Comparative Psychology: Definition, Examples & Key Terms

Comparative psychology examples and definition, explained below

Comparative psychology is the branch of psychology concerned with the study of human and animal behavior and mental processes. It places a specific emphasis on identifying common patterns between animals and humans that can be reveal the evolutionary influences on our behaviors.

Driven by a mix of research from behavioral biology, evolutionary trends, and cognition, it looks for similarities and differences in cognitive-behavioral aspects among humans and various species of animals (Gomez, 2022).

Comparative psychology is valuable inasmuch as it provides insights into human behavior and mental processes by exploring the evolutionary realities that shape these behaviors.

History of Comparative Psychology

The phrase comparative psychology was first used in 1861 (Flourens, 1861). Soon after, the field of comparative psychology began in earnest, propelled significantly by “On the Origin of Species” by Charles Darwin in 1859.

Darwin’s groundbreaking work introduced the concept of natural selection, which sparked a newfound interest in the scientific community to understand the evolutionary underpinnings of behavior.

In turn, this led to the inception of comparative psychology as a distinct branch of psychology (Saugstad, 2018).

George Romanes, for example, subsequently argued that animals possess a “rudimentary human mind”.

Behaviorism’s Influence:

At the turn of the 20th century, classical conditioning and operant conditioning began to become central theories in psychology. Ivan Pavlov began to demonstrate how his dog could learn to associate bells with food, and that shortly also translated to human learning theories.

Similarly, John B. Watson emerged as a leading figure in the history of psychology, as well as in this field. Watson, who was a significant contributor to the development of behaviorism, emphasized the need for psychologists to focus on observable behaviors rather than internal mental states.

Watson’s seminal work revolves heavily around the idea of learning processes and their similarities in different animals, laying much of the groundwork for later research in comparative psychology (Watson, 2021). Watson, for example, taught a pigeon to play the piano!

Similarly, Harry F. Harlow studied maternal deprivation in rhesus monkeys, demonstrating how they have strong similarities with human infants.

Contemporary Progress:

As the field evolved through the 20th century, researchers slowly started to integrate more sophisticated methodologies and theoretical frameworks. They applied a spectrum of experimental approaches to explore behavioral patterns across a broader range of species. This evolution led to a more nuanced understanding of animal cognition and behavior (Marston & Maple, 2016).

In recent years, our knowledge on this topic has continued to deepen, with a resurgence of comparative studies in areas such as cognition and psychopathology, driving us towards a more comprehensive understanding of the human mind and behavior (Papini, 2020).

Key Concepts in Comparative Psychology

  • Ethology: Ethology is the biological study of animal behavior in their natural environment. In comparative psychology, researchers use ethological approaches to understand how behavior relates to the animal’s natural environments, and those behavioral adaptations can indicate the animal’s evolutionary history (Olmstead & Kuhlmeier, 2015).
  • Innate Behaviors: Innate behaviors refer to the instinctual, automatic responses that are independent of prior experience or learning. Comparative psychologists explore innate behaviors across diverse species to gain insights into how such behaviors have been shaped by natural selection and how they compare to learned behaviors (Weiss, 2018).
  • Learning and Cognition: Learning and cognition cover the various processes of acquiring, organizing, using, and retaining knowledge. Researchers in comparative psychology study these processes across different species, with a strong emphasis on understanding the evolutionary advantages of particular cognitive skills and learning capacities (Papini, 2020).
  • Social Behaviors and Communication: Social behaviors and communication involve interactions between individuals, ranging from competition, cooperation, conflict to exchanges of information. Comparative psychology applies this concept by studying different species’ social and communication behaviors, thereby revealing patterns that highlight shared evolutionary pressures and constraints (Gomez, 2022).
  • Problem Solving and Tool Use: The study of problem solving and tool use involves observing how animals manipulate their environment to overcome obstacles, often through innovative methods. In comparative psychology, such investigations help us understand the cognitive capabilities, indicating the level of mental flexibility and intelligence across species (Marston & Maple, 2016).
  • Cross-species Comparisons: Cross-species comparisons involve contrasting and comparing behaviors, cognitive abilities, and other psychological attributes across different animal species. Comparative psychologists use cross-species comparisons to better understand the evolutionary origins of certain behaviors or attributes and to elucidate why they persist in contemporary species (Papini, 2020).
  • Evolutionary Psychology: Evolutionary psychology is a perspective that applies principles of evolutionary biology, including natural selection and adaptation, to understand the human mind. Comparative psychologists use principles from evolutionary psychology to hypothesize and experiment on behaviors observed in animals, drawing comparisons on how those behaviors are similar, different, and why (Saugstad, 2018).
  • Animal Emotions and Consciousness: Exploring animal emotions and consciousness implies interpreting the subjective experiences of non-human animals. Comparative psychologists examine these aspects to discern parallels between human emotions and animal responses, prompting a broader discussion of consciousness and emotional expression across species (Marston & Maple, 2016).
  • Sensory Perception Across Species: Examining sensory perception across species uncovers how different animals perceive their world. In comparative psychology, such investigations provide insight into the diversity of sensory modalities among various species and often highlight unique adaptions to specific environmental challenges (Olmstead & Kuhlmeier, 2015).
  • Animal Culture and Tradition: The study of animal culture and tradition involves observing and documenting learned behaviors that are passed down through generations within animal groups. Comparative psychologists pay attention to these behaviors to enhance our understanding of social learning, cultural dissemination, and the evolution of customs in different species (Gomez, 2022).

Examples of Comparative Psychology Studies

Alex the Parrot and Language Abilities

Under the tutelage of cognitive scientist Irene Pepperberg, a grey parrot named Alex demonstrated remarkable language abilities exceeding most avian species’ limits.

Alex exhibited understanding of concepts such as color, shape, quantity, and even the concept of ‘zero.’ This study revolutionized the view on bird cognition and presented compelling evidence of complex cognitive processes in non-human species.

Pepperberg’s work offered insights not only into avian cognition but also raised questions about the nature of language and cognition in general (Marston & Maple, 2016).

Primates and Theory of Mind

Theory of Mind refers to the ability to understand that others have beliefs, desires, and intentions that are different from one’s own (Krupenye & Call, 2019).

Studies involving primates, particularly chimpanzees, have explored this concept extensively. Through a series of innovative experiments, primates have demonstrated understanding of deception, empathy, and even perspective-taking, showing a rudimentary form of Theory of Mind. Such findings bridge the gap between human and non-human cognitive abilities and offer insight into the evolution of social cognition (Olmstead & Kuhlmeier, 2015).

Dogs and Human Social Cues

Various studies have tested dogs’ ability to interpret and respond to human social cues.

For instance, dogs can follow human pointing gestures to locate hidden food, showing a level of interspecies communication and understanding that surpasses even our closest non-human relatives, the apes. This highlights the deep emotional and cognitive bonds formed between humans and dogs during the domestication process.

Understanding dogs’ responses to human social cues reveals how they have been shaped through selective breeding for certain behaviors and temperaments (Gomez, 2022).

Cephalopods and Complex Problem Solving

Cephalopods, particularly octopuses, have demonstrated exceptional problem-solving abilities. In various experiments, octopuses have shown the capacity to navigate mazes, unscrew jars to access food, and even use tools, indicative of advanced cognitive abilities.

These findings underpin the rich intellectual life of cephalopods and provide a contrasting perspective to cognition as these marine animals diverged from the human lineage early in evolutionary history. Their independent evolution of complex brains and behaviors offers a fascinating parallel to human cognitive evolution (Papini, 2020).

Methods in Comparative Psychology: The Study of Human & Animal Behavior

A comparative approach to psychology can be achieved in any of the following ways:

1. Observational Studies
Observational studies involve watching and recording the behavior of a subject in its natural context without manipulation or control. It provides an undisturbed and authentic snapshot of an organism’s behavior in its natural environment. In the realm of comparative psychology, observational studies offer dynamic insights into animal behavior, helping researchers draw meaningful correlations between different species and the environments they inhabit (Saugstad, 2018).

2. Controlled Experiments
Controlled experiments refer to research methods where all variables, except the one under investigation, are kept constant or ‘controlled. The purpose of this method is to ascertain whether the variable under study directly impacts the result. In comparative psychology, controlled experiments allow researchers to establish causal relationships, understanding the effect one factor, such as environmental change or a specific stimulus, has on the behavior or cognitive abilities of different species (Marston & Maple, 2016).

3. Cross-species Comparisons
Cross-species comparisons involve contrasting and comparing behaviors, cognitive abilities, and other psychological attributes across different animal species. This method helps in identifying evolutionary trends in behavior, cognition, and related attributes. In comparative psychology, cross-species comparisons are fundamental. They shed light on the evolutionary origins of certain behaviors, cognitive skills, or traits, highlighting core universalities and unique species-specific adaptations (Papini, 2020).

Strengths, Weaknesses, and Criticisms

Comparative psychology offers a lens into the evolution of behavior, cognition, and brain function, drawing knowledge from a wide spectrum of species and cultivating enhanced welfare practices for animals. Yet, it’s not devoid of limitations.

The transfer of findings from animals to humans can present challenges, and the unique traits of individual species occasionally evade satisfactory comparison. In addition, criticisms towards the field often revolve around potential anthropomorphism and a perceived deficit in ethological context, particularly when heavy emphasis is placed on laboratory studies.

These issues are detailed below:

Strengths of Comparative Psychology:

  • Diversity: Comparative psychology involves studying a wide range of species beyond humans (Gomez, 2022). This breadth allows researchers to unveil generalized principles about behavior, cognition, and brain function.
  • Evolutionary Insights: By analyzing behaviors across various species, comparative psychology provides crucial insights into the evolutionary aspects of behavior and cognition (Watson, 2021).
  • Improved Welfare: The principles derived from comparative psychology studies can enhance the well-being and care standards of both wild and captive animals (Marston & Maple, 2016).

Weaknesses of Comparative Psychology:

  • Translation Limitations: While animals provide an efficient research model, extrapolating findings from animal research to human behavior can be challenging and potentially misleading due to biological and cognitive differences (Olmstead & Kuhlmeier, 2015).
  • Limited in Scope: Some traits or behaviors unique to certain species or individual organisms may not be easily compared or may be completely unmatched during cross-species comparisons (Papini, 2020).

Criticisms of Comparative Psychology:

  • Anthropomorphism: Critics argue that comparative psychology often falls into the trap of anthropomorphism—attributing human thoughts, feelings, and intentions to animals (Saugstad, 2018).
  • Lack of Ethological Focus: Some critics argue that by placing a high emphasis on laboratory studies, comparative psychology may overlook valuable ethological context, thereby limiting the comprehensive understanding of animal behavior in their natural environments (Weiss, 2018).


Comparative psychology remains an engaging and fast-developing discipline, unveiling a myriad of insights into the natural world and our place within it.

Through cross-species comparisons and an in-depth examination of behavior and cognition, it provides a unique perspective on the evolutionary origins of our own behavioral patterns and mental processes. Not only does this field yield immense value for fundamental science, but it also has profound implications for practical issues, such as promoting animal welfare and informing human health.


Abramson C. I., McCarthy W. N. IV. (2022). The psychic life of micro-organisms: A study in experimental psychology, A review of the book by Alfred Binet. Int. J Comp. Psychol. 35. Retrieved from:

Abramson, C. (2023). The origin of the phrase comparative psychology: an historical overview. Frontiers in Psychology.

Flourens P. (1861). De la raison du genie et de la folie. Paris: Garnier frères.

Gomez, T. (Ed.). (2022). Comparative Psychology: Evolution and Development of Behavior. Murphy & Moore Publishing.

Krupenye, C., & Call, J. (2019). Theory of mind in animals: Current and future directions. Wiley Interdisciplinary Reviews: Cognitive Science10(6). Doi:

Marston, D. C., & Maple, T. L. (2016). Comparative Psychology for Clinical Psychologists and Therapists: What Animal Behavior Can Tell Us about Human Psychology. Jessica Kingsley Publishers. ISBN: 9781784501617

Olmstead, M. C., & Kuhlmeier, V. A. (2015). Comparative Cognition. Cambridge University Press.

Papini, M. R. (2020). Comparative Psychology: Evolution and Development of Brain and Behavior. Taylor & Francis Group.

Saugstad, P. (2018). A History of Modern Psychology. Cambridge University Press.

Watson, J. B. (2021). Behavior: An Introduction to Comparative Psychology. Legare Street Press.

Weinland, D. F. (1858). A method of comparative animal psychology. Proc.

Weiss, B. A. (2018). Natural Behavior: The Evolution of Behavior in Humans and Animals Using Comparative Psychology and Behavioral Biology. Universal Publishers.

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Dr. Chris Drew is the founder of the Helpful Professor. He holds a PhD in education and has published over 20 articles in scholarly journals. He is the former editor of the Journal of Learning Development in Higher Education. [Image Descriptor: Photo of Chris]

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