The size heuristic

Explanations > Decisions > The size heuristic

Description | Example | Discussion | So what

Description

The quantity heuristic is very simple: when we are deciding on the 'size' of something, we will typically look for something to tell us how big that thing is.

In doing this, we will most typically mistake 'lots' for big'. Quantity, of things or even just words, can seem like a lot.

Size can also be mistaken for quality. If there's a lot of stuff, then it must be good stuff. If one thing is good, then the rest must be good.

Example

Our family is made up of three people, two dogs, one cat, a budgerigar, a hamster and twenty-seven assorted goldfish!

When you buy this car, we'll throw in a car-care kit that includes a screen wash sachet, a bright duster, a super-sucker sponge, a special car-wax can and a pouch to put it all in.

If you took all the people in New York and stood them one on top of the others, they'd reach to the moon and back seven times.

Discussion

When we are looking to understand things, we often do so in terms of other, already familiar things. Size can be one of these things. We want to know 'how big' and use 'how many' instead, simply because that is available.

So what?

So to convince someone that something is big, chop things down into smaller parts. And vice, versa: to convince them that something is not so big, combine the parts into one big whole.

You can also use silly examples, such as putting people on top of one another, as above, to highlight size.

See also

Theories about decision errors, Availability Heuristic