Published as Genetics and the Social Behavior of the Dog, the work of John Paul Scott and John L. Fuller represents one of the most comprehensive studies ever undertaken on canine behavior. Over two decades at the Jackson Laboratory, the authors examined how heredity, breed characteristics, and developmental factors interact to shape behavioral outcomes in dogs.
The research systematically compared multiple dog breeds and their crosses, investigating traits such as sociality, learning ability, aggression, problem solving, and communication. Through controlled breeding experiments and standardized behavioral tests, Scott and Fuller demonstrated that many aspects of dog behavior are heritable, but also profoundly shaped by early environmental experience.
A major contribution of their work was the identification of critical periods of socialization, particularly the early window in which puppies form attachments, learn social cues, and adapt to human environments. Puppies deprived of appropriate social contact during these sensitive phases exhibited long-term behavioral deficits, while those raised with structured exposure developed more stable and socially competent temperaments.
Scott and Fuller also showed that breeds differ systematically in behavioral tendencies—including responsiveness, aggression thresholds, trainability, and exploratory behavior—with genetic lines exhibiting consistent patterns across generations. Their controlled crosses further revealed how specific traits combine, segregate, or dilute under different breeding pairings.
The importance of this work continues to be recognized across fields ranging from ethology and veterinary behavior to dog training and responsible breeding. Experts widely regard it as the foundational text on canine behavioral genetics, providing evidence-based principles for understanding how nature and nurture interact in shaping companion animals.
Source: Scott, J. P., & Fuller, J. (1974). Genetics and the Social Behavior of the Dog. 20-year research program conducted at the Jackson Laboratory.
