Why did comparative psychologists often study guinea pigs, mice, rats, and monkeys?

Comparative psychologists and researchers utilize animals like guinea pigs, mice, rats, and monkeys because these species serve as effective animal models for studying biological and psychological processes.12

These animals are frequently chosen for several practical and scientific reasons:

• Experimental Control: Unlike human subjects, these animals can be kept in controlled laboratory environments where their diet, environment, and history are strictly regulated, allowing for more accurate data collection.341
• Biological Similarity: As mammals, these species share significant physiological and genetic similarities with humans, making them susceptible to many of the same conditions and illnesses.15
• Practicality: These animals are easier to obtain in large numbers and possess shorter life cycles than humans, which enables researchers to study the effects of treatments, genetic manipulations, or behavioral changes across an entire lifespan or multiple generations.315
• Ethical Considerations: Using animal models allows scientists to conduct research that would be unethical to perform on human volunteers, particularly when testing for potential toxicity or invasive experimental procedures.5

Researchers remain committed to the ethical principle of minimizing animal suffering through the "three Rs" principle: replacement, reduction, and refinement.1