Psychology of Aging

Aimee Spector, Martin Orrell

• Publisher: Routledge
• Year: 2017
• Print ISBN:
  9780754627890
• eBook ISBN:
  9781351907842
• Topic: Psychology
• Subtopic: History & Theory in Psychology
• Index: Psychology

The psychology of aging is an exciting and rapidly-developing field. This volume provides a collection of classic, original and often widely-cited papers, including some older papers which may be hard to find through conventional searches. Taken together, they help to address some key questions: what are the cognitive changes related to aging? Is mental exercise useful? To what extent might intelligence, education or stimulating mental activities delay or even reduce cognitive symptoms of dementia? However, the book goes well beyond cognition and addresses social and emotional changes in aging, as well as looking at how lifestyle factors may be influential in psychological functioning. The section on the psychology of dementia covers the evolving psychological models, plus innovative types of psychological interventions. As more people live to an age where they are dependent on others, the book also considers the stresses on carers and how carers can be supported. Lastly, other aspects of mental health problems in old-age are addressed, including depression, PTSD and personality disorder. This collection of intriguing and inspiring papers will liven up the shelves of students, researchers and academics in the field as well as being a very useful resource for research, teaching and study.

Part I
Cognition and Aging

[1]
The Stability of Individual Differences in Mental Ability from Childhood to Old Age: Follow-up of the 1932 Scottish Mental Survey

IAN J. DEARY

University of Edinburgh, Edinburgh, Scotland, UK

LAWRENCE J. WHALLEY
HELEN LEMMON
J.R. CRAWFORD

University of Aberdeen, Aberdeen, Scotland, UK

JOHN M. STARR

Royal Victoria Hospital, Edinburgh, Scotland, UK

All Scottish children born in 1921 and attending school on June 1, 1932 (N = 87,498) undertook a validated test of psychometric intelligence, The Moray House Test. We followed up 101 of these people at age 77 and re-administered the same mental ability test. Concurrent validity data are provided for the Moray House Test at age 11 (n = 1,000) and age 77 years (n = 97). The correlation between Moray House Test scores at age 11 and age 77 was 0.63, which adjusted to 0.73 when corrected for attenuation of ability range within the re-tested sample. This, the longest follow-up study of psychometric intelligence reported to date, shows that mental ability differences show substantial stability from childhood to late life.

Introduction

The stability of individual differences in human mental abilities is of scientific and popular interest (Jensen, 1980). In childhood, it is of interest to discover whether educational initiatives can boost ability levels and whether environmental insults—such as poor nutrition or lead pollution—can lower cognitive functions. In old age, there is intense interest in whether mental ability differences earlier in life contribute to the risk of dementia and other syndromes of cognitive decline (Snowdon et al., 1996).

Table 1. Summary of Some Key Studies of the Stability of Individual Differences in Psychometric Intelligence

Study	Mean initial age (years)	Mean follow-up age	Correlation	Test used
Humphreys (1989)	2	9	0.56	Wechsler Preschool and Primary Scale of Intelligence and Wechsler Intelligence Scale for Children
	9	15	0.47
	2	15	0.78
Kangas and Bradway (1971)	4	42	0.41	Stanford – Binet
	14	42	0.68
	30	42	0.77
Eichorn et al. (1981)	17–18	36–48	0.83 (men), 0.77 (women)	Stanford-Binet or Wechlser Bellevue (initial) and Wechsler Adult Intelligence Scale (follow-up)
Plassman et al. (1995)	Approx. 18	Mid-60s	0.46	Army General Classification Test (initial) and Telephone Interview for Cognitive Status (follow-up)
Owens (1966)	19	50	0.79	Army Alpha
	50	61	0.92
	19	61	0.78
Nisbet (1957)	22	47	0.48	Simplex Group Test
Schwartzman et al. (1987)	25	65	0.78	Revised Examination “M”
Tuddenham etal. (1968)	30^a	43	0.64–0.79	Army General Classification Test
Mortensen and Kleven (1993)	50	60	0.94	Wechsler Adult Intelligence Scale
	60	70	0.91
	50	70	0.90
Deary et al. (present study)	11	77	0.63	Moray House Test

^a Subjects were probably 7 years younger than this making the follow-up interval 20 rather than 13 years.

There are reports of the stability of measures of mental ability: (a) within childhood (Humphreys, 1989); (b) from childhood to mid-adulthood (Kangas & Bradway, 1971); (c) across young- to mid-adulthood (Eichorn, Hunt, & Honzik, 1981; Nisbet, 1957; Owens, 1966; Plassman et al., 1995; Schwartzman, Gold, Andres, Arbuckle, & Chaikelson, 1987; Tuddenham, Blumenkrantz, & Wilkin, 1968); and (d) in old age (Mortensen & Kleven, 1993). Table 1 summarizes these studies, showing the duration across which stability of individual differences was assessed and the stability coefficients obtained. The studies collected in Table 1 show that intellectual ability differences become increasingly stable throughout childhood, and have high stability across many years of adulthood. Both the Concordia study (Schwartzman et al., 1987) and the Intergenerational Studies (Eichorn et al., 1981) found higher stability across adulthood for verbal abilities than for non-verbal/performance IQ-type abilities.

The value of knowing the stability of mental ability differences from early adulthood to old age was emphasized in two long-term follow-up studies. In the “Nun Study,” the linguistic complexity of hand-written autobiographies in early adulthood correlated with the incidence of dementia and mental ability level in late life (Snowdon et al., 1996). In a separate study, recruits from the American armed forces in the early 1940s were administered the Army General Classification Test and followed up 50 years later using a brief telephone-administered cognitive interview (Plassman et al., 1995). This latter study made particular mention of the necessity yet rarity of having early life cognitive estimates in the interpretation of cognitive scores in old age. Therefore, though it is a research priority, we do not know the stability of psychometric intelligence differences from early to late life. The principal reason for this gap in our knowledge is the rarity of samples of the population who were tested in youth and then followed up in old age.

We now report the first follow-up study of human cognitive ability that extends from childhood (mean age 11 years) to old age (mean age 77 years), and is thus informative about the stability of mental functions across most of the human lifespan. Further improvements upon the best currently available studies (Plassman et al., 1995; Schwartzman et al., 1987; Snowdon et al., 1996) include: (i) the use of the same validated mental test at baseline and follow-up using identical instructions; (ii) characterization of the follow-up sample in terms of age, sex, and initial IQ with respect to the entire relevant Scottish population; and (iii) concurrent validation of the mental test at first testing (age 11 years) and follow-up (age 77).

Background to the Present Study

We used data from the 1932 Scottish Mental Survey to investigate the stability of psychometric intelligence differences across a gap of 66 years. The Scottish Mental Survey 1932, under the auspices of the Scottish Council for Research in Education (SCRE), sought to quantify the number of people in Scotland who were “mentally deficient.” It was broadened to “obtain data about the whole distribution of the intelligence of Scottish pupils from one end of the scale to the other” (Scottish Council for Research in Education, 1933). On June 1, 1932, all children at school in Scotland and born in the calendar year 1921 undertook a group-administered mental ability test, including some practice items. Children were tested in classrooms by teachers who followed detailed printed instructions. The number of children tested was 87,498 (44,210 boys and 43,288 girls). A very small number of private schools and those children absent owing to sickness were the only 1921-born children not tested.

The group mental ability test used in the Survey is referred to in the original publication as the “Verbal Test” (Scottish for Council for Research in Education, 1933). The test comprises a variety of types of item as follows: following directions (14 items), same-opposites (11), word classification (10), analogies (8), practical items (6), reasoning (5), proverbs (4), arithmetic (4), spatial items (4), mixed sentences (3), cypher decoding (2), and other items (4). The test has 71 numbered items, 75 items in total, and the maximum possible score is 76. The test was closely related to the Moray House Test No. 12, which was used in “eleven-plus” examinations in England. We shall hereafter refer to the test as the Moray House Test. The scores on the Moray House Test in 1932 were validated by individually re-testing a representative sample of 1,000 of the children (500 boys, 500 girls) on the Stanford Revision of the Binet-Simon scale. Those who administered the individual Stanford-Binet tests had special training in mental testing.

Method

Subjects

The Scottish Council for Research in Education made the complete data set for the 1932 Scottish Mental Survey available to the authors. From January to May 1998, we traced local (North-East Scotland) survivors of the 1932 Scottish Mental Survey. With the approval of the Grampian Ethics of Research Committee and family doctors, we contacted 199 survivors randomly selected from the Community Health Index (the local register of people’s allocations to family physicians in the UK’s National Health Service) and 35 other locals who volunteered on hearing media reports of the study. Of the 234 potential subjects, 208 people agreed to a full physical and mental health assessment and 73 agreed, in addition to the aforementioned health checks, to re-take the Moray House Test precisely 66 years to the day after the first sitting. The 73 attended a group testing session at a large public hall in Aberdeen town center on June 1, 1998, the 66th anniversary of the original testing session. The hall was specially furnished with desks and chairs for a group examination. Some 28 other subjects attended on dates up to 5 months later at times convenient to them. All but one—who attended in a wheelchair—of the 101 re-tested subjects were ambulant. None of the 101 was suffering from any major physical or mental illness or medication known to affect cognitive functioning.

Mental Test and Procedure

The Moray House Test was administered in a group fashion using the same instructions as those used in 1932 (Scottish Council for Research in Education, 1933). Forty-five minutes were allowed for the completion of the test. Only two of the tests’ items required minor altering from the 1932 version. A question involving shillings and pence was altered to feet and inches because, whereas money altered to a decimal format in the UK in 1971, the measurement of distance is still principally duodecimal, especially among old people. Another question archaically referring to “vitamine” was changed to read “vitamins.” In addition to the newly gathered 1998 test scores, all subjects’ Moray House Test scores were identified from the records of the 1932 sitting.

On a separate occasion, 97 of the 101 subjects completed a further mental ability test to provide concurrent validity for the 1998 scores on the Moray House Test. The test was Raven’s Progressive Matrices (Raven, Court, & Raven, 1977), a non-verbal pattern-completion test. Raven’s Matrices test is a good indicator of general intelligence (Spearman’s g; Carroll, 1993). The Raven test was administered to subjects individually by trained researchers using a time limit of 20 min.

Results

The mean score on the Moray House Test for the 101 subjects in 1932 was 43.3 (SD = 11.9), and for the same subjects in 1998 was 54.2 (11.8) (Table 2). Mean scores for men and women were very similar at age 11 but, at age 77, men scored higher than women by almost three points. A mixed model analysis of variance of Moray House Test scores was carried out with time as a repeated measure (1932 score vs. 1998 score) and sex as a between subjects factor. The effect of time was highly significant, with people scoring better at age 77 years than at age 11 (F = 118.0, df = 1.99, p < 0.001). There was no significant overall effect of sex on test scores (F = 0.3, df = 1.99, p = 0.6). There was a statistical trend in the interaction between time and sex, with men tending to gain higher scores over the 66-year gap between tests (F = 2.6, df = 1.99, p = 0.1).

Table 2 Descriptive Statistics of, a...

Table of contents

• Cover
• Half Title
• Title
• Copyright
• Contents
• Acknowledgements
• Series Preface
• Introduction
• PART I COGNITION AND AGING
• PART II SOCIAL AND EMOTIONAL FUNCTIONING IN OLD AGE
• PART III LIFESTYLE AND WELL-BEING IN OLD AGE
• PART IV PSYCHOLOGICAL ASPECTS OF DEMENTIA
• PART V FAMILIES AND CARERS IN OLD AGE
• PART VI PSYCHOLOGICAL ASPECTS OF MENTAL HEALTH PROBLEMS IN OLD AGE
• Name Index