As every dog owner knows, teaching Fido to lie down and be calm can be a giant hurdle in obedience class. It turns out that at least among German shepherds, genetics may play a big role in whether your pet earns a gold star. Researchers gave 104 of the dogs the lie-down-and-be-calm test and three other behavioral exams, all designed to assess the dogs’ ability to control their impulses. Later, the scientists compared the canines’ DNA, looking specifically at a gene that is connected to the production of dopamine and norepinephrine. These neurotransmitters are involved in emotional responses and the ability to focus, and have been implicated in humans with attention-deficit hyperactivity disorder.
The 37 German shepherds with a shortened version of the gene had the most trouble controlling their impulsive behaviors, regardless of their sex, age or training. But the dogs with long versions of the gene passed the impulse tests with the calm of Zen master. The study, reported in the journal PLoS ONE, may not only help breeders identify hyperactive dogs but also could prove useful in studies of ADHD in humans.