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
I didn't shift. I just fully understand that there's exactly one breed over which breed characteristics is a hot button issue, and so I'm just anticipating the discursive application of these results.
Whether or not eugenicists were involved in early dog breeding (which, if you look at breeds like German shepherds or pugs, is obviously evil) has no relevance whatsoever on the existence of dog breed behavioral characteristics.
The only people I've known with poorly socialized pitbulls have been white rednecks bragging about how their huntin pit needed a train chain to be kept away from other dogs at home. The only ones with well socialized pits who I still saw maul a kid were white suburban people. The danger from pitbulls is empirical, and trying to paint your opponents as bigoted is a despicable exploitation of racial tension for rhetorical purpose. And one that's totally unnecessary given that the data is right there.