Link to the paper in Science: Ancestry-inclusive dog genomics challenges popular breed stereotypes.
Environment and socialization remain the largest determining factor.
Unsurprisingly, most stereotypes about dog breeds are pseudoscience that come from the eugenics movement. In particular, “popular knowledge” around pitbulls and bulldogs is just thinly veiled racism.
interview on the study from the verge: https://www.theverge.com/2022/4/28/23043508/dog-breed-behavior-genetics-study-stereotypes
The research did find some genes associated with traits like human sociability and howling frequency. But overall, only around 9 percent of dog behavior was explained by breed.
“Dogs are individuals,” said Marjie Alonso, a study author and executive director of the International Association of Animal Behavior Consultants. “What a dog looks like is not really going to tell you what the dog acts like.”
Edit: modern “purebred” breeding literally came from eugenicists, that’s why this old political cartoon even exists. Documentary on pedigree dogs and their many issues: https://vimeo.com/166015460
"We at Hexbear.net present to you the long awaited sequel to the outdoor cat struggle session."
White people let go of eugenics challenge (IMPOSSIBLE)