A recent study involving over 3,000 dogs has found no link between common genetic variants and behavioral traits, challenging the claims of popular at-home DNA tests. Researchers from the University of Massachusetts analyzed data from the Darwin’s Ark project and concluded that such tests lack predictive accuracy. This finding highlights the complex interplay of genetics and environment in shaping canine personality.
Researchers led by genomicist Kathryn Lord at the University of Massachusetts examined DNA sequences and behavioral surveys from 3,287 dogs participating in the Darwin’s Ark project. Their analysis, published in the Proceedings of the National Academy of Sciences (PNAS) in 2025, tested 151 single-nucleotide polymorphisms (SNPs)—small changes in a single DNA letter—for associations with traits like aggression, drive, and affection. No connections were found, despite earlier research suggesting hundreds of genes could influence dog behavior.
The study warns that unvalidated genetic tests, now marketed directly to pet owners, can lead to misguided decisions. For instance, labeling a dog as genetically prone to aggression might prompt owners to restrict social interactions or shelters to deny adoptions. As Lord and colleagues noted, “Genetic tests for behavioral and personality traits in dogs are now being marketed to pet owners, but their predictive accuracy has not been validated.”
Dog behavior is polygenic, involving interactions among multiple genes across chromosomes, and requires vast datasets—potentially tens or hundreds of thousands of dogs—to uncover meaningful patterns. Even then, genetics accounts for less than half of most traits, sometimes as low as 8 percent, with the remainder influenced by environmental factors like training and experiences. These elements can significantly limit the reliability of genomic predictions.
Prior studies linking SNPs to behavior often relied on breed-average approaches, assigning traits based on breed norms. However, personality varies widely within breeds, making this method circular and prone to false positives, such as confusing behavioral links with physical traits like fur color. The new research replicated none of these associations, attributing them to small sample sizes and incomplete behavioral data in canine genetics compared to human studies.