My summary from Mr. Masahiko NOMI's book "Ketsueki-gata Josei Hakusho" (Blood-Type Woman White Paper).
Basic personality of type A is rather difficult to describe. However, there are two major ones: 1) sensitiveness to the society and 2) safe
The former equals with type O's sensitiveness to the power. The range of the "society" differs by individuals. A Japanese proverb says "the shame of journey is scraping" [What happens in Vegas stays in Vegas]. It is really for type A. It is a journey that type A get out from the society.
There are many type-A "honor students". Type-A people usually respect social customs, rules and common sense. However, to the contrary, some Type-A people repels worldly things. Both come from the sensitiveness to the society.
Generally, the former is seem to occupy majority. I have an impression -- maybe due to racial differences -- that there are more strong active type As in Westerners.
Another personality, perfectionism, already appears in even infant period.
The perfectionism is applied to everyone. Even scrupulousness, elaborateness, prudence etc. are born from the strong sense of responsibility and independence. On the other hands, perfectionism for other people is easily to become a "type A of nag".
The perfectionism and the unyielding nature is easily combined to form argumentative personality. The fame of obstinate stubbornness prevails. Type A seldom apologizes. Gentleness and stubbornness, these may be one of the Type A's of dual nature.
Shigeyuki Yamaoka (2001), A Psychology Book for not to Become a Useless Adult
Self report of personality from 1 (strongly disagree) to 5 (strongly agree); Subjects are 649 university students who love blood-typical topics.
I have many comments because there are many many type As around me. First of all, the fundamental characteristic of type A is the "intensity of internal feelings" and logic of "should be". I think that Japanese "family" culture which distinguishes "in" and "out" is from type A.
If perfectionism appears well, a person becomes an honor student. Also, even "Wa" [Harmony] -- the core culture of Japan -- is from type A.
Foreigners (Westerners?) are said to have strong feelings of self-assertion than Japanese. If one is in "assert-oneself" culture, type A becomes self assertive, as Type A is deeply concerned with the society.
But I am deeply impressed with type A's careful and warmhearted nature many times.