I remember my Dad having a copy of Life Magazine back in the 60's .... unfortunately I no longer have the copy and it's so long ago, it appears no digital copy is available. I cannot remember who the author of the study was, but the facts from the study were garnered from bite incidents in the NYC area where a hospital visit was needed over a 10 year period. Although not breed specific, the results were tabulated by group. And which group over 10 years had the greatest number of reported dog bites ... dogs that fall into the working group of breeds. (Second greatest number of bites was from the toy group)
IMO ... not a big surprise as any breed where the specific dog's job bred over generations has been to protect (person, animals, property, etc). This is not to generalize and say that these breeds cannot make a wonderful companion BUT in the right hands. It never ceases to amaze me when people who are NOT dog or NOT dog training savy, pick one of these breeds as a house pet and then are surprised when something happens.