The world is made up of many different kinds of things, and
in order to get around the world successfully, we have to learn both about the
individual items we encounter and we also need to learn information that will
help us to deal with new things. So,
when you learn that a particular object in your world is a chair, you need to
know what to do with it, but you also need to pick up bits of knowledge that
will be of value when you learn about other objects, like tables, lamps, or
ovens.
When you look at what adults know about the world, there is
a big difference in the way they think about artifacts and animals. Artifacts are human-made objects that are
designed for some purpose, while animals are the result of an evolutionary
process.
Generally speaking, the artifacts of a particular type vary
a lot more than animals of a type. Any
given chair might have legs, or it might have a pedestal. It may be made of many different kinds of
materials. It may have many different
colors. The fact that something is a
chair tells us a little about it (like it was made for sitting on), but not
much else.
In contrast, different animals of a type are all fairly
similar. Cats, for example, have four
legs, are furry, have similar internal organs, and behave in similar ways.
Adults recognize that animals and artifacts differ in this
way.
At what age do people learn about this difference between
animals and artifacts?
The difficulty with answering this question definitively is
that young kids often have trouble telling us what they know. As a result, it is useful to have more
indirect ways of teasing apart what they know.
A clever study by Amanda Brandone and Susan Gelman in the
January 2013 issue of Cognitive Development
examined the way kids talk about animals and artifacts as a way of assessing
what they know about these kinds of things.
In particular, they focused on generic
language. A generic statement is one
that is meant to apply to (nearly) all of the objects being described. If someone says, “Chairs are made for sitting
in,” she means this sentence to apply to (nearly) all chairs. If she says “Cats meow,” then she means to
describe (nearly) all cats. If children
know that animals generally have more in common than objects, then we would
expect children to use generic language more often when talking about animals
than when talking about objects.
In this study, five-year-olds were shown a set of drawings
of things that they were told came from an alien planet. Some children were
shown the pictures and were told that they were kinds of artifacts (like
machines, vehicles, and tools). Other
children were shown the same pictures and were told that they were alien animals. Each object was given a novel category
name. So, a child might be told that a
particular object was a “dax.” The novel
category name was used so that children could only use general knowledge about
things to understand the new object.
At the start of the study, children were introduced to a
puppet that they were told was blind.
After seeing each picture, they were asked to tell the puppet about the
object. A group of adults were shown the
same objects and were also asked to describe them.
The experimenters analyzed the language that the children
and adults used to describe the objects.
In particular, they were interested in how often children and adults
used generic statements to describe artifacts and animals.
Both the adults and the children used generic statements
more often when describing animals than when describing artifacts. That means that even pre-school children know
that animals of a particular kind have more in common with each other than
artifacts of a particular kind. When
adults and children used non-generic language, they used it about equally often
for the artifacts and the animals. So,
it is not just that people wanted to talk more about the animals than about the
artifacts.
These expectations about objects and animals guide the way children
learn about new things. Because children
expect animals of a particular type to have lots of similarities, they look for
those similarities when they encounter a new animal. When children encounter an artifact, though,
they spend more time exploring the function of the artifact than the
properties.
