Does blood type determine personality?

The relationship between constellation blood type and personality is always the most popular topic among urban white-collar workers. Some people sneered at it, but some people were happy about it. For many white-collar workers, whether a couple of different blood types may quarrel, who is a good match with whose constellation can be matched together, etc. gossip is an indispensable condiment after tea and meals every day.

According to a description in a very best-selling book in Japan [1]: Type O people love life and value strength; Type A people value external reflections and are perfectionists; Type B people do their own way and have a wide range of interests; Type AB people have one mind and two minds. Use, free and unrestrained. If you really use the relationship between different blood types and different personalities written in the book to compare with colleagues around you, some people may exclaim "too accurate", and some people will complain "not accurate at all." Whether it is accurate or not, maybe scientists can help you answer this question.

Although blood types and horoscopes often appear on the same page of newspapers and magazines, in contrast, blood type personality theory seems more scientific. Even people who regard articles such as horoscopes as pseudo-science may agree that blood types are right. Personality has an impact, and the close relationship between blood type and the medical field may deepen this impression. Blood type is a method of classifying blood[2], and the classification is based on whether there are certain heritable substances on the surface of red blood cells. In layman's terms, blood type is a method of classifying the blood of different people according to the substances on the surface of red blood cells, and this marker substance on the surface of red blood cells is usually determined by genes for each person, which is born and unchanged for life. Since the Austrian scientist Karl Landsteiner first discovered the ABO blood type in his laboratory in Vienna in 1900, scientists have so far discovered hundreds of blood type systems including Rh blood type, Lewis blood type, etc. (that is, different blood types). method). Of these blood group systems, the most widely known is naturally the ABO blood group system. Usually what people talk about is the ABO blood group system that is related to personality.

The first to propose the relationship between ABO blood type and personality was the Japanese Furukawa Takeji [3]. He put forward the hypothesis in 1927 that "people have different temperaments due to different blood types; the same blood type has a common temperament" hypothesis. Between the time when the two world wars, from the 1895 Sino-Japanese War defeat the Manchu paper with a "Treaty of Shimonoseki" ceded Taiwan to Japan for more than thirty years. Furukawa’s hypothesis actually served Japan’s colonial rule in Taiwan. According to Furukawa's theory [4], the proportion of blood type O in the Taiwanese population is as high as 41.2%, which is much higher than that of the Japanese population. People with type O blood are "daring, aggressive, like to command others, confident, strong-willed, and aggressive." Therefore, people with blood type O are more aggressive. In contrast, only 23.8% of the Ainu ethnic minority living in northeastern Japan have type O blood, and the Ainu are more gentle and submissive than the Taiwanese. Furukawa used this to explain why the Taiwanese have to continue to resist the Japanese rule. Accordingly, he also suggested to the authorities to promote close marriages between Taiwanese to reduce the proportion of O-type blood among Taiwanese.

From Furukawa’s proposal, we can see how absurd his theory is. These bizarre studies are not uncommon in countries under fascist rule[5]. Scientists in Nazi Germany have conducted investigations on the blood types of different races and found differences in the distribution of blood types of different races, and derived " The absurd conclusion that the blood of the Germanic race is more noble. The crazy experiment that tried to use blood type to prove the superiority of race finally came to an end after World War II. The relationship between blood type and personality began to enter the attention of scientists as a purely scientific topic.

However, it is not so easy to figure out the relationship between blood type and personality. Different blood types can be easily distinguished through blood tests. How to distinguish different personalities?

Personality refers to a person's consistent and stable psychological characteristics, way of thinking and behavior. It is not easy to quantify these rather subjective characteristics in a scientific way. The most commonly used method by scientists is to use various questionnaires to analyze the personality of the subjects through the results of the questionnaires. These questionnaires are made by professional psychology or psychiatric experts, and after repeated calibration and revision, they can objectively reflect the personality characteristics of the subjects. Commonly used questionnaires include Minnesota Multiple Personality Test (MMPI), Eysenck Personality Test (EPQ), Cartel 16 Personality Factors Questionnaire (16PF), Yatabe-Guilford (YG) Personality Test and so on. The results of these tests usually divide a person's personality into different perspectives for analysis. The high or low scores obtained by subjects from a certain perspective represent completely opposite personality characteristics. For example, the 16PF test divides a person’s personality into 16 angles (the so-called "dimensions"). Those with low scores on one of the "N: Sophistication" dimensions are more frank, straightforward, and naive, while those with high scores are very shrewd and capable. , Very sophisticated; people with low scores on the "H: Dare to do" dimension are timid and retreat, lack self-confidence, and those with high scores are risky and dare to do things with little scruples. By analyzing the performance of the subjects in these "dimensions" one by one, the researcher can roughly outline the overall picture of their personality.