Fluid and Crystalized in Intelligence in Older Age

When refer to “fluid” and “crystallized” intelligence of older adults we are still using 1950s constructs. Constructs that are antiquated, eugenic constructs.  Rarely do we see such references for younger people. There is not one article reporting that younger people’s crystalized intelligence is immature. But somehow these construct explain older adults diminished capacity for intelligence. By looking deeper into the use of these indicators of intelligence shows a glaring ageist perspective. 

The Cattell-Horn Theory of Fluid and Crystallized Intelligence has been a resilient theory in psychology for more than 50 years, especially when referring to older adults. First proposed by the British psychologist Raymond Bernard Cattell in 1941 and later much refined with his student John L. Horn in 1964, Cattell believed that intelligence was a genetic attribute. He held eugenicist views that race played a major part in determining our intelligence. In line with the time, he also saw aging as a period of loss and decline.

Although Cattell is also credited with developing an influential theory of personality--16 personality factor model of personality--and creating new methods for statistical analysis--multivariate analyses, and with Charles Spearman developed Factor Analysis--his lasting legacy has been the proposal that intelligence is a reflection of some 100 discrete abilities which can be categorized broadly into two different sets of abilities: Fluid and Crystalized intelligence.  These abilities have quite different trajectories over the course of development from childhood through adulthood. While Crystallized intelligence continues to incremental improve, Fluid intelligence peaks at around 20 years of age and then declines slowly by age 65.

Table: Fluid and Crystalized Intelligence across the Lifespan

(from Baltes P B, Lindenberger U, Staudinger U M, 1998)

Fluid intelligence is one of the discrete factors of general intelligence, proposed to be an innate and inherent learning capacity of all individuals. Fluid intelligence is independent of one’s education, learning and experience and reflects an individual’s natural mental ability. This is your “smarts.”  Such capacity also includes your capacity for learning, problem solving and pattern recognition. Fluid intelligence is thinking on your feet…this is what Piaget refers to as “Intelligence is what you use when you don't know what to do.”

Crystallized intelligence on the other hand is the more stable memory-based intelligence. It is the accumulation of expertise through learning and skill development. It can be manipulated, mimicked. These are things that you ‘know.’ As such they are seen as a repository of clever things.

Initially there was much talk of specific areas of the brain responsible for each individual aspect of intelligence. However, the distinction between the two types of intelligence is not in brain structures. In 2014, Aron K. Barbey and his colleagues with the University of Illinois studied 158 human brain lesions of male patients who had an average age of 58, to investigate the neural foundations of key competencies for fluid intelligence and working memory. Although they found that both type of cognitive activities are active in the fronto-parietal network—a region of the brain on the top of the head above the ears—there were distinct patterns of activation for fluid intelligence and what they call working memory (crystalized intelligence).

However, none of these studies tested older adults or women. More importantly they have no predictive quality. Knowing which part of the brain is active most, does not inform you what the person is thinking. There might be distinct areas of the brain becoming more active depending on the type of task being performed rather than the type of thinking being used.  It is likely that there are no distinct types of intelligence. It is also likely that only distinct tests we use to measure intelligence can be distinguished under two general types and that there are no distinct intelligence. There are also no different areas of the brain used for different types of intelligence. It could be that different tasks might use a part of the brain more than others. The variability among people is also under-reported. What might be activated in your brain might be different from how my brain reacts to the same task.   This criticism is not to discount the value of doing fMRI studies, but to calm the generalization from these studies. The impression given is that there are distinct types of intelligence that use distinct areas of the brain. The corollary of this is that with aging brains we will see diminished capacity in some type of intelligence related to that part of the diminished brain. But this is not the case.  To understand why this is not the case we have to go back to the beginning and explore how Cattell defined the two sets of intelligence in the first place.

The 1950s was a great time for psychology. While psychiatry was moving towards biology, pharmacology and brain surgery—using such barbaric but seemingly efficacious techniques such as prefrontal lobotomy, insulin shock therapy, and ECT; and while psychoanalyses shed its Freudian skin and was moving towards behavioral and cognitive therapy (later to morph into humanistic therapy); Psychology was being engulfed by the behaviorists and the emergence of statistics as the method of choice. The belief was that the human mind is a black box that we can never know. But through scientific rigor and with enough experimentation and statistical strength we can predict--but not understand--the black box. This was Cattell’s world. With sheer statistical strength we can force through a predictive model of the brain.

Using over 100 discrete tests for intelligence, Cattell put them all in a statistical hopper, shook them up, and saw which ones relate to each other. Using this method of defining clusters--called Factor Analysis--he defined two main groupings which he later called Fluid and Crystalized Intelligence. The clusters relate to the tests used, not to some innate distinction of intelligence. The expectation is that the breadth of the test used somehow represents the full capacity of our intelligence. By today’s standards, this assumption will be considered fanciful.

Once in the statistical hopper, how you determine what unique entities are related, and what unique entities are not related is by looking at their statistical loadings--how much they correlate with each other. If one test score is consistently high while another one is consistently low, then the analysis separates them as distinct. While if two test scores mirror each other, while one goes up the other goes up and then when one goes down the other goes down, then the two tests are related. Although this seems logical, in reality there are no real cut off point in their loading factors. How high and how low is determined not by the statistical analysis but by the researcher. Human judgement make that determination at what loading each variable is considered “in” or “out” of the Factor.

Recent work by the now deceased German gerontologist Paul Baltes and his colleagues demonstrated that older adults benefit markedly from guided practice in cognitive skills and problem-solving strategies. By focusing on the fluid ability, a small sample of 72 healthy older adults were capable of improving their fluid intelligence. They expressed improvement both by themselves and by following tutor-guided training. The ability to improve one’s fluid intelligence is not innate but a function of utility. Use it or lose it.

Practically, if older adults are shown to have an increasing capacity for crystalized intelligence then their need to use fluid intelligence diminishes. It is not that the ability diminishes, it is that their expertise in crystalized intelligence make reliance on fluid intelligence less essential. There are fewer opportunities to “wing it” when you know the outcome. The ageist view that somehow an aging brain losses its capacity for one of the most unknown features of intelligence—fluid intelligence, that capacity to create connections--reflects a shadow of the old eugenicists view that also denigrated older adults as diminished beings. Using these two concepts of Fluid and Crystalized Intelligence do not hold predictive power, and are useless in a clinical setting. It is time to remove the shackles of old eugenics legacy and stop using this ageist construct. Perhaps we can invest in research that starts to admire the model of reality that older people have created in their brain.

References

Cattell, R.B. (1941). Some theoretical issues in adult intelligence testng. Psychological Bulletin, 38, 592.

Barbey, A. K., Colom, R., Paul, E. J., & Grafman, J. (2014). Architecture of fluid intelligence and working memory revealed by lesion mapping. Brain Structure and Function, 219(2), 485-494.

Baltes P B, Lindenberger U, Staudinger U M (1998) Life-span theory in developmental psychology. In: Lerner R M (ed.) Handbook of Child Psychology: Vol. 1. Theoretical Models of Human DeŠelopment, 5th edn. Wiley, New York, pp. 1029–143

Baltes, P. B., Sowarka, D., & Kliegl, R. (1989). Cognitive training research on fluid intelligence

in old age: what can older adults achieve by themselves?. Psychology and aging, 4(2), 217.

Horn, J.L. (1965). Fluid and crystallized intelligence: A factor analytic study of the structure among primary mental abilities. Ph.D. Thesis. University of Illinois.

© USA Copyrighted 2016 Mario D. Garrett

Suicide among Older Adults: Not all in the head

Why are suicide rates going up after a decline in the 1980s? Why do people feel that death is a better option than staying alive? Suicide seems to be like politics. We have simple and terminal solutions to very complex and nuanced problems. Just like in politics, we keep making the same mistake by treating suicide as one problem rather than an expression of a dynamic interaction between the individual and their environment. We have been trying to change the individual without treating the environment.

Suicide is an unspoken pandemic—where every country in the world experiences it in silence.  Unspoken and shamed despite the fact that worldwide, every year, over one million people die by suicide. Suicide accounts for around one in every 50 deaths. On average, for every 100,000 people, 16 will kill themselves. But there is tremendous variation. Generalities hide the raw reality of suicide.

Suicide rate varies by country, income, gender, age, time period and ethnicity. These factors all play a major role. Because countries that top the suicide rates are so diverse, it seems to be an erratic malady. Countries with the highest suicide include: Guyana in South America, followed by countries of Eastern Europe, Japan, South Korea, and Europe— with Belgium leading the continent.  The USA lies 50th in a list of 170 countries.

What is perplexing and worrying is that international suicide statistics report that rates have increased by 60% in the past 45 years, in particular since the 1980s. It is not that we are entering a new dystopian world, but that we have erased the progress we made before. In 2013, in the United States, the highest suicide rate was among people 45 to 64 years old, when an estimated 10,189 older Americans committed suicide (particularly White men). Nearly one in five suicides were among the middle-aged, but this was closely followed among those 85 years and older. In fact, the rate of suicide in the oldest group of white men (ages 85+) is over four times higher than the nation’s overall rate of suicide.  In the United States, while there was a decrease for both men and women aged 75 and over in 2014, suicide among adolescents and young adults continued to increase.

There are many ways to kill yourself, but the one that is gaining popularity, for both females and males, is suffocation. This includes hanging, strangulation, and putting a plastic bag over your head, sometimes with a gas such as helium.  In the USA suffocation ended one in four suicides in 2014. However, the most common methods of suicide differed for men and women.  In the USA--where we have over 300 million guns--more than half of male suicides were caused by firearms, a statistic other countries do not share. While for women, who are less likely to have access to guns, poisoning was the most common method. Poisoning includes taking pills. Additionally, females were likely to jump or drown, and men were likely to jump to their death or cut themselves with knives (less than 1 in 20 suicides for both gender).

Although men 75 and older have the highest rate of suicide, for women the highest rate is for middle age 45-64 followed by 25-44 and 65-74 age groups. Therefor men and women must have different triggers.  For women, the spur seems to be spread across a broader age group, yet the triggers for men seem to be concentrated in older age. For men this finding has been explained as a loss of work identification, declining health and virility, and a whole list of negative events that older men are prone to. Is it the loss of income earning, that for the first time they are no longer the bread winners?

It is only by bringing more information together that a picture emerges revealing a silent story, something that individual numbers by themselves cannot express. In 2012, Clare Wyllie and her colleagues in a study for the Samaritans in the United Kingdom reported that poorer middle-aged men are more likely to commit suicide than men with higher incomes. And this is not a solitary finding. A recent study in Greece, by George Rachiotis and his colleagues with the University of Thessaly, Larissa, Greece, found clear increase in suicides among persons of working age coinciding with poverty, suggesting that suicide risk in Greece is a health hazard associated with austerity measures. In addition to poverty, other factors that promoted suicide were relationship breakdown, isolation and mental health problems. All of these are inter-related. The causes of suicide are numerous and connected together. A quick review of suicide studies will dispel the idea of a quick fix since there are many factors that can act as triggers. How these triggers work have been a source of confrontation between academicians and clinical staff.  Although intuitively we might accept that suicide is not just a medical issue, our treatment of it remains purely clinical--medical and behavioral. Pushing back against this attitude is not new.

The first academic study of suicide did just that. Written by the father of Sociology, Emile Durkheim, in 1897 Suicide, transformed how we look at this problem. While psychiatrists at the time were searching for the biology of disease, Durkheim noticed that stronger social control among Catholics resulted in lower suicide rates. He highlighted that there are social factors that determine the expression of suicide. Although Durkheim’s method was flawed--termed as an Ecological Fallacy; surmising an individual’s traits from generalized statistics—he was accurate in assigning a social aspect to suicide.

Durkheim saw suicide as a normal reaction to a unique feeling of detachment from society. As such he saw a social component, especially since suicide varies by country and that these social factors must be intrinsic to the country. Durkheim argues that when social conditions fail to provide for people’s expectations, the most vulnerable react by the only means they know of stopping the pain. In line with such a sociological perspective, Ben Fincham a sociologist with the University of Sussex, has argued that the question is not why people commit suicide but he asks what social factors “contribute to people feeling as though they wish to die.”

Suicide is seen as a failure. A failure on the part of the individual who commits or attempts suicide by not being strong enough to overcome difficulties; Failure on the part of family and parents for a perceived lack of insight; Spouses feel that the suicide is a reflection of their lack of engagement in the relationship; Communities respond with shame that it happened among them; and society looks at suicide as a rejection of their way of life. But the real failure lies in how clinical and social services deal with suicide. There are nuances to suicide that we are ignoring.

For every successful suicide there are many failed attempts. In most cases there are enough warning signs. Although men are four times more likely to commit suicide then women, women attempt suicide three times more often than men.  Attempted suicide varies considerably by age as well. It seems that becoming older makes you more adept at carrying out an effective suicide. For every young person that commits suicide there are 25 attempts, while for older adults four attempted suicides results in one death. As a result, there are fewer opportunities to intervene with suicide among older adults. In 2000, Ulla Agerskov Andersen and her colleagues with the University of Southern Denmark, repeated the findings that suicide victims are falling through our safety net to their death. The authors reported that just under half of the victims had been hospitalized in psychiatric departments beforehand, one in seven within the last month. Two out of three of the victims consulted with their primary care physician within the last month before killing themselves. There is ample supporting evidence for this behavior. There are muted last pleas for help.

Until we appreciate that suicide is an expression of more than a mental illness and involves a perceived negative environment, only then can we look at both sides of these triggers. The fact that vulnerable adults express silent pleas for help beforehand needs to be the call to action for clinical and social services. The missing aspect, especially in research, is the lack of examination of how their environment can be changed to minimize the likelihood of using suicide as their exit strategy. There are other options for reducing the pain and it’s not all in the head.

Further reading:

·      Andersen, U. A., Andersen, M., Rosholm, J. U., & Gram, L. F. (2000). Contacts to the health care system prior to suicide: a comprehensive analysis using registers for general and psychiatric hospital admissions, contacts to general practitioners and practising specialists and drug prescriptions. Acta Psychiatrica Scandinavica, 102(2), 126-134.

·      Pirkis, J., & Burgess, P. (1998). Suicide and recency of health care contacts. A systematic review. The British Journal of Psychiatry, 173(6), 462-474.

·      Luoma, J. B., Martin, C. E., & Pearson, J. L. (2002). Contact with mental health and primary care providers before suicide: a review of the evidence.American Journal of Psychiatry, 159(6), 909-916.

·      Isometsa, E. T., Heikkinen, M. E., Marttunen, M. J., Henriksson, M. M., Aro, H. M., & Lonnqvist, J. K. (1995). The last appointment before suicide: is suicide intent communicated?. American Journal of Psychiatry, 152(6), 919-922.

·      Vassilas, C. A., & Morgan, H. G. (1993). General practitioners' contact with victims of suicide. BMJ: British Medical Journal, 307(6899), 300.

© USA Copyrighted 2016 Mario D. Garrett