Neoteny and the Modern Dog
Guest Post by Carrie Faber-Johnston, M.S., CYNX-L
When people wonder why some dogs seem easier to train, more playful, or more people-oriented than others, the explanation often goes deeper than individual effort or training technique. According to canine scientists and behavior professionals, much of the answer lies in biology - specifically in a developmental process known as neoteny and the long history of human-driven selection that shaped the modern dog.
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Understanding how neoteny influences behavior can help prospective owners, trainers, and handlers make better-informed decisions, moving beyond trends and appearances toward genuine compatibility between dogs and humans.
The Science Behind Staying Young
Neoteny refers to the retention of juvenile traits into adulthood. In biological terms, it is a form of paedomorphosis, in which development slows or shifts so that youthful characteristics persist later in life.
In domestic dogs, neoteny appears in both physical and behavioral forms. Physically, neotenous dogs often retain rounder skulls, larger eyes, shorter muzzles, and softer facial features - traits commonly associated with puppies. Behaviorally, neoteny is expressed through prolonged playfulness, increased social tolerance, reduced aggression, and a strong orientation toward humans.
These traits weren’t accidental, early humans consistently favored animals that were easier to live with - less reactive, more flexible, and more socially attuned. Over generations, those preferences reshaped canine development itself.
From Wolves to Companions: The Role of Neotenization
While neoteny describes the traits, neotenization refers to the process by which humans - intentionally or unintentionally - selected for those juvenile characteristics. During domestication, animals that tolerated human proximity, recovered quickly from stress, and engaged socially were more likely to survive and reproduce. This selection altered developmental timing, skull structure, hormonal systems related to stress and arousal, and learning tendencies.
Modern research confirms that dog domestication involved both the retention of juvenile traits and the emergence of new ones, particularly in social cognition and human-directed behavior. The result is the remarkable diversity of dogs seen today.
Why Breed Differences Matter
Not all dog breeds express neoteny to the same degree. According to trainers and researchers alike, this variation plays a major role in behavior, trainability, and suitability for different roles. Breeds developed for companionship or close cooperation with humans - such as Labrador Retrievers and Golden Retrievers - tend to be highly neotenous. These dogs often remain playful well into adulthood, show strong motivation to engage with people, and respond readily to social reinforcement. Those specific qualities are one reason retrievers dominate service dog and assistance programs. Neotenous traits support emotional resilience, social tolerance, willingness to repeat behaviors, and prolonged learning capacity.
By contrast, breeds closer to ancient or “primitive” lineages, such as Shiba Inus and Basenjis, tend to be far less neotenous. These dogs often mature behaviorally earlier, display greater independence, and rely less on human social approval. While highly capable, they may not naturally seek constant cooperation with people - an expectation mismatch that can lead to frustration for uninformed owners.
Importantly, professionals caution against interpreting independence as stubbornness or lack of intelligence. “These dogs simply engage with the world differently,” trainers note, emphasizing that success depends on aligning expectations and training methods with a dog’s natural tendencies.
What the Brain Reveals
Advances in neuroimaging have added scientific support to long-standing observations in the training world. MRI studies show that brain structure varies significantly across breeds and correlates closely with historical function. Modern, highly neotenized breeds often show neural patterns associated with social learning and behavioral flexibility. More primitive lineages retain brain organization closer to ancestral canids, supporting independence and environmental problem-solving. The implication is clear: training success depends as much on biological compatibility as on technique.
Choosing the Right Dog
Behavior professionals argue that many dogs struggle not because they are “difficult,” but because expectations do not match biology. Understanding neoteny allows owners to choose breeds aligned with their lifestyle, set realistic expectations for maturity and behavior, and avoid labeling normal breed traits as problems. A highly neotenous dog may thrive on repetition, play-based learning, and close partnership. A less neotenous dog may require autonomy, purpose-driven work, and respect for instinctual behavior. Neither approach is superior. The key is fit.
Lessons From Service Dog Programs
The practical importance of neoteny becomes especially clear in service dog work. During training programs led by pioneers such as Dr. Bonnie Bergin, neoteny was directly linked to success rates. Highly neotenized breeds - particularly Labrador Retrievers and Golden Retrievers - consistently outperformed others in demanding service roles, including guide dog work. These dogs retained juvenile traits such as social flexibility, emotional resilience, and openness to learning, all essential for navigating complex human environments. Historically, German Shepherds were among the first guide dogs, reflecting the origins of organized guide dog training in Germany during World War I. Over time, however, many programs transitioned to retrievers and later to Labrador-Golden crosses to improve consistency and adaptability.This shift, does not reflect a hierarchy of breeds but a recognition that certain developmental traits are better suited to specific demands.
A Framework for Success
When selecting or training a dog, professionals recommend considering breed history, degree of neoteny, motivation systems, and learning style. When these factors align, training becomes clearer, relationships deepen, and fulfillment increases—for both dogs and humans.
As science continues to illuminate the biological foundations of canine behavior, one conclusion stands out: understanding what kind of dog you have may be the most powerful training tool of all.
Selected Scientific References
Geiger, M., et al. (2017). Neomorphosis and heterochrony of skull shape in dog domestication. Scientific Reports.
Berns, G. S., Brooks, A. M., & Spivak, M. (2019). Significant neuroanatomical variation among domestic dog breeds. Journal of Neuroscience.
Marshall‑Pescini, S., et al. (2017). The effects of domestication and ontogeny on cognition in dogs and wolves. Scientific Reports.
Croston, R., et al. (2024). Breed differences in social cognition, inhibitory control, and problem‑solving in domestic dogs. Applied Animal Behaviour Science.
Driver, E. M., et al. (2023). Breed function and behaviour correlate with endocranial volume in domestic dogs. Biology Letters.