit gathered from the edible centerpieces.

Zandra shakes her head.

The crew member shrugs and wheels on by.

Zandra coughs into her sleeve and tries to ignore what dislodges into the purple fabric. She's been ignoring it since her trip to the hospital. Now is a good time for a distraction.

Apples, eh?

Say the word "fruit" and what's the first thing that comes to mind? Chances are very good it's an apple, at least around here. Maybe a banana.

What about "vegetable?" Chances are you thought of a carrot. A tomato might be a close second, but technically that's fruit. Not that anyone sincerely gives a shit about that other than to sound smart.

Zandra peeks at the stain on her sleeve, then stops.

The mind runs on shortcuts. It allows a person to get through a day without overthinking. Concepts associate with symbols out of both convenience and necessity. It's quicker to think of a carrot than every single vegetable. The carrot is a placeholder, like X in algebra.

These shortcuts come with a cost. They make you vulnerable to fallacies. And if you know the right fallacy to use at the right time, you can leverage that shortcut to your advantage.

That brings us to counterintuitive statistics.

Zandra calls out to the crew member with the apples. He comes back, rolling the cart along.

"Change your mind?" he says.

"No, but I wanted to ask you about weather, child," Zandra says.

"Yeah, go for it."

"I'm planning a trip after this event is over," Zandra says, lying but doing a good job at selling the lie, as usual. "The place I'm going, there is a 25 percent chance of rain each day. I'll be there for four days. Tell me, child, should I pack an umbrella? You see, I don't have an umbrella, and I'll need to buy one right away if it's going to rain at all on my trip. I don't want to be stuck indoors."

Like the cart with the apples, the crew member rolls with the question. He says, "Twenty-five percent? Nah, I wouldn't worry about it. There's a 75 percent chance it won't rain."

Zandra forces a smile and nods. "Thank you. I just wanted to talk it through with someone."

"No problem. You sure you don't want an apple?" the crew member says.

He's really pushing these apples hard.

"Thanks, but no thanks. I've got my own," Zandra says and raises her cigarette.

The crew member wishes Zandra a good evening and leaves. Zandra listens to the creak of the cart and drags on the cigarette.

He's no idiot. He's just a regular person doing what regular people do. And he's wrong about the umbrella.

Here's how not to be a regular person: know that a 25 percent chance of rain spread out over four days means it will rain on one of the four days. It's a weighted average.

In her mind, Zandra re-enacts the matching birthdays during the cold reading. She recalls how Jade said the odds of two people having the same birthday were, "One in 365."