Blood typing is just a convenient, nonracial genetic indicator… available to all.
It’s important to keep in mind that blood type correlations are imperfect, since genetics are actually more varied than you can express with a mere 4 blood types. (The American Redcross actually has identified more than 400 subtypes)
However, that doesn’t mean that it’s not more useful than not. Newtonian physics is still used due to convenience, even though Einstein’s work provides greater accuracy.
“The Blood Type Diet” from Dr. D’Adamo seems to work for far more people than it doesn’t. Having seen it work in as many cases as it does is what made start to catalog psychological and pheromonal attributes in regards to blood type.
Most Type Os I run into definitely tend to be more primal than most, and with a sort of raw energy. They also tend to gravitate toward meat heavy diets, since that’s what makes most Os naturally feel best.
Androstenone can definitely amplify the overall presence of Os into something that can appear to be threatening or even vicious. That’s why it seems that many Os do best with less -none, and better with pheromones that make them more approachable.
Just for fun, start asking people you know what their blood type is. After awhile, you should start to see patterns emerge. It’s both fun and fascinating.
(btw, everyone reading this should enter their blood type into their user profile)