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Psychological evolution process of blood type o

O-type people are docile and pleasant in adolescence, but as they grow older, they will become more and more self-assertive and not solicit the opinions of others, thus becoming very courageous and outspoken people.

This blood type is regarded as the most psychologically changed among all blood types. He is young and obedient, but becomes very tough when he is old. ( Blood type and personality http:///xx/)