Introverts are able to concentrate more intensely and for longer periods of time than extroverts. Introverts are easier to train. Mental fatigue builds up more quickly in extroverts and their attention tends to flag. Unless given frequent breaks, they will not do as well as introverts on tests that require concentration. Perhaps due to a shorter attention span, extroverts are more prone to accidents (e.g., have more frequent automobile accidents). The upside is that extroverts are less likely to be worriers. (Blitchington, Peter, PhD and Robert Cruise PhD. Understanding Your Temperament. p 11-14. MI: Andrews University Press, 1979)