by Adam Perkins
As we saw in Chapter 2, some individuals are by chance particularly conscientious and agreeable. With the onset of a stable British society from approximately 1100, Clark suggests that these individuals began to out-compete economically individuals who were prone to impulsivity, selfishness and short-term thinking – what I have dubbed the employment-resistant personality profile. This differed from earlier, more chaotic eras in which it was maladaptive to plan for the future or work cooperatively because, in the absence of a stable society, any economic gains from behaving as a ‘solid citizen’ would easily be stolen or otherwise lost. Under those earlier conditions, Clark plausibly suggests that individuals with personality profiles inclining them to impulsivity, selfishness and short-term thinking would have had the upper hand.
Furthermore, by surveying a variety of relevant historical records such as wills and testaments, Clark found that economic success that highly conscientious and agreeable British people experienced between about 1100 and 1800 translated into greater reproductive success: the least economically successful people commonly raised no children at all and citizens of average income raised half the number of children compared to the most economically successful. Because the children of the economic elite tended to share, through both cultural and genetic inheritance, the diligent, cooperative personality profiles that had sprung their parents to success, solid citizen personality characteristics began to proliferate.
But, according to Clark, there weren’t enough occupational niches at the top of society for all of the offspring of the economic elite, with the result that many of them filtered down to progressively more ordinary occupations. Clark calls this phenomenon downward mobility, with, for example, the offspring of wealthy landowners becoming farmers, their offspring becoming shopkeepers or teachers, their offspring becoming farm labourers and so on. Since these downwardly mobile offspring of the economic elite tended to bring with them to these lowly jobs the same pro-employment personality characteristics that had caused the success of their ancestors, these economically beneficial attributes became increasingly common and thus boosted the overall economic effectiveness of society.
Eventually, by around the year 1800, Clark claims that this process triggered an economic and technological leap so enormous and rapid, namely the Industrial Revolution, that it allowed Britain to be the first country to escape the Malthusian trap. Other countries with similar geo-political conditions to Britain followed suit rapidly, so giving rise to the modern, developed world that we know today. Crucially, Clark argues that, in parts of the globe with less stable geo-political conditions, this personality moulding process favouring conscientiousness and agreeableness has not occurred and so attempts to impose Western-style industrialisation from outside have generally seen little success because the average personality profile of the population remains in a more employment-resistant state, similar to the personality profile of Dark Age Britons. More briefly stated, unless the solid citizen personality profile is prevalent in the population, the seeds of industrialisation tend to fall on stony ground.
For readers unfamiliar with the economic literature, the Malthusian-trap concept explains why human societies up until the Industrial Revolution stagnated economically and could not significantly increase their income. According to Clark’s theory, the prevailing employment-resistant personality profile of the population meant that the population in general was unable to work efficiently enough to develop new technology at anything other than a slow rate, so slow that it only ever boosted the efficiency of production by a small amount and the resultant population increase consumed the surplus. Average income then fell back to its former level, leaving our ancestors trapped in a grim cycle of tiny improvements in living standards followed by a rapid return to filth and squalor, fighting in the mud for a less damp piece of sackcloth or a less mouldy piece of turnip.
Viewed through the lens of personality research, Clark’s findings mean that the pro-employment personality characteristics that are supposedly standard issue in the members of modern British society (for example, turning up on time for appointments, working hard, doing what we are told, cooperating with our peers, looking after the weak, believing that one good turn deserves another) are by no means part of the typical human behavioural repertoire, but instead were moulded by natural selection in response to the peculiar environmental circumstances in the UK from about 1100 onwards that allowed particularly conscientious and agreeable people to prosper. Conversely, if circumstances change and employment-resistant individuals gain the reproductive upper hand – as I argue is happening due to the welfare state – then it is likely that the average personality profile of the population will swing back towards impulsivity, selfishness and short-term thinking with all the concomitant societal problems that will bring.
Personality and reproduction in the modern era
If it is true that the welfare state boosts the capacity of employment-resistant individuals to act upon their predisposition to r selection, we should find that, following the advent of the welfare state from the mid-twentieth century, there is an increasing tendency for the employment-resistant personality profile to be associated with relatively high rates of reproduction. Ideally, we should test this idea via longitudinal data, in which personality is measured in childhood and then compared to the total number of children that the participants have as adults. We saw in Chapter 3 that the Dunedin Study showed that childhood self-control is a proxy measure of employment-resistant personality characteristics: the lower the score on childhood self-control, the worse the individual tends to do in the world of work when they reach adulthood (Moffitt et al., 2011). We should therefore see evidence that relatively low levels of childhood self-control are associated with having relatively large numbers of children and that this tendency should become more pronounced in later cohorts as the welfare state becomes ever more entrenched in the culture of the nation.
In the UK there are two large cohort studies that are suitable for testing this idea since they both measured self-control in childhood and number of children, but crucially, the cohorts are separated by 12 years, meaning that they can be used to track changes over time in the link between personality and reproduction. In line with the notion that employment-resistant personality characteristics predispose individuals to having lots of children, both cohorts show a tendency for low levels of childhood self-control to be associated with having large numbers of children. But it is the increase over time of this effect that is important to the topic of this book. First, the National Child Development Study (NCDS) is following participants from their birth in one week in 1958, with the last survey point being at the age of 55 (7,219 participants provided full data). As can be seen in Figure 4.3, NCDS participants with five or more children scored on average 6 per cent lower on childhood self-control than participants with no children did.
Similarly, the British Cohort Study (BCS) follows participants from their birth in one week in 1970, with the most recent survey point being at the age of 42 (7,046 participants provided full data). Figure 4.4 shows that BCS participants with five or more children scored on average 15 per cent lower on childhood self-control than participants with no children did. This represents a doubling, in just 12 years, of the strength of the association between low scores on childhood self-control and having large numbers of children as an adult.
Figure 4.3 Childhood self-control and reproduction in a British cohort born in 1958
Source: National child development study.
Figure 4.4 Childhood self-control and reproduction in a British cohort born in 1970
Source: British Cohort Study.
Viewed as a whole, the results of these two cohort studies – since they are 12 years apart, yet in the same nation – suggest that as the welfare state has become more entrenched in Britain, there has been a strengthening of the tendency for employment-resistant individuals to have large numbers of children. This finding could be a coincidence, but it is what we w
ould expect to see if the welfare trait theory is correct. However, even if the finding is valid, both these cohort studies are based in the UK. It is therefore desirable to survey associations between personality and reproduction in other advanced nations that possess a welfare state in order to verify that this pattern generalises across nations and is not specific to British culture.
The study of personality and reproduction in humans is in its infancy but five studies have measured associations between number of offspring and personality questionnaire scores in advanced nations other than the UK. They can therefore provide some relevant insights into the topic. Three of these five studies support the notion that the reproductive fitness of the employment-resistant personality profile has changed since the era studied by Professor Clark, by finding that conscientiousness-domain scores were negatively correlated with reproduction. Jokela, Hintsa, Hintsanen and Keltikangas-Järvinen (2010) found that having more children was associated with low scores on persistence in 1,535 Finns. Similarly, in a sample of 8,373 US women, scores on conscientiousness were negatively associated with offspring number independent of educational level and parental SES (Jokela et al., 2011).
I have explored, with several colleagues, associations between reproduction and personality questionnaire scores in 4,981 women from four Australian samples. In two out of four of these samples, we found there were small but significant negative associations between reproductive fitness and personality measures in the conscientiousness domain (Perkins et al., 2013). In contrast, two other studies tell an opposite story, showing that reproductive fitness was positively correlated with social responsibility in 99 US women (Bogg & Roberts, 2004) and with conscientiousness in 2,900 Dutch women (Dijkstra & Barelds, 2009).
On balance therefore, the majority of these studies are consistent with the idea of a positive association in present-day developed nations between the employment-resistant personality profile and the tendency to have many children, but correlation does not necessarily indicate causation. In order to gain a more informative picture of the relationship between personality and reproduction, we require a study that measured the change in associations between personality and reproduction in different birth cohorts spanning pre-welfare state eras up to modern times.
Fortunately, another study by Jokela (2012) provides just such an analysis. This study used two major surveys that contained personality questionnaire scores and reproduction data in 10,253 US citizens with birth years that ranged from 1914 to 1970 (some of the same participants were studied in Jokela et al., 2011, so this study is not wholly separate from that one). Nevertheless, because it spanned successive birth cohorts, this follow-up study was able to reveal changes in personality–reproduction associations over time, showing that in women born in the 1910s and 1920s, reproductive fitness and conscientiousness were unrelated, but the negative association seen in modern studies emerged with increasing strength up to the final cohort of women who were born in the 1960s and 1970s.
Jokela (2012) hypothesised that this change is caused by the emancipation of the female labour force that began in the early part of the twentieth century which may have encouraged highly conscientious women to limit reproduction in order to build their careers. These data also fit the theory that the advent of the welfare state from the mid-twentieth century onwards may have progressively buffered the reproductive disadvantage of economic failure associated with low conscientiousness that, according to Greg Clark (2007), existed in pre-welfare eras.
Surveys by questionnaire of the type described above suffer from the limitation that they are voluntary and confer no material gain on the participant. It is therefore plausible that they reduce the effects of personality on reproduction, as they are more likely to be completed by citizens with relatively more conscientiousness and agreeable personalities, but miss data concerning people with the opposite personality profile, namely the employment-resistant personality profile that is the focus of this book. For this reason, it is valuable to turn to relevant data that are gathered under different circumstances, namely those where it is in the self-interest of the participant to complete the survey.
The second study in my publication that I reference above (Perkins et al., 2013) attempted to address exactly this question, since it used data from the Vietnam Experience Study (VES; US Department of Health & Centers for Disease Control, 1989) that gets round this problem of altruism skewing the results since participation in the study benefitted the participants. The reason for this was that the VES was initiated in response to growing public concerns in the 1970s and 1980s that the herbicide Agent Orange, which had been used in an attempt to make the location of communist forces easier by defoliating jungle in Vietnam, had damaged the health of US servicemen there.
The VES therefore compared the physical and mental health of US Army veterans who had served in Vietnam between 1965 and 1971 with that of veterans who had served during that same time period in territories where Agent Orange was not used (for example, Korea, Germany or the USA). A prominent concern relating to the use of Agent Orange during the Vietnam War was that it may have made the servicemen who were exposed to it less fertile. The VES therefore recorded offspring numbers. In addition, military discharge status and employment history after leaving the military were available for all participating veterans, making the cohort useful for the present research on the basis that participants with an employment-resistant personality profile would be less likely than average to receive an honourable discharge, and would go on to have a less satisfactory employment record. A key aspect of this data set was that failing to achieve an honourable discharge was rare. The vast majority of servicemen were honourably discharged (96.1 per cent), meaning that the non-honourably discharged servicemen can plausibly be seen as representing the extreme low end of the spectrum of employability rather than some slight tendency to be unreliable or difficult.
What we found was a pattern of results that supported the notion that the employment-resistant personality is associated with rapid, irresponsible reproduction. On average, honourably discharged servicemen fathered significantly fewer children than non-honourably discharged servicemen (1.79 children versus 1.98 children). The notion that the latter group of servicemen possessed an employment-resistant personality profile was backed up by the finding that despite around 15 years elapsing between leaving the military and being interviewed for the VES, in the three years before interview, the non-honourably discharged servicemen experienced an average of three times greater duration of unemployment compared to the honourably discharged servicemen (10.01 months unemployment versus 3.73 months). We went on to conclude that
Since this finding persisted even when controlling for individual differences in cognitive ability, it points to an irresponsible personality profile amongst the non-honourably discharged men as, despite their seemingly chronic difficulty in holding down a job, the non-honourably discharged men nevertheless went ahead and fathered more children than the occupationally more successful honourably discharged men.
(Perkins et al., 2013, p. 875)
This result fits the previous finding by Figueredo et al. (2006) that an r-selected reproductive strategy (rapid, irresponsible reproduction) is favoured by people with a personality profile that corresponds to my concept of employment-resistance. Moreover, although the VES did not include modern questionnaire measures of personality, it did obtain scores on the Minnesota Multiphasic Personality Inventory (MMPI-1; Hathaway & McKinley, 1940) for the subset of 4,459 participants who attended clinics to be studied in more detail for the VES. The MMPI questionnaire measures personality via ten clinical criterion-keyed scales that do not match the five-factor structure used in most modern personality questionnaires. Nevertheless, since it is plausible that clinical personality dysfunction will reduce employability, these MMPI data were examined with a view to providing a general assessment of whether men who failed to achieve an honourable discharge from the military had divergent personality traits in
comparison to honourably discharged men.
In the 4,459 men in the VES with MMPI scores, those who were not honourably discharged scored significantly higher on seven out of the ten MMPI scales, most notably on the psychopathic deviate scale. This finding is important because the antisocial aspects of the employment-resistant personality profile mean it can be viewed as a mild form of antisocial personality disorder or psychopathy. This notion is backed up by the finding that individuals who have antisocial personality disorder are relatively lacking in both conscientiousness and agreeableness (for example, Lynam et al., 2005). It is further supported by our finding that servicemen who were not honourably discharged not only scored higher on psychopathic deviancy, but also had worse work records after leaving the military than those who were honourably discharged (Perkins et al., 2013).
Welfare and reproduction
The studies I have just summarised indicate that in the modern era, the employment-resistant personality profile is associated with having more children. This contrasts with pre-welfare eras when people who were economically unsuccessful – and thus presumably less conscientious and agreeable – tended to raise fewer children than average citizens (Clark, 2007). Since we already know that people with employment-resistant personalities are over-represented in the welfare-claiming sector of the population (Vaughn et al., 2010), this analysis suggests that we should see evidence that welfare claimants, on average, have more children than employed citizens. And we do.
For example, Table 4.1 summarises statistics on reproduction and employment in England and Wales for April–June 2013. These have the merit of measuring reproduction in three levels of reliance upon the welfare state: (a) working households, where every 16–64-year-old is employed; (b) mixed households, which contain both employed and unemployed adults; and (c) workless households, where all 16–64-year-olds are unemployed. This three-level measurement strategy shows that there is a positive linear association between reliance on the welfare state and average levels of reproduction in England and Wales: the higher the proportion of unemployed adults in a household, the greater the number of children (on average) that it contains. The implication contained in the data summarised in Table 4.1 is that a welfare state which provides a significant boost to household income for every child born is capable of boosting reproduction amongst claimants to a level higher than that of employed citizens.