If you guessed a rare blood type, you got it right. All three of them have (had) AB Negative blood type.
The Rarest Blood Type and Universal Plasma Donor
The nature of antigens present in the serum determines the blood type. AB negative suggests that an individual has both the antigens A and B. Individuals who are AB blood group are commonly called universal plasma donors because their plasma can be transfused to any person of whatever blood group. The blood type is also the rarest blood types among all the blood group because it is present in only 1 out of 167 individuals. This means an approximately 0.6% of the population has an AB negative blood. Not all of the ethnic groups share the same proportions of the AB negative blood type though. This blood type is present in about 1% in Caucasians, 0.3% in African American, 0.2% in Hispanic, and 0.1% in Asian. source link
About 15 percent of Caucasians are Rh negative while 5 to 10 percent of African Americans don't have the protein on the red blood cells. 1 to 2 percent of Asians are negative for the protein.
Highest Rh negative Rate
Those with ancestral roots in Basque provinces in Spain and France have the highest incidence of Rh negative blood than others around the world. Rh negative blood has been found to be significantly higher in Basques than those in neighboring European countries as well as other regions in Spain and France. 27 percent of Basques have type O Rh negative blood. source link
Former President Eisenhower Type O-Neg
Former President Richard Nixon Type O-Neg
Former President Gerald Ford Type A-Neg
Former President Jimmy Carter Type A-Neg source
Former President George W. Bush Sr. Type A-Neg
Former President Bill Clinton AB-Neg
Former President Barack Obama AB-Neg source
President Donald Trump RH-Neg but his ABO group is so far unreported
Source unless otherwise noted
Statistical probability of the 8 of the last 13 presidents being RH-Neg? I don't have the answer, but it wouldn't surprise me if it is lower than the chances of winning the lottery.
Right-handedness is the most common type and the most dominant. Right-handed people are more skilled in performing tasks with the right hand. An overwhelming majority of people on the planet are right handed. As a result, most gadgets and devices are designed with the right-hand use in mind. Studies suggest that 70-95 percent of individuals have the right hand as the more dominant one. Left-handedness is less common and can be found in about 10-12 percent of individuals on earth. source
So, of the last 13 presidents, you might estimate that one, or perhaps two to be left handed, but amazingly six of 13 were left-handed!
Harry S. Truman
Gerald Ford
Ronald Reagan
George H.W. Bush
Bill Clinton
Barack Obama
Clinton and Obama were AB-Neg and left-handed, what is the probability of that?
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