Full text of DOI:10.1093/geronb/57.2.P144

Journal of Gerontology: PSYCHOLOGICAL SCIENCES
Copyright 2002 by The Gerontological Society of America
2002, Vol. 57B, No. 2, P144–P152
Age Changes and Differences in Personality Traits and
States of the Old and Very Old
Peter Martin,1 M. Valora Long,1 and Leonard W. Poon2
1German Centre for Research on Aging, University of Heidelberg, Germany and Gerontology Program,
Iowa State University, Ames.
2Gerontology Center, University of Georgia, Athens.
The purpose of this study was to examine stability and change in personality traits and states for 3 age groups:
centenarians, octogenarians, and sexagenarians. One hundred seventy-nine older adults participated in the
2-wave study. Results concerning age-group differences indicated that centenarians scored higher in Suspicious-
ness but lower in Intelligence and Stress when compared with the other 2 age groups. Octogenarians were lower
in the personality traits Intelligence, Dominance, and Conscientiousness when compared with sexagenarians. Oc-
togenarians were lower in the personality state Arousal, but higher on Regression. Results from the longitudinal
analyses for centenarians indicated lower scores for Sensitivity, but higher scores for Radicalism (both personal-
ity traits), as well as higher scores of Fatigue and Depression (personality states) at follow-up. For the younger 2
age groups, age changes included higher scores for Sensitivity and Suspiciousness (personality traits). Stability
scores for traits and states were considerably lower for centenarians when compared with the younger age
groups.
ERSONALITY traits have been assessed in many stud-
ies including older adults (Heatherton & Weinberger,
explain between-group differences in personality (Douglas
& Arenberg, 1978; Schaie & Parham, 1976; Woodruff &
Birren, 1972). Recent results champion stability of person-
ality traits in adulthood (Costa & McCrae, 1994; McCrae,
1993), but, likewise, several other studies indicate that
change in personality is possible (Helson & Stewart, 1994).
In general, two different approaches are taken to study
personality stability (Costa & McCrae, 1994): stability of
mean levels to estimate normative changes in personality
variables with age and stability of individual differences re-
ferring to the stability of individual’s rank ordering. Al-
though results seem to suggest that mean level changes are
small or nonexistent, studies emphasizing the stability of in-
dividual differences demonstrate some traits with very high
stability, such as Neuroticism and Openness, with other fac-
tors showing lower levels of stability, particularly over
longer periods of time (Costa & McCrae, 1994). Interin-
dividual stability of specific traits across extended time
periods is quite substantial, but the longer the time inter-
val between assessments, the greater the instability (Kogan,
1990).
Recent findings from the Berlin Aging Study indicated a
negative age trend for Extraversion and Openness, whereas
there was no significant age difference for Neuroticism
(Smith & Baltes, 1999). What is not known is whether per-
sonality remains stable at the extreme end of the life span or
whether personality becomes more fluid in very late life
(Costa, McCrae, & Arenberg, 1980).
Today there is growing documentation that personality
attributes have both state and trait characteristics (Bengtson,
1996; Headey & Wearing, 1991). Much of the stability in
personality has been investigated by trait concepts that rely
on items indicating stability. Much less attention has been
paid to potentially more variable personality states (Adkins
et al., 1996; Nesselroade, 1988). Personality states tap into
P
1994; Helson & Wink, 1992; McCrae & Costa, 1990). Very
little work, however, has been done within and between
older age groups that include the old old (i.e., 80 years and
older) and the oldest old (i.e., 85 years and older; cf. Baltes
& Mayer, 1999, for an exception). The purpose of this study
was to examine age changes and age differences on person-
ality traits and states for three age groups: centenarians, oc-
togenarians, and sexagenarians.
The demographic age group defined as the “oldest old” is
the fastest growing segment of our population (Taeuber &
Rosenwaike, 1992; Wade, 1992). More specifically, cente-
narians have also experienced a steady growth in numbers,
with more than 37,000 centenarians counted in the 1990
Census and a projection of almost 850,000 centenarians by
the year 2050 (U.S. Department of Health and Human Ser-
vices, 1999). Only a few studies have described in detail the
characteristics of this population. Perhaps the most detailed
studies are concerned with the functional, physical, and
cognitive condition of this population (Holtsberg, Poon,
Noble, & Martin, 1995; Johansson, Zarit, & Berg, 1992;
Martin, Poon, Kim, & Johnson, 1996; Seeman et al., 1994).
Although there can be substantial physical and cognitive
impairment in many of these very old individuals, the
strength of these persons is perhaps not expressed in their
level of cognitive or physical functioning, but rather in their
resilient self (Baltes & Baltes, 1990) or robust personality.
We have therefore emphasized in our earlier studies that
personality is an important aspect to study in the oldest old
(Adkins, Martin, & Poon, 1996; Martin et al., 1992).
Previous research still remains inconclusive on whether
personality can change (Butcher et al., 1991; Field & Mill-
sap, 1991; Helson & Wink, 1992; Kogan, 1990; McCrae &
Costa, 1990) and to what extent cohort differences might
P144

CHANGES AND DIFFERENCES IN PERSONALITY
P145
nonsystematic situational variation, allowing for more in-
traindividual variability over time. Using state concepts par-
allel to trait dimensions also widens the scope of personality
research, because several personality dimensions are as-
sessed (i.e., stress, fatigue, and guilt) that are not typically
components of enduring personality characteristics. There-
fore, the purpose of the present study was to assess age dif-
ferences and changes in personality traits and personality
states within a population of old and very old adults. If there
is an important distinction between relatively stable person-
ality traits and more variable personality states, then we
would expect more stability in trait and more nonsystematic
variability in personality state measures.
In a preliminary study, when comparing three age groups
in later life, we reported on cross-sectional findings of per-
sonality, coping, and mental health (Martin et al., 1992). We
noted age differences in basic personality traits, such as
higher Suspiciousness and lower Tension scores in cente-
narians. Other studies noted that very old individuals are
less energetic (Field & Millsap, 1991), show more depres-
sive symptoms (Martin, Rott, Kerns, Poon, & Johnson,
2000), and may score higher on Introversion and lower on
Openness (Butcher et al., 1991; Smith & Baltes, 1999) than
younger age groups. Age differences, however, cannot in-
form us about possible longitudinal changes of personality.
A follow-up study allowed us to assess the survivors’ per-
sonality stability and change over time. Furthermore, by
following very old persons over time, we were also able to
assess the possible impact of cognitive impairment on per-
sonality changes.
Building on the existing research, this project had several
research questions in mind. First, considering adaptational
characteristics of the oldest old, we focused on mean level
of age differences and changes for the three age groups un-
der study. Consistent with the literature, we hypothesized no
differences or changes for measures of Neuroticism (i.e.,
Emotional Stability, Insecurity, Tension, and state Anxiety),
but lower levels concerning Extraversion (i.e., Warmth, Dom-
inance, Boldness, and state Extraversion) and higher levels
of Fatigue, Depression, and Suspiciousness, particularly in
the very old age groups. With regard to stability of individ-
ual differences, we hypothesized lower levels of stability for
centenarians because of their increased frailty over time.
pression were significant predictors of Time 2 participation
(B ꢀ ꢁ.03, p ꢂ .05, and B ꢀ ꢁ.07, p ꢂ .05, respectively.
Of the personality variables, Intelligence, Apprehension,
and Control (personality traits), as well as Stress and Fa-
tigue (personality states) significantly predicted participa-
tion (B ꢀ .14, p ꢂ .05, B ꢀ .17, p ꢂ .05, B ꢀ .22, p ꢂ .05,
B ꢀ .17, p ꢂ .05, and B ꢀ ꢁ.39, p ꢂ .01, respectively).
Taken together, Time 2 participants were more likely to be
younger, less depressed, more intelligent, more apprehen-
sive and controlled, and more stressed, but less fatigued.
Demographic characteristics of the sample are summa-
rized in Table 1. Sixty-seven participants were in their six-
ties (M ꢀ 64.9), 57 were in their eighties (M ꢀ 82.8), and
55 were centenarians (M ꢀ 100.5) at the first time of testing.
Two thirds of the sample were female, whereas one third
were male. Approximately 30% of the sample were African
American. More than 70% of the sample rated their health
as either good or excellent.
The timing of retesting was different for centenarians and
the two younger age groups. We decided to retest the octoge-
narians and sexagenarians after 5 years to allow for change
to occur. Five years obviously would have been too long a
time for retesting centenarians. Therefore, centenarians were
retested after 18 months. The consequence of the different
testing times is that data analysis had to be conducted sepa-
rately for centenarians and the other two age groups.
The baseline centenarian sample was recruited through
the University of Georgia’s Survey Research Center, the
Office of the Governor of Georgia, the media, and state and
local agencies on aging. Centenarians and their families
were asked to contact the Gerontology Center at the Univer-
sity of Georgia. After obtaining information about the cen-
tenarians, we sent out a letter with information to prospec-
tive participants with an invitation to participate in the
study. Follow-up phone calls were made to answer any
question and to schedule preliminary appointments to ex-
Table 1. Demographic Characteristics
Age group
Total
Variable
Age
n
Percenta
60–69
80–89
ꢃ100
Sexagenarians
67
57
55
37.9
31.6
30.5
Octogenarians
Centenarians
Total
METHODS
179
100.0
Participants
Gender
The original baseline study included 327 older adults during
the first wave of the study, whereas 205 participants were
retested during the second wave. Twenty-six participants
had missing data on the personality questionnaire, leaving a
sample size of 179 participants for this study.
To assess whether those who participated in the first
wave of the study were different from those who partici-
pated in the second wave, we computed three logistic re-
gressions: the first one with age group, gender, race, subjec-
tive health, instrumental activities of daily living, mental
status, education, and depression as predictors, the second
with personality traits, and the third with personality states
as predictors of participation at Time 2. Age group and de-
Male
Female
Total
54
125
179
30.2
69.8
100.0
25
42
67
19
38
57
10
45
55
Ethnicity
Caucasians
African Americans
Total
124
55
179
69.3
30.7
100.0
43
24
67
45
12
57
36
19
55
Subjective health ratings
Poor
Fair
Good
Excellent
Total
5
39
93
41
178
2.8
21.9
52.2
23.0
99.9
3
8
36
19
66
0
12
33
12
57
2
19
24
10
55
aPercentages may not add up because of rounding.

P146
MARTIN ET AL.
plore the question of participation. During the first visit, in-
formed consent was obtained and the Mini-Mental Status
Exam (MMSE; Folstein, Folstein, & McHugh, 1975) was
used as a screening device to determine eligibility of partic-
ipants for the baseline recruitment. A cutoff score of 23 or a
score of 2 on the Global Deterioration Scale (Reisberg, Fer-
ris, de Leon, & Crook, 1982) had to be reached to partici-
pate in the study. During the follow-up testing, all surviving
participants were assessed. At that time, no sexagenarians
and only one octogenarian obtained a score less than 23 on
the MMSE. However, only 60% of the surviving centenari-
ans (compared with 69% at Time 1) reached this cutoff
score at the second measurement time. Participants were all
community dwelling.
Sexagenarians and octogenarians were recruited with
random-digit dialing by the University of Georgia Survey
Research Center to obtain a sample that would imitate the
gender and racial characteristics of citizens of Georgia.
Testing with these two age groups was primarily done in
small groups at central community settings. Typically 5 to
15 participants were invited for a testing session. Most par-
ticipants of the younger age groups filled out questionnaires
on their own, but, in cases of visual impairment, interview-
ers posed questions directly to the participants.
abilities with intervals of 4 to 7 days ranging from .58 to
.92, depending on the trait. At 2-month intervals, reliabili-
ties ranged from .35 to .85.
Personality states were assessed by the 8SQ (Institute for
Personality and Ability Testing, 1974). This instrument was
designed to complement the traditional trait concepts mea-
sured by the 16PF. The 8SQ included Anxiety (“I’m so
worked up and worried that my hands are shaking”), Stress
(“At the moment I’m not feeling any great stress or strain”),
Depression (“In my present mood I think I’d almost be in
tears if things went wrong”), Regression (“I’m pretty de-
manding and complaining today”), Fatigue (“I am very tired
today”), Guilt (“At the moment I’m feeling sort of guilty
about things”), Extraversion (“If a social gathering were go-
ing on right now, I’d probably just sit back and watch the
others”), and Arousal (“The way I feel now I could get en-
thusiastic about almost anything”). Test–retest reliability
coefficients reported by the Institute for Personality and
Ability Testing (1974) varied from .88 to .96. All 16 trait
and eight state measures were used in the analyses.
RESULTS
To assess change, we computed univariate repeated mea-
sures analyses of variance (ANOVAs) for centenarians,
whereas 2 (age group) ꢄ 2 (time of measurement) repeated
(ANOVAs) were computed for the other two age groups.
Additional 3 (age group) ꢄ 2 (time of measurement) (ANO-
VAs) were computed to test for age-group differences be-
tween centenarians and the other two age groups. Stability
over time was calculated with Pearson correlations, and sta-
bility differences across age groups were assessed with
Fisher’s Z test.
Measures
Measurement instruments relevant for this study included
the fourth edition of the Sixteen Personality Factor Ques-
tionnaire (16PF) questionnaire (Form A), assessing person-
ality traits and the Eight State Questionnaire (8SQ) question-
naire, assessing personality states. The 16PF measured the
following primary personality traits: Warmth (“If asked to
work with a charity drive, I would accept or politely say I’m
too busy”), Intelligence (“Spade” is to “dig” as “knife” is to
“sharp,” “cut,” or “point”), Emotionality (“I feel a bit ner-
vous of wild animals even when they are in strong cages”),
Dominance (“I like it when I know so well what the group
has to do that I naturally become the one in command”), Im-
pulsivity (“I enjoy doing ‘daring,’ foolhardy things ‘just
for fun’”), Conformity (“I find the sight of an untidy room
very annoying”), Boldness (“I find it easy to mingle among
people at a social gathering”), Sensitivity (“Because it is not
always possible to get things done by gradual, reasonable
methods, it is sometimes necessary to use force”), Suspi-
ciousness (“I have sometimes been troubled by people’s
saying bad things about me behind my back, with no
grounds at all”), Imagination (“You can almost always no-
tice on people’s faces when they are dishonest”), Shrewd-
ness (“I would rather take the gamble of a job with possibly
large but uneven earnings than one with a steady, small sal-
ary”), Insecurity (“Once in a while I have a sense of a vague
danger or sudden dread for reasons that I do not under-
stand”), Radicalism (“I think society should let reason lead
it to new customs and throw aside old habits or mere tradi-
tions”), Self-Sufficiency (“I like to do my planning alone,
without interruptions and suggestions from others”), Self-
Discipline (“I like to go my own way instead of acting on
approved rules”), and Tension (“I sometimes get in a state
of tension and turmoil as I think of the day’s happenings”).
Cattell, Eber, and Tatsuoka (1970) reported test–retest reli-
The first data analysis step was concerned with age-group
effects, comparing personality for the octogenarians and
sexagenarians (see Table 2). The omnibus multivariate anal-
ysis of variance (MANOVA) test for age-group differences
was significant for personality traits and personality states,
Wilks’s ꢅ (16,228) ꢀ .807, p ꢂ .001, and Wilks’s ꢅ (8,208) ꢀ
.89, p ꢂ .01, respectively. Differences were obtained for In-
telligence, Dominance, and Conscientiousness with regard
to the personality trait questionnaire, indicating that octoge-
narians were lower on all three traits. For the personality
states questionnaire, age-group differences were obtained
for Regression and Arousal, indicating that octogenarians
were higher in Regression, but lower in Arousal.
The overall MANOVA test did not reveal any overall
changes over time regarding personality traits, Wilks’s ꢅ
(16,228) ꢀ .95, p ꢆ .05. A statistical trend was observed for
changes over time in personality states, Wilks’s ꢅ (16,228) ꢀ
.93, p ꢂ .06. For the younger two age groups, significant in-
creases were obtained for the personality traits Sensitivity
and Suspiciousness (see Table 2). For personality states, a
significant interaction was obtained for Depression, indicat-
ing that sexagenarians had decreasing scores over time,
whereas octogenarians had increasing scores.
Change over time was observed separately for centenari-
ans (see Table 3), because of the differential retest interval.
The omnibus MANOVA test did not indicate any overall
personality changes over time for personality traits or states,
Wilks’s ꢅ (16,87) ꢀ .88, p ꢆ .05, and Wilks’s ꢅ (8,98) ꢀ

CHANGES AND DIFFERENCES IN PERSONALITY
P147
Table 2. Mean Changes in Personality Traits and States of Octogenarians and Sexagenarians
60–69
80–89
Age group
Time
AꢄT
Dependent variables
T1
T2
T1
T2
M
ꢇ2
M
ꢇ2
M
ꢇ2
Personality Traits (df ꢀ 123)
Warmth
5.63
(1.45)
5.21
(2.24)
5.46
(2.27)
4.58
(2.05)
4.28
(1.77)
6.60
(1.99)
5.52
(1.67)
6.00
(2.01)
5.46
5.40
(1.83)
5.03
(1.72)
5.39
(1.95)
4.63
(1.91)
4.43
(1.65)
6.70
(1.67)
5.51
(1.68)
6.30
(1.88)
5.57
5.71
(1.98)
4.29
(1.88)
5.04
(1.67)
3.82
(1.48)
4.30
(1.61)
6.02
(1.60)
5.32
(1.60)
5.71
(1.89)
5.32
6.05
(1.79)
4.02
(1.93)
5.16
(1.86)
4.00
(1.64)
4.21
(1.63)
6.07
(1.67)
5.16
(1.60)
6.11
(1.73)
5.80
1.81
10.80***
.93
.25
1.53
.00
3.01
.07
Intelligence
Emotional Stability
Dominance
.08
.04
.04
.31
4.88*
.10
.50
.15
Enthusiasm
.01
1.04
.05
Conscientiousness
Boldness
4.79*
1.11
.78
.20
.30
.18
Sensitivity
4.91*
3.96*
1.74
1.67
.03
.04
.03
.03
Suspiciousness
Imagination
Shrewdness
Insecurity
.13
1.72
.44
(1.76)
4.43
(2.05)
6.27
(1.97)
5.18
(1.88)
4.33
(1.81)
6.57
(1.87)
5.19
(2.08)
4.20
(1.93)
6.75
(1.78)
5.14
(1.74)
3.86
(1.46)
7.00
(1.89)
5.11
1.58
2.99
.03
.05
.08
(1.93)
4.72
(1.80)
6.61
(2.04)
7.04
(1.54)
5.31
(1.83)
4.90
(1.98)
6.64
(1.67)
6.72
(1.98)
5.28
(1.76)
4.66
(1.56)
6.30
(1.93)
6.68
(1.67)
5.21
(1.68)
4.93
(1.70)
6.77
(1.83)
6.61
(1.78)
5.23
Radicalism
.02
1.65
1.92
1.05
.00
.08
Self-Sufficiency
Self-Discipline
Tension
.13
1.50
.68
.79
.06
.03
(2.13)
(1.98)
(1.71)
(1.83)
Personality States (df ꢀ 95)
Anxiety
4.70
(1.61)
4.34
4.74
(1.66)
3.88
4.89
(1.30)
3.74
5.09
(1.59)
3.80
1.12
.38
.87
.15
.35
Stress
1.46
(1.97)
5.30
(1.52)
4.98
(1.49)
5.06
(1.66)
4.42
(1.86)
5.00
(1.56)
5.50
(1.78)
5.02
(1.53)
4.80
(1.40)
5.04
(1.70)
4.50
(1.81)
5.42
(1.42)
5.46
(1.71)
5.33
(1.23)
5.39
(1.18)
5.37
(1.78)
4.59
(1.61)
4.74
(1.69)
4.85
(1.96)
5.76
(1.51)
5.76
(1.48)
5.89
(1.59)
5.28
(1.99)
4.83
(1.68)
4.93
Depression
Regression
Fatigue
2.39
.24
5.68*
2.97
3.36
1.71
1.10
.27
.06
8.22**
3.88
.08
.28
2.87
2.94
3.09
.07
Guilt
1.86
Extraversion
Arousal
2.33
6.37*
.06
(1.59)
(1.18)
(1.66)
(1.34)
Notes: Standard deviations appear in parentheses. T1 ꢀ Time 1; T2 ꢀ Time 2.
*p ꢂ .05; **p ꢂ .01; ***p ꢂ .001.
.90, p ꢆ .05, respectively. For centenarians, a significant
decrease was obtained for the personality trait Sensitivity,
but an increase in Radicalism. The personality states Fatigue
and Depression yielded a significant increase over time.
Age Group ꢄ Time repeated ANOVAs were computed
again with the inclusion of all three age groups. Main age
group effects were obtained for Intelligence, F(2,170) ꢀ
26.45, p ꢂ .001, ꢇ2 ꢀ .24, Dominance, F(2,171) ꢀ 3.53,
p ꢂ .05, ꢇ2 ꢀ .04, Sensitivity, F(2,171) ꢀ 5.26, p ꢂ .01,
ꢇ2 ꢀ .06, Suspiciousness, F(2,170) ꢀ 4.85, p ꢂ .01, ꢇ2 ꢀ .05,
and Tension, F(2,171) ꢀ 4.11, p ꢂ .05, ꢇ2 ꢀ .05. Signifi-
cant age group differences were also obtained for personal-
ity states: Stress, F(2,146) ꢀ 7.43, p ꢂ .01, ꢇ2 ꢀ .09, Re-
gression, F(2,146) ꢀ 6.47, p ꢂ .01, ꢇ2 ꢀ .08, Fatigue,
F(2,146) ꢀ 7.07, p ꢂ .01, ꢇ2 ꢀ .09, and Arousal, F(2,145) ꢀ
3.22, p ꢂ .05, ꢇ2 ꢀ .04. Post hoc Scheffé tests indicated that

P148
MARTIN ET AL.
F(1,171) ꢀ 5.82, p ꢂ .05, ꢇ2 ꢀ .03, and Fatigue, F(1,146) ꢀ
10.52, p ꢂ .01, ꢇ2 ꢀ .07, when compared with the other
age groups. Three significant Age Group ꢄ Time interactions
were obtained: Sensitivity as a personality trait, F(1,171) ꢀ
4.88, p ꢂ .01, ꢇ2 ꢀ .05, and Depression, F(1,146) ꢀ 3.67,
p ꢂ .05, ꢇ2 ꢀ .05, as well as Fatigue, F(1,146) ꢀ 3.15, p ꢂ
.05, ꢇ2 ꢀ .04, as personality states. For Sensitivity, sexage-
narian and octogenarian scores increased, whereas, for cen-
tenarians, Sensitivity scores decreased. Post hoc Scheffé
tests indicated that centenarians differed from the other two
age groups at the follow-up testing only. For Depression,
sexagenarian scores decreased, whereas, for octogenarians
and centenarians, scores increased over time. Post hoc
Scheffé tests determined that octogenarians and centenari-
ans differed from sexagenarians at Time 2 only. Finally, Fa-
tigue scores increased for octogenarians and centenarians,
but stayed stable for sexagenarians. Post hoc Scheffé tests
determined that octogenarians and centenarians differed
from sexagenarians at Time 2 only.
Stability measures over time were computed separately
for each age group for the personality measures (see Table
4). For personality traits, sexagenarians had the lowest sta-
bility for Self-Discipline and the highest for Tension. For
octogenarians, the lowest stability coefficient was found for
Shrewdness and the highest for Suspiciousness. For cente-
narians, the lowest stability was found for Intelligence and
the highest for Boldness.
Stability measures for personality states indicated that
sexagenarians had lowest scores for Stress and highest for
Fatigue. Octogenarians had lowest stability scores in Re-
gression, and—as did the sexagenarians—highest scores in
Fatigue. Finally, centenarians had lowest state stability in
Depression, whereas their highest stability measures were
noted in Guilt. Stabilities were compared across age groups
by computing Fisher’s Z test. This test is appropriate for
testing significant differences of two correlation coeffi-
cients representing two different populations (Hays, 1988).
The results indicated that stabilities contrasting octogenari-
ans and centenarians with sexagenarians differed for Intelli-
gence (Z ꢀ 2.31, p ꢂ .05, and Z ꢀ 3.57, p ꢂ .05, respec-
tively), for Sensitivity (Z ꢀ 2.25, p ꢂ .05, and Z ꢀ 3.04,
p ꢂ .05, respectively), and for Imagination (Z ꢀ 2.71, p ꢂ
.05, and Z ꢀ 4.02, p ꢂ .05, respectively; see Table 4). Sta-
bilities contrasting centenarians with octogenarians and sex-
agenarians differed for Dominance (Z ꢀ 2.67, p ꢂ .05, and
Z ꢀ 4.08, p ꢂ .05, respectively), for Fatigue (Z ꢀ 2.32,
p ꢂ .05, and Z ꢀ 2.32, p ꢂ .05, respectively) and for Extra-
version, (Z ꢀ 1.96, p ꢂ .05, and Z ꢀ 2.35, p ꢂ .05, respec-
tively).
Table 3. Mean Changes (Within Centenarians) in Personality
Traits and States
Dependent Variables
Time 1
Time 2
F
ꢇ2
Personality Traits (df ꢀ 51)
Warmth
5.71
(1.74)
2.90
(1.58)
5.51
5.75
(1.73)
3.06
(2.08)
5.27
.02
.20
Intelligence
Emotional Stability
Dominance
.71
(1.77)
4.45
(1.70)
4.55
.09
(1.63)
4.43
(1.83)
4.18
Enthusiasm
.98
(1.90)
6.20
(1.47)
5.22
(1.85)
6.20
(1.67)
5.14
Conscientiousness
Boldness
.01
.18
(1.68)
5.47
(1.51)
6.40
(1.82)
3.78
(1.25)
6.88
(1.55)
4.96
(1.47)
6.34
(1.89)
3.88
(1.81)
7.14
Sensitivity
4.58*
.03
.08
Suspiciousness
Imagination
Shrewdness
Insecurity
.11
.73
(1.84)
5.10
(1.64)
4.88
.52
(1.94)
4.98
(1.88)
6.80
(1.65)
7.04
(1.51)
4.31
(1.70)
5.69
(1.96)
6.84
(1.59)
6.67
(1.57)
4.59
Radicalism
4.80*
.02
.09
Self-Sufficiency
Self-Discipline
Tension
1.95
.86
(1.85)
(1.80)
Personality States (df ꢀ 53)
Anxiety
4.92
(1.45)
3.32
(1.96)
5.38
(1.38)
5.55
(1.32)
5.72
5.11
(1.55)
2.68
(1.86)
5.91
(1.50)
5.72
(1.42)
6.42
.54
4.02
4.07*
.55
Stress
Depression
Regression
Fatigue
.07
.16
9.79**
.04
(1.43)
4.66
(1.20)
4.72
Guilt
(1.81)
5.09
(1.60)
5.17
(1.79)
4.75
(1.71)
4.90
Extraversion
Arousal
1.30
.31
(1.57)
(1.39)
Note: Standard deviations appear in parentheses.
*p ꢂ .05; **p ꢂ .01.
Because cognitive impairment can be quite prevalent in
very old individuals, possibly affecting results for the cente-
narian survivors, we divided the centenarian group into a
higher cognitively functioning group (with MMSE scores ꢃ
23, n ꢀ 29) and a lower cognitively functioning group (with
MMSE scores ꢂ 23, n ꢀ 20). (We thank one of the anony-
mous reviewers for this suggestion.) Mean trait stabili-
ties were indeed higher for centenarians in the higher cogni-
tive functioning group, however, stabilities were lower for
mean stabilities for personality states. Significant state sta-
bilities were only obtained for Guilt, r(29) ꢀ .55, and
all three groups were significantly different from each other
in Intelligence, with centenarians having the lowest scores
and sexagenarians having the highest scores. Post hoc tests
also revealed that centenarians had significantly higher
scores for Suspiciousness, but lower scores for Stress when
compared with both younger age groups.
Age changes for all three age groups revealed that cen-
tenarians had significantly lower scores in Radicalism,

CHANGES AND DIFFERENCES IN PERSONALITY
P149
Table 4. Stability Measures for Personality Traits and States
Table 5. Stability Measures for Personality Traits and States by
Mental Status (Centenarians Only)
60–69
80–89
ꢃ100
Personality measure
(n ꢀ 67)
(n ꢀ 57)
(n ꢀ 53)
MMSE ꢂ 23
(n ꢀ 20)
MMSE ꢃ 23
(n ꢀ 29)
Personality measure
Personality traits
Warmth
.45**
.60**a
.73**a
.67**a
.68**
.53**
.72**
.74**a
.56**
.69**a
.53**a
.58**
.47**
.45**
.42**
.77**a
.60
.47**
.25b
.28*
.02b
.30*b
.04b
.52**
.26
.67**
.36**b
.31*
.09b
.26a,b
.34*
.32*
.41**
.21
Personality Traits
Warmth
Intelligence
Emotional Stability
Dominance
Enthusiasm
Conscientiousness
Boldness
.06
ꢁ.36
.39
ꢁ.18
.60**
.10
.60**
.32
.20
ꢁ.09
ꢁ.13
.36
.77**a
.21
.08
.62**a
.22
.28
.44*
.40*
ꢁ.03
.43*
.32
.62**
.37
.24
.57**a,b
.51**a
.52**
.49**
.52**
.49**b
.62**
.33**b
.07b
.57**
.26
.29*
.31*
.61**a,b
.43
Intelligence
Emotional Stability
Dominance
Enthusiasm
Conscientiousness
Boldness
Sensitivity
Suspiciousness
Imagination
Shrewdness
Insecurity
Radicalism
Self-Sufficiency
Self-Discipline
Tension
Sensitivity
Suspiciousness
Imagination
Shrewdness
Insecurity
Radicalism
Self-Sufficiency
Self-Discipline
Tension
.24
.41*
.50**
.05b
.36
.30
ꢁ.01b
.31
.33**b
.30
Overall mean
Personality states
Anxiety
Overall mean
Personality States
Anxiety
.53**
.26
.27
.34*
.44**a,b
.26b
.65**a
.49**
.55**a
.42**
.43
.24
.29
Stress
.35
.13
.19
.27
.32
.55*
.31
.44*
.32
.18
.35
.08
.35
.09
.14
.02
.02
.15
Depression
Regression
Fatigue
Guilt
Extraversion
Arousal
.54**a
.57**a
.64**a
.42**
.59**a
.43**
.50
.12b
.30*a,b
.31*b
.32*
.23b
.26
Stress
Depression
Regression
Fatigue
Guilt
Extraversion
Arousal
Overall mean
.26
Overall mean
Note: Stabilities with different subscripts are significantly different from
each other.
*p ꢂ .05; **p ꢂ .01; ***p ꢂ .001.
Notes: Stabilities with different subscripts are significantly different from
each other. MMSE ꢀ Mini-Mental State Exam.
*p ꢂ .05; **p ꢂ .01; ***p ꢂ .001.
Arousal, r(29) ꢀ .44, in the lower cognitively functioning
group. Fisher’s Z tests were computed for all personality
traits and states, but only two trait dimensions yielded sig-
nificant stability differences (see Table 5). The lower cogni-
tively functioning group showed significantly higher stabili-
ties in the personality traits Radicalism and Tension (Z ꢀ
3.03, p ꢂ .05, and Z ꢀ 2.24, p ꢂ .05, respectively).
Dominance). Rather, differences between octogenarians
and sexagenarians were obtained for Intelligence, Domi-
nance, Conscientiousness, Regression, and Arousal. The
older participants were lower in Intelligence, less dominant
and conscientious, and lower in Arousal, but higher in Re-
gression. Cross-sectional differences, of course, can be due
to age changes or age-group differences. Some of the re-
sults, such as lower scores on Intelligence, mirror other age-
group comparison findings (e.g., Schaie, 1996). Why the
older age group is less dominant and conscientious is less
clear, but perhaps the Depression era and the experience of
World War II influenced their pattern of personality, as the
older age group were young adults at that time. Possible age
changes may reflect cognitive decline, but none of the
cross-sectional results were mirrored in the longitudinal
analysis, suggesting that the mean level of personality re-
mains stable into very old age (Costa & McCrae, 1994).
Overall, few personality changes were obtained over
time. Even though there were no significant changes in
overall personality patterns, it is still important to assess
changes in particular source traits (Cattell, 1993). Changes
were observed for Suspiciousness (as hypothesized) and
Sensitivity in the younger old age groups, and for Sensitiv-
ity and Openness in centenarians. The increase of Suspi-
ciousness, particularly in the octogenarian age group, is
noteworthy, because it corresponds to the finding that cente-
DISCUSSION
In our earlier work, we emphasized the importance of indi-
vidual characteristics as contributors to optimal adjustment
to late life changes (Poon et al., 1997). We consider person-
ality traits and states to be important when one is faced with
adverse health and social changes that very old people par-
ticularly encounter (Zarit, 1996). To serve as an important
resource, personality would have to be a stable characteris-
tic. In the current study, we assessed personality traits and
states at two time periods with a sample of second-wave
survivors of three older age groups. We explored what out-
standing characteristics might exist in the oldest groups and
how stable those characteristics would be over time.
The overall results seem to suggest conflicting results
concerning age-group differences. As hypothesized, differ-
ences were not obtained for measures of Neuroticism (i.e.,
Emotional Stability, Insecurity and Tension, and state Anxi-
ety). Contrary to our hypothesis, age group differences were
also not obtained for measures of Extraversion (except for

P150
MARTIN ET AL.
narians have higher scores in Suspiciousness than younger
old-age groups (Martin et al., 1992). If this finding can be
replicated and continues to emerge as an important change
variable among the oldest old, it may well mark an impor-
tant survival characteristic for the oldest old. The impor-
tance of suspiciousness can be explained by increased para-
noia and fear of victimization in the older adults (Blazer,
George, & Hughes, 1988; Ferraro & LaGrange, 1992).
The change in Sensitivity is striking, because it indicates
a different direction in the group comparison. Although
Sensitivity scores increased in the younger old-age groups,
they tended to decrease at the second testing time in cente-
narians. High scores on this trait suggest that persons are
tender-minded, dependent, fidgety, and insecure (Krug,
1981). People who score high on this trait demand attention
and help, and they may also be impatient and temperamen-
tal (Institute for Personality and Ability Testing, 1991).
These characteristics seem to become more prevalent for
adults in their 60s and 80s, perhaps indicating an increased
sense of vulnerability. To survive beyond 100, however, it
may be increasingly important to feel tough minded, less
dependent, and more secure. The change in Sensitivity for
centenarians may also correspond with a higher score in
Radicalism; over time and toward the end of life, it may be-
come more acceptable to stay open for experiences. For
state measures, Fatigue and Depression scores increased in
centenarians. These results are consistent with our hypothe-
ses and confirm earlier findings by Field and Millsap
(1991), who reported that very old people are less energetic
than younger age groups. It is possible that toward the bio-
logical end of life, physical reserve capacities start to dimin-
ish and older individuals may have to household with their
individual reservoir of strength. Noticing such changes,
centenarians may also show increased levels of depressive
symptoms (Martin et al., 2000). In general, then, changes in
several source traits and states may be a result of increased
demands to adapt to changes in very late life or may be an
indication for the depletion of resilience in very old age.
Although some of these personality changes were ob-
served, it should be noted that many personality traits did
not change over time. These results are consistent with find-
ings by McCrae and Costa (1990). However, it may be nec-
essary to not only assess the broad Big Five aspects of per-
sonality, but also look at primary-level traits that, perhaps,
may be more likely to change over time (Cattell, 1993).
The inspection of age-group differences and age changes
when including all three age groups revealed mostly similar
results, but also a few differences. The same age-group ef-
fects were obtained for Intelligence, Dominance, Regres-
sion, and Arousal. New age differences were obtained
indicating differences for centenarians in Sensitivity, Suspi-
ciousness, Tension, Stress, and Fatigue. With regard to age
changes, increases for Suspiciousness were only obtained
for the younger two age groups, whereas Radicalism and
Fatigue increased significantly when centenarians were in-
cluded. Significant interactions were obtained for Sensitiv-
ity (which decreased in centenarians, but increased in the
younger two age groups), Fatigue, and Depression (which
increased in the older two age groups). Although these
results have to be viewed with caution, as the retesting
time for centenarians was shorter, the direct comparison
of all three age groups possibly suggests unique personal
strengths and weaknesses, particularly for centenarians.
Lower scores in Sensitivity, Tension, and Stress in combi-
nation with higher scores in Suspiciousness and Radicalism
point to continued personal adaptive capacity, a robust or
resilient self (Baltes & Baltes, 1990). Higher scores in Fa-
tigue and Depression, on the other hand, point to lower re-
serve capacity in very late life.
The second question of this study was concerned with the
interindividual stability of personality traits and states. To
this end, we examined stability coefficients for personality
traits and states. Consistent with our hypothesis, the stabil-
ity coefficients for centenarians were significantly lower
than those for the other two age groups, even though cente-
narians were retested after a relatively shorter time. The rel-
atively low stability of centenarians might point to a higher
level of vulnerability as social and psychological resources
diminish (Martin et al., 1996). In any case, our results may
for the first time provide some indication that personality
becomes more fluid and prone to change at the extreme end
of the human life span (Costa et al., 1980). This late-in-life
change may be due to the fact that centenarians are getting
closer to the end of their lives, to increased fatigue, or to
cognitive changes late in life. The last interpretation would
also suggest that a larger number of response errors in cen-
tenarians at the second measurement time could account for
lower stability.
To test the hypothesis that cognitive functioning may ac-
count for lower stability scores in centenarians at the second
measurement point, we divided the centenarian survivors
into two smaller subgroups: those with a relatively high
score on the MMSE and those with a relatively low score.
Lower stabilities for cognitively impaired centenarians may
merely reflect the inability to comprehend questions. The
results indicated that trait stability is not significantly higher
in centenarians with high mental-status scores. Personality-
state stability was actually higher in centenarians with rela-
tively low scores on the mental status test. Particularly, the
Guilt and Arousal dimensions, as well as Radicalism and
Tension for personality traits, turned out to be high for cen-
tenarians with low mental-status scores, although stability
differences were only significant for Radicalism and Ten-
sion. Taken together, the results suggest that personality
states and traits stabilities do not uniformly decline as a
function of increased cognitive impairment, but may con-
centrate around a few specific traits and states, such as Rad-
icalism and Tension (as traits) and Guilt and Arousal (as
states). If this finding can be replicated with larger samples,
then persistent feelings of guilt and arousal may be found to
relate to mental-status decline.
We also wish to point out that assessing traits and states
conjointly is important when considering personality stabil-
ity and change (Adkins et al., 1996). Items on trait question-
naires are designed to capture stability over time. For exam-
ple, the response to the trait statement “I have been let down
by my friends” (measured on a scale from hardly ever to
quite a lot) as a measure of emotional stability may not
change much over time, whereas the response to the state
statement “Physically I feel tired or full of energy” as a

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Acknowledgment
Address correspondence to Peter Martin, Gerontology Program, Iowa
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Accepted December 8, 2000
Decision Editor: Toni C. Antonucci, PhD