Fearlessness in the Genes: Working German Shepherds Differ From Show Dogs

The results were consistent. Åke Hedhammar, professor emeritus at the Swedish University of Agricultural Sciences, said: "We could see that, on average, the working dogs showed less fear and more curiosity and were able to socialize well with humans. This shows how important it is to select for behavior when selecting dogs for breeding for important functional roles in our community."

What did the genome reveal?

Behavior descriptions alone could not settle the question of whether the split between working and show lines ran deeper than training. So the researchers took blood samples from 373 German shepherds that had completed the DMA and mapped their genomes.

The comparison surfaced genomic regions that varied according to how curious or playful the dogs were. Kerstin Lindblad-Toh, professor of comparative genomics at Uppsala University and one of the study's leaders, said: "That meant that we were able to identify some of the genes in working dogs that are linked to curiosity and playfulness."

The selection, she noted, was no accident. "Breeders of working dogs have selected and bred the ones that really enjoy working; it's a bit like a game for them," Lindblad-Toh said. "It's interesting that we can now see that this selective breeding has indeed led to differences between working dogs and show dogs among German shepherds — differences that can be seen at both the behavioral and genetic levels."

Why does this matter for humans?

The overlap with human genetics is the study's most intriguing thread. Researchers have long found links between genes and behavior in people, and some of the genes now tied to German shepherd temperament were previously associated with neuroticism in humans.

"So we now have an example of how we might also acquire more knowledge about different behaviors in people with the help of dogs in the long term," Lindblad-Toh said.

That prospect remains distant, and the researchers are careful about it. Behavior is not governed by single genes; it emerges from a complex interaction among many of them. The current results identify candidate regions, not a deterministic code for courage or anxiety.

What comes next?

In collaboration with the Swedish Armed Forces, the team now plans larger studies to map the genetics of behavior more completely. The eventual goal is practical: identifying which dogs have the best prospects of becoming good working dogs, and which should be chosen for breeding.

Hedhammar urged patience. "But we are not there yet," he said. "This study is just a first step and shows that there are actually clear differences in behavior between working German shepherd dogs and German shepherd show dogs."

The paper, by Voichita D. Marinescu and colleagues, appears in Animal Genetics (DOI: 10.1002/age.70221).