The concept of a true error-prone personality is very contentious. Many experts however think that some personality traits may predispose people to making mistakes. For example, the psychologist James Reason, in his book The Human Contribution: Unsafe Acts, Accidents, and Heroic Recoveries, pointed out that extreme introverts and extreme extroverts – those at the ends of the personality trait of extraversion – have a higher liability to making errors. Charles Vincent on the other hand, writing in his book Patient Safety, identified those at the lower end of the personality trait of conscientiousness to be more susceptible to making errors; this, he argued, is because such people are less likely to check things over, and less likely to carry out tasks themselves.

Absent-mindedness is another personality trait that is understandably associated with error-proneness. This subject was addressed by James Reason and Klara Mycielska in their book Absent-Minded? The psychology of mental lapses and everyday errors in which they highlighted the paradox that absent mined errors are more likely to be committed by experts than by novices. They explained that this is because such mistakes are ‘a characteristic of highly-skilled or habitual activities’, asserting that ‘the likelihood of making an absent-minded slip actually increases the more proficient we become at performing a particular task’. Absent minded errors also tend to manifest during the performance of activities in ‘familiar environments‘ where the practitioner is more liable to be distracted or preoccupied. The technical term for errors that experts are more liable to commit is deformation professionalle. Jonathan Carriere and colleagues also reported an association between depression and a liability to absent mindedness in their paper titled Everyday attention lapses and memory failures: the affective consequences of mindlessness. Other people vulnerable to absent minded slips are those who have a liability to stress.

Older age is another recognised trait that plays a part in error-proneness, and this was explored by Niteesh Choudry and colleagues in their systematic review titled The relationship between clinical experience and quality of health care. They cited evidence to show that ‘there is an inverse relationship between the number of years that a physician has been in practice and the quality of care that the physician provides’. This, they explained, may be due to older doctors possessing ‘less factual knowledge‘, and are ‘less likely to adhere to appropriate standards of care’. They also posit that ‘older physicians seem less likely to adopt newly proven therapies’.

Linda Lee and Wayne Weston also explored this theme in their article titled The aging physician in which they attributed the error-proneness of older doctors partly to cognitive decline. They demonstrated, for example, that ‘adults in their 70s typically take about twice as long to process the same tasks as adults in their 20s‘. They also argued that older physicians rely more often on ‘first impressions‘, and they struggle to generate differential diagnoses, two features that increase the risk of diagnostic error. The authors therefore portrayed experience as a ‘double-edged sword‘ which provides ‘increasingly efficient diagnostic skill involving pattern recognition, countered by age-related decline in analytic reasoning skills’. The authors made several recommendations to improve the quality of older physicians’ care, such as providing ‘longer appointments for patients with complex medical problems’, paying attention to the concerns of others about their performance, and considering reducing or winding down their practice.

The subject of the error-proneness of older physicians was also the focus of a paper by E Patchen Dellinger and colleagues titled The aging physician and the medical profession: a review. The paper highlighted the ‘increasing body of evidence’ linking the age of physicians to their performance‘, and it supports this with statistics to show that ‘between ages 40 and 75 years, the mean cognitive ability declines by more than 20%‘, although this varies between individual physicians. For older physicians therefore, the authors advocated,  ‘cognitive evaluation combined with a confidential, anonymous feedback evaluation by peers and coworkers regarding wellness and competence‘.