Comparative Cognition

Learning Objectives

By the end of this chapter, you will be able to:

• Explain the importance of studying animal cognition for understanding human psychology
• Describe the basic principles of evolutionary theory and their relevance to cognitive development
• Compare and contrast cognitive abilities across different animal species
• Evaluate evidence for theory of mind, concept formation, and numerical abilities in animals
• Analyze the debate over uniquely human cognitive abilities including language, tool use, and culture

Table of Contents

1. Why is an Understanding of Animal Cognition Important?
2. Evolution
3. Historical Study of Animal Intelligence
4. Comparative Cognition
5. Methodology for Testing Animal Cognition
6. Cognitive Abilities in Nonhuman Animals
7. Cognitive Abilities That Make Humans Unique?
8. Conclusion

Why is an Understanding of Animal Cognition Important?

Most scientists agree that all animals are related to each other due to the process of evolution. Because we share common descent with all other animals, the differences between “us” and “them” is only a matter of degree. To understand the mind of an animal is to understand ourselves. Besides, it’s really fun to talk about what animals can do! Everyone with a dog can tell you just how smart they really can be. Every week some study somewhere reveals some new aspect of animal cognition—it’s not that animals suddenly got a lot smarter, it’s that scientists are just starting to figure out how to ask the right questions.

The Simple Systems Approach

Many scientists subscribe to the simple systems approach to science. This means that scientists seek out simpler models first, so that a better understanding of the basic principles can be had before moving onto more complex systems. For psychology, the simple systems approach often includes work with animals, particularly rats, because they are simpler than humans and many more factors can be controlled.

By controlling factors like diet, housing, and weight in animal studies, scientists have a much easier time recognizing the basic principles of behavior and cognition—presumably the basic principles that all animals share. As a great example, Nobel laureate Eric Kandel and his associates have studied classical conditioning in the sea slug (Aplysia californica), a very simple creature using just three neurons, to understand what chemical changes occur at the neuronal level during learning.

Evolution

Evolutionary Theory Before Darwin

The Greek philosopher Anaximander was the first to lay out some of the ideas of biological evolution, including notions of common descent and transmutation of species. However, Anaximander also believed that the first humans developed inside of fish!

As knowledge built in biology, geology, and natural history, people began questioning the literal reading of the Book of Genesis. Due to overwhelming fossil evidence, there was little question within the 18th century scientific community that organisms had changed over time (evolved). The primary question involved the mechanism driving this change.

Biologists during the 18th century, led by Jean-Baptiste Lamarck, proposed Lamarkian Evolution or inheritance of acquired characteristics. The most famous example involves giraffes stretching to reach high leaves of the Acacia tree. According to this theory, stretching for years would strengthen and lengthen the giraffe’s neck, and these changes would be passed to offspring.

Basics of Darwinian Evolution

Survival of the Fittest

Charles Darwin was inspired by many scientists, notably Charles Lyell and Thomas Malthus. Lyell’s The Principles of Geology convinced Darwin that the world changes with time and that fossils can be dated based on their location relative to other fossils (stratification). Malthus wrote An Essay on the Principle of Population, describing how animals always produce more offspring than an environment can support. Darwin took from this the notion of the struggle for survival, which later merged with Herbert Spencer’s ideas to create “Survival of the Fittest.”

Natural Selection

Modern biologists no longer view inheritance of acquired characteristics as the mechanism for evolutionary change, but rather natural selection. Natural selection is the process whereby certain characteristics of a species are “selected” over others. Selected characteristics tend to be those that:

• Contribute to species survival
• Increase the probability an animal will mate
• Prolong individual life
• Increase odds of successful mating
• Increase care of resulting offspring

Characteristics that can be selected include physical traits, social behaviors, and cognitive abilities.

Environmental pressures drive natural selection. Traits that increase survival and reproduction likelihood in one environment may not work the same way if the environment changes. The motive behind evolutionary forces is not perfection, but survival in the current environment.

Humans have used artificial selection (selective breeding) to influence which traits are passed to the next generation in domesticated species. For example, farmers have selected for calmness in cows over thousands of years, making modern domestic cows barely identifiable with their wild ancestors.

Common Descent

The principle of common descent holds that if animals can trace back their ancestry to the same point, they share common descent. In modern biological thinking, all animals share common descent, though the time since a common ancestor varies. For example:

• Humans share a common ancestor with chimpanzees about 6 million years ago
• With lemurs about 63 million years ago
• With dogs about 85 million years ago

Since the nearest common ancestor with chimpanzees is closer in time, humans have more in common with chimpanzees than with lemurs or dogs.

Comparative anatomy studies similarities and differences between species. It’s fascinating that humans, chimpanzees, lemurs, and dogs all share the exact same organs and bones. Even the bones in bird wings or fish fins can be matched to bones in a human hand, though shaped differently for different functions.

Punctuated Evolution

Gould describes how Darwin clung to the belief of Natura non facit saltum (“nature does not make leaps”), making gradualism a critical assumption. Darwin felt evolution was orderly with slow, steady progression, but the fossil record often failed to provide crucial intermediate species.

Gould advocates for punctuated equilibrium instead of gradualism. Like Darwin, Gould argues evolution is driven by environmental pressures. As long as the environment stays relatively stable, natural selection ensures species evolve mechanisms conducive to survival. However, environmental changes tend to be rapid (ice ages, asteroid impacts), causing many organisms to die out rapidly. Only those able to survive and reproduce in the new environment pass along their characteristics.

Therefore, the fossil record should consist of long periods of stability followed by short periods of rapid change. Transitional fossils are rare not because they don’t exist, but because they existed for only a geologic blink of an eye.

Criticisms of Evolutionary Theory

Though evolutionary theory is widely accepted in the scientific community, it faces criticism:

1. Lack of intermediate species fossils – addressed by Gould’s punctuated equilibrium explanation
2. Lack of experimental evidence for speciation – Recent research has created artificial speciation in laboratory fruit flies
3. Creationism – belief that all animals were created in current form by a deity
4. Intelligent design – argues many universe features came about through intelligent cause rather than blind natural selection

Moving Beyond Biology: Sociobiology

Traditional evolutionary theory, focused on individual survival and reproduction, cannot explain much social behavior, particularly altruism (concern for others’ well-being that overrides self-concern).

Sociobiology attempts to explain all social behaviors in terms of evolutionary fitness. Within sociobiology, the primary unit of evolutionary change is not the individual organism, but the gene. The central problem: how can altruism, which reduces personal fitness, evolve by natural selection?

The answer is kinship: if genes causing altruism are shared by organisms due to common descent, and the altruistic act increases the joint contribution of these genes to the next generation, the propensity to altruism will spread through the gene pool.

Historical Study of Animal Intelligence

In the late 1800s, there was wealth of interest in animal intelligence resulting from Darwin’s later works, The Descent of Man (1871) and The Expression of Emotions in Man and Animals (1872).

George John Romanes

Comparative psychology was founded by George John Romanes (1884; 1889; 1892). Romanes felt there were cognitive similarities between humans and other animals. He made remarkable claims about animal intelligence using anecdotal evidence and anthropomorphism (attributing human characteristics to animals).

For example, he attributed jealousy to fish: “we are entitled to attribute to fish the emotions conducive to play; for nothing can well be more expressive of sportive glee than many of their movements. As for jealousy, the fights of many male fish for the possession of females constitutes evidence of emotions which would be called by this name in higher animals.”

Morgan’s Canon

Stories like Romanes’ led C. Lloyd Morgan to issue his famous warning known as Morgan’s canon: animal activity should always be explained using the simplest mechanisms possible (principle of parsimony). If an animal’s behavior could be attributed to a specific cognitive skill or to simpler stimulus-response learning, we must accept the simplest explanation.

Clever Hans

In the early 20th century, a horse in Germany named Hans became a celebrity. Hans’ trainer claimed Hans could perform mathematics, tell time, understand calendars, read, and spell. Hans would answer questions by tapping his hoof.

Psychologist Carl Stumpf formed a panel of experts who concluded no tricks were being played. The task passed to Oskar Pfungst, who discovered that Hans could only get the right answer if:

1. The questioner knew the right answer
2. The questioner was within Hans’ sight

Pfungst found that questioners unconsciously modified their posture with a slight shift when Hans had tapped the correct amount. Hans had simply learned to begin tapping and stop when seeing the questioner pull back slightly. Morgan’s canon shines again!

Behaviorism’s Influence

During much of the 20th century, behaviorism dominated psychology. Behaviorism emerged due to anecdotal evidence in comparative psychology. Behaviorism concerns external behaviors that can be measured, publicly observed, and replicated.

Strict behaviorists like Skinner felt that while not denying mental life in animals, it was not something that could be studied experimentally. However, cognitive behaviorists like Tolman and Hull proposed using intervening variables (mechanisms not directly measurable, like intelligence and emotion) to explain animal behavior.

Comparative Cognition

Comparative cognition studies the origins and mechanisms involved in cognition across various species. Like comparative anatomy, it only makes sense with the assumption of common descent.

Neuroanatomical Differences

Human and vertebrate animal brains are similar in many ways. Considering three basic brain areas:

• Hindbrain and midbrain (brainstem): Controls survival functions including breathing, heartbeat, arousal, pain, and balance
• Forebrain: Includes the limbic system responsible for motivation and emotions

Real differences between humans and other vertebrates arise when considering the cerebral cortex – the outermost brain part most responsible for higher-order cognitive processes including memory, attention, language, thought, and awareness.

True differences appear in the amount of “gray matter” – cortex parts without predetermined function that are available for truly higher-order thinking.

DNA Markers

Recent DNA advances allow previously unthinkable questions. Scientists discovered human accelerated regions (HARs) – 49 chromosome regions very similar across vertebrates but much different in humans. These highly mutated areas are thought responsible for human neuroanatomy, language, and complex thought development.

FOXP2 is the gene thought responsible for language skills development. FOXP2 gene mutations in humans link to language development disorders. Mice with only one functional FOXP2 gene display significantly fewer vocalizations than littermates.

Since the human-chimpanzee divergence, many genes have been lost to inactivation through pseudogenization – genes that served a purpose in chimpanzees have been “turned off” in humans. Examples include genes for smell, immune response, and body hair (turned off about 240,000 years ago).

Methodology for Testing Animal Cognition

Methodology for assessing animal intelligence continues using techniques established in the last century, including mazes and Skinner boxes.

Common Testing Methods

Radial-arm mazes: Often used to study animal memory. Has a central hub and eight (or more) 4-foot arms spaced equidistantly around the hub. Food sites are placed at arm ends, and researchers study an animal’s ability to remember which arms it has previously visited.

Morris water maze: A tub of murky water containing an escape platform just below the surface. When a rat is placed in water, it searches randomly at first. On subsequent trials, the rat’s memory for spatial location can be tested.

Hebb-Williams intelligence test: Created an intelligence test for animals using a modified kitchen table with 4-inch high walls and wire mesh covering. Additional walls could be added to increase maze complexity while start and goal boxes remained in the same locations.

Matching to sample: Commonly used with monkeys, an animal must choose a stimulus matching a comparison stimulus. With delayed matching to sample, the comparison object is shown, then removed with a delay added before the animal makes its selection.

Problem-Solving Tasks

One of the more interesting techniques involves setting up problems for animals to solve, since problem-solving ability is a key element of intelligence definition. Examples include:

• Testing whether crows can choose between straight and bent wires as tools
• The patterned string task with food rewards attached to string ends
• Using mirrors to study theory of mind

Cognitive Abilities in Nonhuman Animals

Important Warning: Morgan’s Canon

Throughout searching for cognitive abilities, Morgan’s canon must never be forgotten. If an animal’s behavior could be attributable to a specific cognitive skill or simpler stimulus-response learning, we must always accept the simplest explanation.

Animal cognition can only be inferred through behavior. While human cognition can also only be inferred through behavior, humans have a unique form available: verbal behavior.

Intelligence

Intelligence is a hypothetical construct often used as behavior explanation. Gottfredson (1997) reports a definition agreed to by 52 intelligence researchers:

“A very general mental capability that, among other things, involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly and learn from experience. It is not merely book learning, a narrow academic skill, or test-taking smarts. Rather, it reflects a broader and deeper capability for comprehending our surroundings—’catching on,’ ‘making sense’ of things, or ‘figuring out’ what to do.”

More simply, Gottfredson (1998) defines intelligence as the ability to deal with cognitive complexity. To make the definition inclusive for all animals, it must include the ability to adapt to environmental changes.

Assessing Animal Intelligence

Intelligence in humans and animals can only be inferred from behavior. If one rat completes a maze with fewer errors than another (controlling for experience), we might infer the first rat has more “intelligence.”

Nature vs. Nurture

The nature vs. nurture question asks whether intelligence is a matter of inborn natural abilities (nature) or environmental products (nurture). The modern answer: intelligence is a product of both, with current questions involving their relative contributions.

Heron (1935) selectively bred rats based on maze-solving ability. Within four generations, two strains emerged: maze-bright and maze-dull, producing significantly different scores. By the 11th generation, there was no overlap in scores between groups, demonstrating that some component of intelligence is heritable.

Hebb (1949) studied enriched environment effects on intelligence. Rats were reared either in laboratory cages (impoverished group) or in Hebb’s home with his daughters, allowed to roam and play (enriched group). Following several weeks, enriched group rats outperformed impoverished group rats on standard laboratory tasks.

Rosenzweig and colleagues expanded this work dramatically, showing enriched environments (exposure to toys and social interaction) create behavioral and brain differences, including increased physical weight and volume, increased synapses, and increased cerebral blood flow.

Theory of Mind

Theory of mind is the ability to attribute thoughts and feelings to oneself and others, and understand that others’ thoughts and desires differ from one’s own. This ability isn’t all-or-none—it can be exhibited in a range and is subject to development.

Young children displaying egocentrism (viewing the world exclusively from one’s own point of view) probably haven’t fully developed theory of mind. Among humans, theory of mind develops alongside language.

Arguments That Animals DO Have Theory of Mind

• Subordinate chimpanzees take advantage of what dominant chimpanzees know when choosing which food containers to approach, usually approaching food behind barriers the dominant chimpanzee cannot see
• Chimpanzees understand vision’s role in attention, producing more visible behaviors when human trainers’ eyes are open versus closed
• Competitive games show chimpanzees consistently choose opaque tubes over clear ones and silent tubes over noisy ones to conceal their movements from human players
• Similar understanding has been demonstrated in capuchin monkeys, dolphins, and dogs

Arguments That Animals Do NOT Have Theory of Mind

• Choice procedures with chimpanzees choosing between experimenters (one who had seen where food was hidden, one who was blindfolded) resulted in essentially random choices
• Auditory information studies found chimpanzees didn’t use others’ knowledge of auditory information when making selections, not being sensitive to whether competitors could hear where food was placed

Concept Formation

Concepts are mental groupings of similar objects, events, or people. They form the foundation of an animal’s cognitive structure and understanding of the world. Concepts allow animals to successfully interact with their world by enabling generalization of learning.

The more intelligent an organism, the better they are at forming concepts. More concepts increase an animal’s ability to effectively solve problems.

Object Permanence

Object permanence is the recognition that objects no longer visible still exist. This important concept allows for thinking not available without it. Object permanence doesn’t appear suddenly in humans but develops gradually, with definite evidence at six months of age.

Evidence exists for object permanence in:

• Monkeys
• Dogs and cats
• Parrots and jays

Conservation

Conservation is the concept that objects retain their mass or volume despite changes in shape. It tends to appear during toddler years. In Piaget’s classic studies, children were shown two tall beakers with equal water amounts. After the child confirmed they were the same, water from one beaker was poured into a shallow bowl. Children without conservation answer that the beaker has more water because it’s taller.

Full-fledged conservation doesn’t occur until later, developing gradually like object permanence. Three-year-olds tend to succeed on tasks requiring basic symbolic thinking for conservation.

Monkeys (rhesus macaques and capuchin monkeys) have successfully demonstrated conservation of quantity, choosing larger numbers of objects despite the amount of space they occupied. Conservation has also been demonstrated in bonobos, chimpanzees, orangutans, and squirrel monkeys.

Categorization

Humans and animals tend to create categories based on their specific environment. Studies have been performed to see if animals could understand natural and abstract categories.

Pigeons were shown pictures of objects belonging to four categories (car, cat, chair, flower) and trained to press corresponding buttons in a Skinner box. Pigeons learned to press correct buttons for initial pictures and could choose the correct button better than chance for new pictures in these categories, suggesting they truly understood these “natural” categories.

Categorization abilities have been displayed in diverse species including honeybees and monkeys.

Memory

Memory is the ability to encode, store, and retrieve information, or more specifically, memory is shown whenever evidence of prior learning is demonstrated.

In information-processing psychology, the world is filled with nearly infinite stimuli that could possibly enter the memory system. The memory system, through the sensory register, has access to every stimulus for very brief time. Due to limited attention capacity, only the most salient stimuli enter the memory system.

If we pay attention to something, it may move from the sensory register to short-term memory (working memory). George Miller (1956) reported that short-term memory has a capacity to hold 7 ± 2 items. Through chunking information into larger units or other mnemonic strategies, we can greatly increase memory capacity.

Most short-term memory information fades away, but some gets encoded into long-term memory—a nearly limitless capacity for memory storage. Eventually, many memories need to be retrieved back to working memory for use.

Animal memory seems to work essentially the same way as human memory. Although memory processes are similar, memory capacity in honeybees and voles, and memory duration in cats is limited compared to human memory. However, when memory tasks are made more relevant to animals (such as memory required for foraging or remembering where food is stored), animals perform quite well.

Numerical Skills

Animals seem to display many of the same numerical abilities as humans. From an evolutionary perspective, this shouldn’t be surprising since all animals face similar challenges needing to be solved, particularly foraging and mating. Similar mechanisms arose to meet similar challenges.

Despite amazing similarities in animals’ numerical abilities, there are major differences in degree. A rat will never solve algebraic equations, but rats don’t need algebra to find food—animals only evolve skills they need to survive.

Telling Time

Animals need to discern time and often use reliable cues like sunshine to know when a new day begins. Roosters crow when the sun comes up but can be fooled to crow in the middle of the night if an appropriate light source is presented. During solar eclipses, birds stop chirping, presumably thinking it’s nighttime.

Psychology is more interested in animals’ ability to tell time durations without external cues. Animals’ need to tell time in the wild tends to associate with foraging activities. For example, bees must remember how long since visiting a flower to assess whether enough pollen has built up to merit a revisit.

Evidence comes from studies using Fixed Interval reinforcement schedules with rats and pigeons. Animals placed on this schedule show similar responding patterns: little responding immediately following reinforcement, with response rates increasing as time passes, being maximal just before reinforcement becomes available.

The peak procedure takes advantage of this pattern. On some trials, no reinforcement is included at the critical time, and animals’ response rates are recorded. Animals’ peak response rates occur at times they normally receive food, suggesting time measurement ability.

Counting and Numerical Abilities

Counting abilities have been reported in various animal species including:

• Primates
• Lemurs
• Dogs
• Pigeons
• Salamanders and fish

This list length indicates numerical abilities were an early evolutionary arrival serving a crucial survival function. The extent of these abilities ranges from mere larger vs. smaller detection in lower animals to theoretical mathematics performance in humans.

Alex, an African Grey Parrot, was the subject of a thirty-year experiment regarding numerical and counting abilities. Alex could distinguish concepts of bigger, smaller, same, different, over, and under, and had developed an understanding of zero. However, critics argue animal numerical abilities are limited at best to crude understanding of values up to four. Many believe true number understanding emerges only with language.

Pattern Learning

Animals’ ability to detect and learn patterns would help them forage successfully. Hulse and Campbell (1975) measured running times for rats in a straight alley maze too long to see the end. Food pellet reinforcement (14, 7, 3, 1, or 0 pellets) was available at the end of each trial.

For one group, reinforcement size was chosen randomly on each trial—after several trials, running speed was fairly consistent. For another group, reinforcement size changed systematically: 14 pellets on trial 1, 7 on trial 2, 3 on trial 3, 1 on trial 4, then 0 on trial 5, then the pattern repeated.

In the patterned group, running times differed on each trial. On trials with 14, 7, or 3 pellets available, rats ran quickly, but on trials with 1 or 0 pellets available, rats ran slowly. Despite being unable to “see” the reinforcement, rats in the patterned reinforcement group could predict the available reinforcement.

Cognitive Abilities That Make Humans Unique?

Early philosophers argued that only humans have a soul, making us special. Then Darwin told us humans are just another animal, no more special than any other. We share common ancestors with other animals and many of the same cognitive abilities.

Since this revelation, psychologists and anthropologists have been searching for what makes us uniquely human and separates us from other animals. Three possible candidates for uniquely human abilities are language, tool use, and culture. However, to varying degrees, some argue each has been demonstrated in animals.

Language and Communication

Communication is the act of conveying ideas and information from one organism to another. All animals communicate somehow—dogs wag tails, cats hiss, bees use waggle dances to indicate nectar locations. Most animal communication seems limited to expressing information about concrete ideas and events occurring in the present moment.

However, many feel that despite these communication abilities, true language is reserved only for humans. Language is a symbolic communication system capable of conveying both concrete and abstract ideas. True language involves grammar use, something seemingly lacking in all animal communication.

Language allows communication of ideas about past, present, or future, as well as hypothetical possibilities. Human language can be used in socially unique ways, like transmitting jokes and riddles. Additionally, even the most advanced animal communication systems are limited to a few dozen signs, whereas human language contains thousands of signs.

However, language seems to have evolved from simpler forms of animal communication. Darwin himself suggested human language had roots in emotional communication.

When Did Language Emerge?

There’s disagreement about when humans or their ancestors first used language. Some estimate language emerged about two million years ago during Homo habilis, others believe it didn’t emerge until 40,000 years ago during Cro-Magnon man.

These estimates developed from examining often incomplete fossilized remains and extrapolating larynx appearance. Many human speech advances became possible due to descended larynx development. Very few other animals have evolved descended larynxes. A descended larynx greatly increases choking likelihood; therefore, the advantage humans gained by developing speech must have been very large.

Universal Grammar

Noam Chomsky (1965) proposed that humans are unique among animals—they have inborn universal grammar. This includes grammatical structure elements common to all languages. Chomsky believes these language elements don’t need learning; humans are born ready for language through linguistic intuitions, including:

• Recognition that the same sentence can mean different things
• Ability to recognize parts of speech (subject vs. object)
• Ability to recognize when different sentences mean the same thing

Teaching Language to Animals

In opposition to Chomsky’s assertion that language is uniquely human, many researchers have attempted to teach true language to animals.

Early attempts involved trying to teach chimpanzees to talk. A chimpanzee named Vicki was raised in a human home along with a regular child. After several years, Vicki acted like a human child in many ways, but her linguistic output was severely limited because she lacked a descended larynx, making most human sounds impossible to produce.

The Gardners noticed that while Vicki lacked actual words, she seemed to incorporate many gestures in her communication efforts. They decided teaching an animal American Sign Language would be more sensible.

The Gardners (1989) raised a chimpanzee named Washoe from infancy. Washoe learned sign language from direct teaching using reinforcement principles, but also learned some skills simply by watching the Gardners communicate. Washoe signed during formal training sessions and during play times. When older, she was given a foster infant named Loulis. Without any reinforcement, Washoe taught Loulis many signs she knew. Washoe seemed to view language as something more than a mere tool for receiving reinforcement—language was valuable in itself.

Many other monkeys have been taught language forms. Despite these success stories, critics claim true language is unique to humans because:

• For every success story, there are dozens of failures
• Though monkeys can be taught language skills, it doesn’t come naturally (unlike children who readily pick up language with no formal teaching)
• Monkeys rarely use more than two-“word” phrases, and grammatical structure is spotty at best
• In most cases, monkeys’ language use can be explained as efforts to receive reinforcement

Tool Use

Natural selection has done a good job giving animals the “tools” they need to solve problems they face. Darwin’s famous Galapagos Finches are a great example. Long ago, finches were isolated on various islands in the Galapagos Archipelago. On each island, the finch’s primary food source differs. Twelve different but closely related species of finches have evolved, each with different beak shapes (definitely tools) perfectly suited to solve the problems each finch faces.

However, natural selection forces are relatively slow, and sometimes an animal’s natural tools prove insufficient to provide all necessary food. In these cases, many animals supplement their available tools with other objects.

Examples of animal tool use:

• Otters and chimpanzees use rocks to open nuts
• Egyptian vultures use stones to crack open ostrich eggs
• Green herons use food pieces as “bait” when trying to catch fish
• Woodpecker finches use straw pieces to reach into holes and get insects

However, these examples might not qualify as true tool use because animals have simply used objects they find. Many researchers argue true tool use only occurs when an object is modified for a specific purpose.

Tool Modification

Jane Goodall’s work revealed that at least some animals modify objects for specific purposes. Chimpanzees like to eat termites. To get termites, chimpanzees will:

1. Choose a stick
2. Strip off the leaves
3. Gnaw on the stick to make it more attractive to termites
4. Poke the stick into a termite mound and “fish” for termites
5. Occasionally pull the stick out to suck off any termites

New evidence reveals chimpanzees actually use multiple tools in the process. Before fishing, they first select a thicker stick to create a decent-sized hole in the termite mound. Chimpanzees also sharpen sticks for hunting small mammals.

Though tool use in non-primates is less commonly reported, findings about tool creation from other animals are beginning to emerge. A New Caledonian crow was able to take a straight piece of wire, insert it into a crack, then use the resulting “hook” to pull a basket containing food from a tube.

Dolphins have been seen tearing off sponge pieces, which they then wrap around their snout to avoid abrasions when searching for food along the sea floor.

Culture

All around the world, humans face similar problems, but because historically populations were isolated, these populations solved problems in slightly different ways. The accumulation of these different solutions to similar problems creates culture—ways of doing things and solving problems (involving mores and customs) that are geographically local and passed from one to another within a social group.

Culture in Animals

Researchers working with Kinji Imanishi studied Japanese snow monkeys extensively during the 1950s. Researchers left sweet potatoes on the beach to view monkeys easily. After a while, one monkey named Imo took the sweet potato to the ocean and rinsed off the sand. Soon, other troop members displayed this behavior. After a few years, 80% of younger monkeys displayed the ability while only 20% of older monkeys did (“you can’t teach an old dog new tricks!”). Now, over 50 years later, the tradition has passed from generation to generation and almost all troop members wash sweet potatoes. However, snow monkeys in different troops on different islands don’t show this food washing behavior.

Culture has also been seen in orangutans as evidenced by local expression of distinct behaviors passed from generation to generation:

• Members of at least one group make sputtering noises with their mouth before going to sleep, as though saying “good night”
• Some groups use leaves as napkins when eating
• Orangutans from Sumatra get water from holes by dipping in branches, then licking off the leaves, while orangutans from Borneo don’t exhibit this behavior

Evidence for culture among non-monkey species has been less prevalent, though evidence is mounting.

Conclusion

Though humans are clearly “at the top” of the evolutionary ladder, the differences between humans and other animals in every way is merely a matter of degree. Biologically, we share features and functions with other animals. The physiology of humans and other animals seems to have developed out of a shared past which went in different directions depending on the challenges each species faced.

Because of these physiological findings, it shouldn’t be terribly surprising that human cognition and animal cognition also arose from a shared past. Just like with physiology, each species had its own unique set of challenges to face, and the cognitive mechanisms we initially shared with other animal species went in slightly different directions.

Key Terms

Altruism: A concern for the well-being of others which overrides a concern for the self.

Anthropomorphism: Attribution of human characteristics and tendencies onto nonhuman animals or objects.

Artificial Selection: Intentional breeding of animals to ensure that certain traits or combination of traits which are desirable to the breeder are passed to the next generation.

Behavioral Theory of Timing: Explanation of animals’ ability to tell time that posits that animals tell time by counting the number of behaviors that fit into a particular interval.

Brainstem: Lower two-thirds of the brain, responsible for survival functions including breathing, heartbeat, arousal, pain, and balance.

Cerebral Cortex: Outermost part of the brain that is most responsible for higher order cognitive processes including memory, attention, language, thought, and awareness.

Common Descent: If animals can trace back their ancestry to the same point, then they are said to have common descent. In modern biological thinking, all animals share common descent.

Communication: The act of conveying information from one organism to another.

Comparative Cognition: The study of the origins and mechanisms involved in cognition across various species.

Concept: Mental grouping of similar objects, events, or people.

Conservation: The concept that objects retain their mass or volume despite changes in their appearance.

Culture: Ways of doing things and solving problems (involving mores and customs) that are geographically local and passed from one to another within a social group.

Evolution: The process of change in a species across generations driven by various forces of biology and nature.

FOXP2: A gene thought to be responsible for the human development of grammatical competence and language.

Grammar: A set of rules used for the expression of a language.

Human Accelerated Regions (HARs): A set of 49 segments of the human genome that are very similar among all nonhuman vertebrates, but are very different in humans.

Inborn Universal Grammar: Elements of grammatical structure that are common to all human languages.

Intelligence: Hypothetical construct often used to explain behavior. Though the exact definition is highly debatable, includes ability to adapt to changes in the environment.

Intervening Variables: Mechanisms which are not directly observable, yet which are used to explain the relationship between variables in an experiment. Examples include intelligence and emotion.

Language: A symbolic communication system capable of conveying both concrete and abstract ideas.

Long-term Memory: Representations of knowledge and skills which are stored for long periods of time.

Memory: Ability to store, retain, and retrieve information; memory is evident whenever evidence of prior learning has been demonstrated.

Morgan’s Canon: Precept that animal activity should always be explained using the simplest mechanisms possible (principle of parsimony).

Natural Selection: Process whereby certain characteristics of a species which lead to increased probability of successful mating are “selected” over others.

Object Permanence: Concept that objects are permanent entities that do not vanish when out of sight.

Punctuated Equilibrium: A theory of evolution that argues that most species remain quite stable for most of their history with the majority of changes occurring in relatively short periods of time.

Sensory Register: A component of the memory system that registers everything available to the senses.

Short-term Memory: A set of processes for holding information in our awareness (working memory).

Simple Systems Approach: The approach to science which seeks out the simplest system possible first in order to understand the basic mechanisms which drive all systems.

Sociobiology: Attempt to explain all social behaviors in animals in terms of the evolutionary fitness of these behaviors.

Theory of Mind: Ability to attribute thoughts and feelings to oneself and others as well as ability to understand that other’s thoughts and desires are different from one’s own.

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