Among Type A individuals, the trait that appears to be most harmful to health is ___.

Answer: Hostility

Explanation:

Hostility according to Oxford dictionary refers to unfriendly or aggressive behaviour.

Type As are said to experience more hostility which has been associated with an enhanced risk of heart disease. Researchers have discovered that it increase coronary artery disease.

This is because people with Type personality focuses more on the negative when they don't succeed on their competition to success, and they beat themselves up with everything that goes wrong in their lives. As a result they find it hard to copy with stress because they are always on the rush aggressively wanting to be ahead of everyone else; without paying attention to their own state of mind and health.