In this hypothesis Type A, personalities that are more competitive, highly organized, ambitious, impatient, relaxed, flexible with situations.

A personality, by definition, are noted to live at lower stress levels. They typically work steadily, and may enjoy achievement, although they have a greater tendency to disregard physical or mental stress when they do not achieve.

Type A personality is characterized by impatience, a chronic sense of time urgency, enhanced competitiveness, aggressive drive, and often some hostility. 

A-personalities are true introverts who are extremely hard workers.

With a type A personality are natural pessimists and are often living with a lot of stress.