by Adam Perkins
The most famous case study of this kind is that of Phineas Gage, a 25-year-old railway construction foreman who was highly regarded for his diligent and polite personality by his employers and also his subordinates. On the afternoon of 13 September 1848, Gage was tamping an explosive charge into a rock that had been drilled for blasting when the charge accidentally exploded, driving the tamping iron (three feet seven inches long and 13 and a quarter pounds in weight with a finely tapered upper end) up through his left cheek and out of the top of his head. Gage was an exceptionally fit young man and was able to walk and talk within minutes of the accident, despite the gaping wounds in the top of his head through which he had lost much of the left prefrontal area of his brain. Despite the severity of this injury, Gage nevertheless made an amazing physical recovery, being pronounced healed within two months of the accident despite losing the sight of his left eye (owing to the path taken through his skull by the tamping iron). His powers of speech and basic intelligence were also unaltered by the accident, yet his personality was changed.
The exact effect of Gage’s brain injury on his personality cannot be quantified precisely, as modern personality questionnaires that formally measure conscientiousness and agreeableness were not available at that time but, by any reasonable analysis, Gage displayed lower levels of conscientiousness and agreeableness relative to his pre-accident self. The most reliable and informative source of first-hand evidence is the account of Gage written in 1868 by his doctor, John Harlow:
The equilibrium or balance, so to speak, between his intellectual faculties and animal propensities, seems to have been destroyed. He is fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires, at times pertinaciously obstinate, yet capricious and vacillating, devising many plans of future operations, which are no sooner arranged than they are abandoned in turn for others appearing more feasible. A child in his intellectual capacity and manifestations, he has the animal passions of a strong man. Previous to his injury, although untrained in the schools, he possessed a well-balanced mind, and was looked upon by those who knew him as a shrewd, smart businessman, very energetic and persistent in executing all his plans of operation. In this regard his mind was radically changed, so decidedly that his friends and acquaintances said he was ‘no longer Gage’.
(Harlow, 1868, p. 277)
The precise details of Gage’s employment history after he left the care of Dr Harlow until his death on 21 May 1860 from a convulsive condition (possibly brought on by his brain injury) are lost, leading to much debate amongst modern scholars over some facts of this case. We do know from Harlow’s records that his employers refused to take him back because of the effects on his personality of his accident. Some accounts suggest he then suffered chronic employment difficulties for the rest of his life, drifting through various basic jobs (including working in a circus freak show; Damasio, 1994). Other accounts suggest that his personality problems gradually subsided after his accident as his brain repaired itself and that he returned to work, earning a living right up until a few months before his death when he began to suffer from increasingly severe convulsions (MacMillan, 2000). We will probably never know for sure what happened, but two photographs of Gage taken after his accident support the idea that he survived reasonably well, as they show a well-built, youthful and healthy-looking man with a handsome face and full, glossy head of hair holding the tamping iron that had injured him, with the only visible sign of the accident being a closed left eye. What we do know for sure is that in the meantime, Gage’s sister had married a wealthy merchant and moved with Gage’s mother to San Francisco. In 1859, Gage moved in with them as his convulsive condition became severe and he died shortly afterwards aged only 38 years old.
The medical significance of Gage’s case at the time was mainly his miraculous survival after such a serious head wound but it also gradually came to be appreciated as important for showing, for the first time, that
there were systems in the human brain dedicated more to reasoning than anything else, and in particular the personal and social dimensions of reasoning. The observance of previously acquired social convention and ethical rules could be lost as a result of brain damage, even when neither basic intellect nor language seemed compromised.
(Damasio, 1994, p. 10)
In support of my hypothesis, Gage’s case tells us an extra thing, namely that an injury-induced reduction in conscientiousness and agreeableness has the knock-on effect of reducing employability, even when physical fitness and intelligence are adequate.
Regardless of the uncertainty surrounding the details of Phineas Gage’s employment record after his accident, this conclusion is backed up by modern studies of patients with damage to the prefrontal area of the brain. In almost all cases, a consequence of this form of brain injury is a drastic decline in the capacity of the patient to hold down a job despite not usually suffering any significant reduction in their intelligence level. For example, one well-documented case study of the effects of prefrontal brain injury is that of Patient A (Brickner, 1932). A 39-year-old stockbroker from New York, Patient A suffered extensive loss of brain tissue in both prefrontal lobes when having a tumour surgically removed. Like Phineas Gage, Patient A showed no loss of intelligence or physical ability following the brain injury but did suffer profound personality change. Before the brain injury, Patient A had been polite, considerate and modest, but afterwards he was highly disagreeable, prone to boastful, cruel and inappropriate behaviour, especially towards his wife, as well as verbal abuse of others when frustrated. His attitude to work was also changed: he lost his drive, spending much time drawing up grandiose plans that he never bothered to implement.
The case of Patient A predates the availability of modern personality questionnaires so it is difficult to quantify exactly the changes to his personality, but based on the descriptions of Brickner (1932), they can plausibly be summarised as a drastic reduction in conscientiousness and agreeableness. The harmful effect of the injury on Patient A’s employability was even more severe than in the case of Phineas Gage, as Patient A never returned to work and spent the rest of his life in the care of his family. This aspect of the case illustrates that patients with prefrontal brain injuries typically show the ‘Phineas Gage Matrix’ of unimpaired intelligence but damaged personality (Damasio, 1994), even if there is usually some variation in outcomes (perhaps reflecting individual differences in the precise site and magnitude of the injury as well as the post-injury care).
This latter point is made clear in a third case study known as ‘Elliot’, who, like Patient A, suffered prefrontal brain damage as a result of a tumour (Damasio, 1994). After the tumour was removed, Elliot also underwent personality changes, but they had a somewhat different quality to those suffered by Phineas Gage and Patient A: whereas these two earlier cases showed a reduction in both conscientiousness and agreeableness, Elliot suffered only a reduction of conscientiousness, being no less agreeable than he had been before his brain injury. For example, prior to the tumour, Elliot was a successful businessman and a caring husband and father, acting as something of a role model for his colleagues and family. After the tumour had been removed, Elliot remained as intelligent, knowledgeable, diplomatic and polite as before, but lost his drive, tenacity and sense of responsible priorities: he needed urging to get out of bed and go to work. At work, Elliot now lacked a sense of overall purpose and would easily be distracted from a task, failing to manage his time properly and deal with interruptions. He would typically spend many hours on one unimportant facet of a task so that the overall aim was neglected.
Nevertheless, in conversation, Elliot remained intelligent, lucid and even charming, an impression backed up by intensive testing which revealed his IQ score to be significantly above average. He was also able to give many sensible answers to hypothetical dilemmas concerning tricky mo
ral or social questions. Despite this impressive level of intellectual functioning and many attempts by colleagues and family to help him, Elliot’s decision-making in real life was flawed and he lost his job. Unable to cope with the change to his personality, Elliot’s wife divorced him, and a second marriage to a woman that all his family and friends regarded as unsuitable did not last long. Ignoring many warnings, Elliot lost his life savings in a manifestly foolish business scheme and ended up relying on welfare benefits.
The interim conclusion at this stage of the chapter is that people who suffer prefrontal brain injury also suffer personality changes that in most cases drastically reduce their employability. Although a personality profile acquired through brain injury will never be exactly comparable to one that arises through natural variation in brain function, these individuals nevertheless display an acquired form of what I have dubbed the ‘employment-resistant’ personality profile, a profile that approximates to low conscientiousness and agreeableness. The next step in my argument is to summarise research that investigated the relationship between personality and employment in families that were dysfunctional and then compared their characteristics to those of functional families in the same neighbourhood. This is important research because if the members of problem families show similar personality profiles to the victims of prefrontal brain injury, we can accept this as further evidence that the employment-resistant personality profile consists of low conscientiousness and agreeableness.
The personality characteristics of problem families
To the best of my knowledge, the most rigorous study of the psychological characteristics of problem families is a two-phase longitudinal research programme that was conducted by W. L. Tonge and colleagues in the English city of Sheffield during the 1970s and 1980s. They aimed to disentangle the effect of psychological factors on social adjustment of families from the effect of socio-economic or geographical influences and then track the effect of those factors in the adult offspring of those families. This study was a rigorous and detailed research programme with many different facets that are of relevance to the theme of this book. I therefore have cited it several times in different chapters, but the relevant results here are to do with personality and employment.
The researchers (Tonge, James & Hillam, 1975) began by profiling 66 families who lived in low-income districts of Sheffield. Half of the sample (33 families) were what we now know as troubled families, but at the time, they were labelled by researchers as ‘problem families’. The problem families were selected because they had sufficient social and occupational maladjustment to be involved with multiple government social-work agencies. The 33 comparison families were selected because they approximately matched the problem families on important variables such as location and income, but nevertheless behaved as relatively solid citizens (at least to the extent that they required intervention from no more than one government social-work agency). In 1981, the accessible adult offspring of the original 66 families were then followed up in order to determine the extent to which maladjustment was transmitted from parents to children (see Tonge et al., 1981 for a summary of phase two).
In phase one of this study, the researchers compared the two groups of families in exhaustive detail, including making comparisons of personality and work records as well as demographic variables such as the number of children in the family. Since modern personality questionnaires that measure personality with five dimensions (extraversion, conscientiousness, agreeableness, neuroticism and openness to experience; Digman, 1990; Costa & McCrae, 1992; Goldberg, 1993) were not available to Tonge and colleagues, they measured personality using a mix of self-report questionnaire and observer ratings. Extraversion was measured by self-report questionnaire (the Eysenck Personality Inventory; Eysenck, 1968) and observer ratings were used to measure impulsivity/irresponsibility, apathy, paranoia and aggression. These latter characteristics were not rated by severity but by frequency of incidents in order to boost consistency between observers. In the technical jargon of modern personality research, impulsivity/irresponsibility and apathy approximate to the low end of the conscientiousness dimension whereas aggression approximates to the low end of the agreeableness dimension.
The personality analysis by Tonge et al. (1975) showed there were no significant differences between the families on extraversion or paranoia, but that the men and women in the problem families were significantly more impulsive/irresponsible, apathetic and aggressive than those in the comparison families. All these attributes are measured by the dimensions of conscientiousness and agreeableness and so this result is consistent with the problem families tending to possess lower levels of conscientiousness and agreeableness than the comparison families.
This finding is important for the present argument because it shows that the personality profile of the problem families only differed from the comparison families on the personality characteristics which other studies give us reason to believe have a particularly strong negative influence on employability and which tend to be deficient in prefrontal brain-injury victims. For example, Tonge et al. (1975) found that 23 of the 30 men in the problem families for which there were assessments displayed at least one incident of impulsive/irresponsible behaviour compared to 5 of the 30 men in the comparison families. Similarly, 17 out of 31 women in the problem families displayed at least one incident of impulsive/irresponsible behaviour compared to 1 of the 30 women in the comparison families. With regard to apathy, 23 of 31 men in the problem families displayed apathy compared to 5 of the 30 men in the comparison families. Tonge et al. also found that 22 out of 30 women in the problem families displayed apathy compared to 3 of the 31 women in the comparison families. With regard to aggression, 13 of the 30 men in the problem families displayed aggressive behaviour compared to 4 of the 30 men in the comparison families. Similarly, 9 out of 31 women in the problem families showed aggression compared to 2 of the 30 women in the comparison families. To give a flavour of the personality survey technique used in this study, an example of an aggressive display was reported in the write-up (it also gives a clear indication of the challenging nature of this type of research): ‘Father very antagonistic. During the visit he stood throwing a flick knife at the kitchen door while telling me he thought I was nosey, interfering and generally “no good”. Clearly, in his mind the kitchen door was me. I was frightened’ (Tonge et al., 1975, pp. 98–99).
If this combination of personality attributes displayed by the problem families represents the employment-resistant personality profile, then problem families should also have had significantly worse work records than the comparison families. And they did: only 9 of the 33 problem families contained parents who had worked for more than 10 per cent of the previous three years, compared to 23 out of 33 of the comparison families. Note that these differences in work record cannot be explained away as a result of the comparison families living in more affluent areas with a more plentiful supply of jobs, as Tonge et al. (1975) took care to make sure that the two groups of families were matched by location. This is important because it fits with the idea that the employment difficulties of the problem families are primarily caused by a lack of motivation to behave conscientiously and agreeably, rather than a lack of job opportunities in the neighbourhood or some other material difference.
Personality and occupational performance
If the neurological case studies and problem family case-control comparisons that I have described are a valid guide, then relatively low levels of conscientiousness and agreeableness should exert similarly harmful, but less extreme effects on the employment records of people who are already in the workforce. Psychologists first began systematic research aimed at revealing the correlates of occupational performance in the early to mid-twentieth century, primarily focusing on studying effects of intelligence. This was as much a practical decision as a theoretical one, since it seemed obvious to them that intelligence should influence job performance and it so happened that reliable and ine
xpensive mass-administration intelligence tests had become available in the 1920s.
This was a result of the pioneering work by Lewis Terman and colleagues during the First World War, who created a paper and pencil IQ test suitable for group administration in order to help the US Army assign soldiers to jobs that suited their abilities. These factors combined to produce hundreds of studies in the subsequent decades that proved general intelligence (often labelled as IQ or ‘g’) is an important determinant of the ‘can do’ or maximal, ability-related aspects of job performance (Schmidt & Hunter, 1998).
However, it has long been suspected that IQ is not the whole story when it comes to the psychological determinants of job performance and that the negative effect of personality deficiencies cannot be compensated for by high intelligence. For example, in 1964, the British industrialist Sir Paul Chambers wrote in Nature magazine that:
Some top-rank public schools and university colleges produce men of brilliant academic achievement who have poor judgement, no power of decision and no capacity to delegate work or to control men. These men can be the tragedies of industry because their deficiencies are not revealed in their academic record and are difficult to detect at a selection interview. They can get started on a promising career, but end in the wilderness of the unpromotable clever boys. On the other hand, the same schools and colleges can produce second-rate graduates who are first-rate men with all the characteristics I have listed.
(Chambers, 1964, p. 227)