Richard Shotton

So even though they've seen the same facts, because in this second group there was an additional reason thrown in, it reduced, it diluted the believability in that core reason.

So there's a psychological as well as practical benefit about communicating that you do one thing well.

People have a rule of thumb in their head that you can't be a jack of all trades.

If you are, you'll be a master of none of them.

So there's a sacrifice in credibility and believability if you claim to do multiple things.

I think a lot of these biases that behavioral scientists identify, that psychologists identify, they're generally true.

I mean, all things being equal,

you tend to get better at a task if it is the sole focus of your attention.

If you spend 40 hours a week being a cyclist, you're going to be a better cyclist than if I spent 10 hours a week.

So people have a sensible rule of thumb in their head, but then the danger is they over-apply it in situations where it's not relevant.

Like in the situation Zhang set up, people got the same facts about cardiovascular health,

But because they threw in this second benefit, it seemed to detract from it.

So I think it's often the misapplication of a generally sensible rule of thumb.

Yeah, that's a fair summary.

It's essentially the argument that be very, very careful about adding extra reasons to believe because what they will gradually do is undermine believability in the core reason to buy your product.

So if you start saying you're all things to all people, over time, gradually, insidiously, that original reason to buy gradually disappears.

Drill bits, sell nine-inch holes.

So I think there's an argument there.

But the other bit that struck me when you're talking about things like productivity and focus is that an awful lot of experimentation shows that people are pretty bad at remembering abstract data.

They're very good at remembering concrete physical things.