Yes, people of all IQs have bad habits, but some bad habits are more common among high IQ people, while other bad habits are more frequently possessed by lower IQ people. High IQ people may be prone to “overthinking” situations, resulting in indecision and an inability to take action to resolve a problem. In contrast, those of average intelligence tend to be more pragmatic, looking at the big picture and making a decision, unencumbered by considering all the possible outcomes.
Bad habits associated with unhealthy diet, smoking and drug use are more prevalent in people of average or lower intelligence than in those of high intelligence, although all forms of health abuse are evident among a smaller sector of those of high IQ.
Excessive preoccupation with achieving perfection is also found more often among those of high IQ. They can usually see flaws in their work and they strive excessively to reach perfection. In his biography of Leonardo da Vinci, Walter Isaacson reported that Leonardo would seldom declare a painting as finished, because he always felt that it could be improved with yet another brush stroke. Hemmingway reported that he rewrote some of his manuscripts over 100 times.
High IQ people often suffer from preoccupation, sometimes resulting in dangerous behaviors. The brilliant mathematician, John von Neumann cracked up his car several times, because he was always preoccupied with some deep thinking while driving. On one occasion, he explained that his car went off the road, because suddenly the trees by the side of the road turned and came toward him. On another occasion, he pulled off the road and ran into a telephone booth to call an ask his wife where he was supposed to be going that morning.
There is significant overlap in the things that average and high IQ people think about. However, thoughts about the deep issues of physics, existential issues in philosophy and patterns in history tend to be the domain of the high IQ people. Most people of average IQ are not interested in mathematics at an advanced level or whether there is a conflict between determinism and free will. They tend to be more interested in practical issues and regard abstract or academic issues as irrelevant in daily life. For more information on such differences, visit: What do smart people do in their free time? – Intelligence and IQ
