I was a little concerned an article like this might validate eugenic arguments, but thankfully no

But, overall, breed is a poor predictor of behavior, and there is more variation within breeds than between them, scientists have found. Someone who wants a friendly, fetch-loving dog that doesn’t bark can’t bank on getting exactly that just by bringing home a Labrador retriever. “You may get exactly the opposite of that,” Dr. Lord said.

…

“There’s no breed,” Dr. Lord said. “They’re just dogs.”