Percentage of Crows Correct Responses in 8 Sessions of Identical-Matching Tasks. Columns are grouped by bird (Crow 1, Crow 2) and, within each bird, by object dimension (Size, Shape, Color). Adapted from Anna Smirnova et al., “Crows Spontaneously Exhibit Analogical Reasoning,” © 2015 by Elsevier Ltd.
| Object Dimension | Crow 1 Size | Crow 1 Shape | Crow 1 Color | Crow 2 Size | Crow 2 Shape | Crow 2 Color |
|---|---|---|---|---|---|---|
| Session 1 | 77.8 | 75.0 | 66.7 | 75.0 | 63.9 | 77.8 |
| Session 2 | 75.0 | 80.6 | 80.6 | 72.2 | 63.9 | 72.2 |
| Session 3 | 86.1 | 61.1 | 86.1 | 72.2 | 63.9 | 72.2 |
| Session 4 | 86.1 | 69.4 | 75.0 | 66.7 | 75.0 | 80.6 |
| Session 5 | 72.2 | 80.6 | 69.4 | 86.1 | 83.3 | 86.1 |
| Session 6 | 80.6 | 69.4 | 75.0 | 72.2 | 66.7 | 83.3 |
| Session 7 | 77.8 | 63.9 | 63.9 | 86.1 | 75.0 | 77.8 |
| Session 8 | 80.6 | 66.7 | 91.7 | 80.6 | 77.8 | 80.6 |
| <strong>Sessions 1-8 (averaged)</strong> | <strong>79.5</strong> | <strong>70.8</strong> | <strong>76.0</strong> | <strong>76.4</strong> | <strong>71.2</strong> | <strong>78.8</strong> |
This passage is excerpted from Leyra Castro and Ed Wasserman, “Crows Understand Analogies,” © 2015 by Scientific American.
A recent research collaboration has discovered that crows
exhibit strong behavioral signs of analogical reasoning—the
ability to solve puzzles like “bird is to air as fish is to what?”
Analogical reasoning is considered to be the pinnacle of
cognition and it only develops in humans between the ages of
three and four.
Why might crows be promising animals to study? Of
course, crows are reputed to be clever. Aesop’s famous fable
“The Crow and the Pitcher” tells of a crow solving a
challenging problem: the thirsty crow drops pebbles into a
pitcher with water near the bottom, thereby raising the fluid
level high enough to permit the bird to drink. Such tales are
charming and provocative, but science cannot rely on them.
Recent scientific research sought to corroborate this fable. It
found that crows given a similar problem dropped stones into a
tube containing water, but not into a tube containing sand.
Crows also chose to drop solid rather than hollow objects into
the water tube. It thus seems that crows do indeed understand
basic cause-effect relations.
But, what happens when crows are given problems that
require more abstract thinking? Before setting our sights on
analogical reasoning, we might begin with a simpler abstract
task. For example, sameness and differentness are key abstract
ideas, because two or more items of any kind—coins, cups,
caps, or cars—can be the same as or different from one
another. Because sameness and differentness can be detected
visually, perhaps that may provide an elegant way to study
their apprehension by nonverbal animals.
To do so, we present visual stimuli on a touchscreen
monitor. We reward animals with food for contacting one
button when sets contain identical items and we reward
animals for contacting a second button when sets contain non-
identical items. Several species of birds and mammals learn
this task and also transfer their learning to new stimuli,
showing that they have learned an abstract concept, which
extends beyond the training items.
Devising a task to study analogical thinking in animals is
the next step. Here, the gist of analogy can be captured by
arranging a matching task in which the relevant logical
arguments are presented in the form of visual stimuli. Using
letters of the alphabet for explanatory purposes, choosing test
pair BB would be correct if the sample pair were AA, whereas
choosing test pair EF would be correct if the sample pair were
CD. Stated logically, A:A as B:B (same = same) and C:D as
E:F (different = different). Critically, no items in the correct test
pair physically match any of the items in the sample pair;
so, only the analogical relation of sameness can be used to
solve the task.
Now, we have found that crows too can exhibit analogical
thinking. Ed Wasserman, one of the authors of this article, and
his colleagues in Moscow, Anna Smirnova, Zoya Zorina, and
Tanya Obozova, first trained hooded crows on several tasks in
which they had to match items that were the same as one
another. The crows were presented with a tray containing three
cups. The middle cup was covered by a card picturing a color,
a shape, or a number of items. The other two side cups were
also covered by cards—one the same as and one different from
the middle card. The cup under the matching card contained
food, but the cup under the nonmatching card was empty.
Crows quickly learned to choose the matching card and to do
so more quickly from one task to the next.
Then, the critical test was given. Each card now pictured a
pair of items. The middle card would display pairs AA or CD,
and the two side cards would display pair BB and pair EF. The
relation between one pair of items must be appreciated and
then applied to a new pair of items to generate the correct
answer: the BB card in the case of AA or the EF card in the
case of CD. For instance, if the middle card displayed a circle
and a cross, then the correct choice would be the side card
containing a square and a triangle rather than the side card
containing two squares.
Not only could the crows correctly perform this task, but
they did so spontaneously, from the very first presentations,
without ever being trained to do so.
It seems that initial training to match identical items enabled
the crows to grasp a broadly applicable concept of sameness
that could apply to the novel two-item analogy task. Such
robust and uninstructed behavior represents the most
convincing evidence yet of analogical reasoning in a non-
primate animal.
A recent research collaboration has discovered that crows
exhibit strong behavioral signs of analogical reasoning—the
ability to solve puzzles like “bird is to air as fish is to what?”
Analogical reasoning is considered to be the pinnacle of
cognition and it only develops in humans between the ages of
three and four.
Why might crows be promising animals to study? Of
course, crows are reputed to be clever. Aesop’s famous fable
“The Crow and the Pitcher” tells of a crow solving a
challenging problem: the thirsty crow drops pebbles into a
pitcher with water near the bottom, thereby raising the fluid
level high enough to permit the bird to drink. Such tales are
charming and provocative, but science cannot rely on them.
Recent scientific research sought to corroborate this fable. It
found that crows given a similar problem dropped stones into a
tube containing water, but not into a tube containing sand.
Crows also chose to drop solid rather than hollow objects into
the water tube. It thus seems that crows do indeed understand
basic cause-effect relations.
But, what happens when crows are given problems that
require more abstract thinking? Before setting our sights on
analogical reasoning, we might begin with a simpler abstract
task. For example, sameness and differentness are key abstract
ideas, because two or more items of any kind—coins, cups,
caps, or cars—can be the same as or different from one
another. Because sameness and differentness can be detected
visually, perhaps that may provide an elegant way to study
their apprehension by nonverbal animals.
To do so, we present visual stimuli on a touchscreen
monitor. We reward animals with food for contacting one
button when sets contain identical items and we reward
animals for contacting a second button when sets contain non-
identical items. Several species of birds and mammals learn
this task and also transfer their learning to new stimuli,
showing that they have learned an abstract concept, which
extends beyond the training items.
Devising a task to study analogical thinking in animals is
the next step. Here, the gist of analogy can be captured by
arranging a matching task in which the relevant logical
arguments are presented in the form of visual stimuli. Using
letters of the alphabet for explanatory purposes, choosing test
pair BB would be correct if the sample pair were AA, whereas
choosing test pair EF would be correct if the sample pair were
CD. Stated logically, A:A as B:B (same = same) and C:D as
E:F (different = different). Critically, no items in the correct test
pair physically match any of the items in the sample pair;
so, only the analogical relation of sameness can be used to
solve the task.
Now, we have found that crows too can exhibit analogical
thinking. Ed Wasserman, one of the authors of this article, and
his colleagues in Moscow, Anna Smirnova, Zoya Zorina, and
Tanya Obozova, first trained hooded crows on several tasks in
which they had to match items that were the same as one
another. The crows were presented with a tray containing three
cups. The middle cup was covered by a card picturing a color,
a shape, or a number of items. The other two side cups were
also covered by cards—one the same as and one different from
the middle card. The cup under the matching card contained
food, but the cup under the nonmatching card was empty.
Crows quickly learned to choose the matching card and to do
so more quickly from one task to the next.
Then, the critical test was given. Each card now pictured a
pair of items. The middle card would display pairs AA or CD,
and the two side cards would display pair BB and pair EF. The
relation between one pair of items must be appreciated and
then applied to a new pair of items to generate the correct
answer: the BB card in the case of AA or the EF card in the
case of CD. For instance, if the middle card displayed a circle
and a cross, then the correct choice would be the side card
containing a square and a triangle rather than the side card
containing two squares.
Not only could the crows correctly perform this task, but
they did so spontaneously, from the very first presentations,
without ever being trained to do so.
It seems that initial training to match identical items enabled
the crows to grasp a broadly applicable concept of sameness
that could apply to the novel two-item analogy task. Such
robust and uninstructed behavior represents the most
convincing evidence yet of analogical reasoning in a non-
primate animal.