Is Blood Type Personality Real?

Medically reviewed by Melissa Guarnaccia, LCSW
Updated February 21, 2024by BetterHelp Editorial Team

In America, some people look up a potential partner's star sign to see their personality type and compatibility. If you are not too shy to admit it, you may have sought advice on this and relationships from the stars at one time or another. Some people do not rely on the astrological signs of personality information but rather on their biological markers. Continue reading to learn about this unique take on what makes us individuals and see how it may apply to you or someone you know. We will also provide resources for online therapy services if you're interested in diving deeper into self-discovery.

Blood type personality, though interesting, is not legitimate

What is blood type personality?

In Japanese society, the dating set might ask someone what their blood type is to learn more about them. It may surprise you to learn there is a whole blood type personality theory that has become popularized in Japan.The concept of blood type personalities might seem foreign to us, yet understanding blood typing is quite popular in certain countries. Some believe that personality traits are inherently connected to your blood type. Although a potential link between blood type and personality is a fun idea, there's currently no scientific proof to back up blood personality type, meaning the overall theory of blood type personalities is to be viewed as more of a fun exploration than a scientific pursuit.

Similar to how some Americans like to entertain the idea of astrology and horoscopes for fun, some people in Japan enjoy exploring their personality and how it might relate to blood type. One study showed that 99% of Japanese people know their blood types, though it’s important to note that it’s common for many people, regardless of ethnicity, to know their blood type for medical reasons. Nonetheless, the Japan Times has embraced this fun theory and has written popular articles on how the primary blood types indicate personality traits.

Furukawa and blood type personality theory

The idea of blood type influencing one’s personality isn’t restricted to Japan and may not have even originated there. According to an article in Scientific American magazine, ancient philosophers such as Hippocrates and Aristotle explored the notion of a person’s personality based on different blood types. The article goes on to say that Japanese Professor Tokeji Furukawa chose blood as a physiological characteristic that could be classified according to types. His work was the basis for 204 publications by other researchers that discuss the connection between blood types and personality.

There are four primary blood types: A, B, A/B, and O. According to personality theory, the type of blood you have indicates the type of person you are, and the type of blood you have directly correlates to one of four personality types.  It’s important to note that, again, the ideas below are not backed by consistent information and should be considered more of a fun idea to explore rather than absolute markers of personality or individual identity. Everyone exists on a spectrum, and none of us can be summed up or defined simply by our blood type. As you read this, you are likely to identify with all or multiple of the descriptions to some degree or another, regardless of your blood type.

Blood type A personality

People with blood type A may be clever, passionate, sensitive, and cooperative. They can be loyal and patient, and they love peace. Sometimes, they may be overly sensitive about different things as compared with other blood types. For instance, they might care a lot about etiquette as well as social standards. According to blood type personality theory, A personalities do not like to break the set rules on etiquette or the societal standards or rules that have been laid down. Occasions when they choose to break the rules are considered self-fulfilling prophecies.

A blood type personalities are considered careful decision-makers, and they can be known to take their time before they can settle on any decision. Moreover, they are not efficient at multi-tasking, as they prefer to handle one task at a time. Blood type A people are very organized, and they may not like haphazard actions. These blood type personalities prefer to keep everything neat and in the right place. In fact, they may go to great lengths to keep things neat and tidy. They might plan everything, and every task they engage in may be carried out with much consistency and seriousness. Many people with OCD fall may into this category and may benefit from seeking help from a professional counselor who can help with overcoming obsessive-compulsive behaviors, if desired.

People in the A blood type category may be very stubborn and easily stressed. They may have higher levels of the stress hormone cortisol, and this can cause them to be perceived as intense. They do not like fights and prefer to be in harmony with everyone, and they like to work in collaboration with others in the community. They tend to keep to themselves more so when they do not want to confer their ideas or opinions. Some of the most common traits of blood type A are as follows:

  • Kind
  • Shy
  • Stubborn
  • Attentive
  • Composed
  • Polite
  • Tense
  • Withdrawn
  • Reliable
  • Perfectionistic
  • Sensitive
  • Tactful
  • Anxious
  • Earnest

As friends, people with type A are considered very reliable and trustworthy. If you are in trouble, you can rely on friends with this blood type. They may not like to show their emotions; they keep their thoughts or feelings about things hidden from others, and they only show vulnerability when comfortable. Famous people with blood type A include George Bush, Jet Li, Britney Spears, and Richard Nixon.

Blood type B personality

People with the B blood type may be more likely to be creative individuals. Individuals who have B blood may make their decisions quickly, and they are not good at taking orders. When type B blood people focus on something, they put their all into it, and they are unlikely to let go, even if the goal seems unachievable or impractical. People with a B blood type can have a very strong drive or desire to be the best at anything that they have set their minds to do. Nevertheless, according to blood type personality theory, people with this blood type are poor at multitasking. They are likely to neglect other important tasks and put all their focus on whatever they have set their mind on at the moment.

Getty/Luis Alvarez

B blood type people might face a lot of discrimination because of their potential negative personality traits, such as a tendency to be more selfish or uncooperative and stubborn at times. Society mainly focuses on the negative side of people with blood type B, even though people with this blood type (like any person) have many good qualities, too. As a result, they may tend to be loners, and may isolate themselves from others more so than other blood types. 

Blood type personality theory states that they may tend to approach things at their own pace. Some of the most common positive traits of people with blood type B include the following:

  • Curious
  • Relaxed
  • Strong
  • Adventurous
  • Creative
  • Passionate
  • Active
  • Outgoing
  • Cheerful

On the other hand, negative traits can include being “wild,” erratic, unforgiving, selfish, uncooperative, irresponsible, or unpredictable. Bs are generally a balance of As and Os, as they are both thoughtful and ambitious. Famous people with type B include Vince Young, Leonardo DiCaprio, and Jack Nicholson. People with blood type B are more compatible with fellow blood type Bs, but they can also relate well with blood type AB.

Blood type AB personality

Blood type AB, based on the theory, is a mix of A and B personality types. People consider AB types to be complicated and double-sided. For instance, they can be outgoing just like Bs but also shy. At times, people view this blood type as having double personalities, and ABs may keep their true personalities from strangers. It is hard for a stranger to instantly decide which personality people with type AB have until they get to know them. 

People with the AB blood type are considered the rarest in the world. AB blood type people are empathetic, and they are likely to be careful when interacting with others. They make sure that they consider other people's points of view. These people have exceptional logical and analytical skills, and they are seen as humanists.

Some of AB blood types’ good traits can include the following:

  • Caring
  • Charming
  • Composed
  • Dependable
  • Sociable
  • Ambitious
  • Adaptable
  • Diplomatic
  • Rational

An AB personality’s negative traits can include being self-centered, irresponsible, vulnerable, indecisive, forgetful, unforgiving, and critical. Famous people with AB blood types include Barack Obama, Marilyn Monroe, Jackie Chan, and John F. Kennedy.

Blood type O personality

People with blood type O are considered to be outgoing, go-getters, and daring. Blood type personality theory states that they usually set high standards for themselves, and they do all they can to achieve them. Blood type Os have excellent leadership capabilities. Little things do not concern them, and this may make them appear selfish to people in blood group A who may be overly sensitive. 

Some of the positive personality traits in people with blood type O include the following: 

  • Self-determined
  • Easygoing
  • Optimistic
  • Confident
  • Loyal
  • Cautious
  • Passionate
  • Resilient
  • Devoted

On the negative end of the spectrum, Os can be jealous, rude, ruthless, insensitive, unpunctual, unpredictable, cold, self-centered, workaholics, and arrogant. 

Individuals with blood type O are very enduring and strong, and that is why the Japanese call them warriors. They are honest people and despise people who tell a lie or hide the truth. People who are O are not overly cautious about small details, as they tend to focus more on the big picture. Famous people with blood type O include Queen Elizabeth II, Paul Newman, Elvis Presley, Ronald Regan, John Gotti, and Gerald Ford.

Medical concerns regarding blood typing

While blood typing has been somewhat studied as a form of social psychology, scientific research and peer reviewed studies have primarily explored how blood type and the immune system works in connection with diseases such as cardiac disease and stomach cancer. Blood typing may help identify an increased risk of heart disease depending on a person’s blood type. Heart disease is particularly concerning for pregnant women who may have weaker immune systems depending on their blood types. 

Furthermore, various blood types have also been connected to an increased risk of stomach cancer. The number of a person’s red blood cells is directly related to the strength of a person’s immunity against bacteria and infections. 

New research shows that red blood cells are immune sensors in our bodies which could be a clue for diagnosing infections in critically ill people.

In pregnant women, the heart has to work harder, causing stress to the heart and blood vessels. There is an increase in blood volume and cardiac output which increases a pregnant woman’s heart rate. At the same time, blood pressure can decrease during pregnancy, causing a pregnant woman to feel short of breath and light-headed. According to the Harvard School of Public Health, women who have blood types A, B, or AB have an increased risk of cardiac disease. In relation to cancer and blood typing, one study found that people with type A blood had an increased risk of stomach cancer while people with type O blood had a slightly decreased risk of stomach cancer. The reason is that people with blood type A are more prone to H. pylori infections.

Regardless of your blood type, whenever you have a serious physical condition, it can impact your mental health. If this occurs, a licensed therapist can help you cope with trying times.

Blood type personality, though interesting, is not legitimate

Can I change undesirable aspects of my personality?

As previously emphasized, blood type personality theory has not been confirmed by peer-reviewed research. That said, it is worth thinking about why one would choose to consult a personality assessment, like a blood type personality questionnaire, enneagram test, or Myers-Briggs personality assessment. Perhaps this decision indicates a curiosity to uncover information about our strengths and weaknesses. In this situation, licensed healthcare professionals are a more reliable resource.

Is there a personality trait you have that others find undesirable? Are you interested in changing your habits or coping mechanisms in the face of challenges? Online therapy may be a beneficial option for you, especially since it allows you to schedule appointments at a time that works for your schedule. Additionally, you can attend an appointment from any location with a reliable internet connection. For more reserved personalities, these benefits may make seeking support more convenient.

Online therapists can use a variety of treatment approaches, including cognitive behavioral therapy (CBT), to help participants achieve their goals. When it comes to changing personality traits, specifically, internet-based CBT has been found effective as an intervention for improving symptoms of neuroticism when it comes to severe health anxiety. In a separate study, researchers screened undergraduate college students for maladaptive perfectionism and utilized a web-based CBT approach to effect positive changes in depression, anxiety, stress, and automatic thoughts.


Blood type personality theory is a fascinating topic that can make for interesting discussions in any circle. That said, personalities aren’t always easy to understand. If you’re struggling to understand your own personality or the personality of someone you care about, a licensed therapist can help you sort things out. If you're interested in learning more about yourself to improve, therapy is a great option. BetterHelp offers convenient and trustworthy therapy at an affordable price.

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