Journal of Youth and Adolescence, Vol. 19, No. 3, 1990
Continuity of Type A Behavior During Childhood, Preadolescence, and Adolescence Liisa Keltikangas-J~irvinen ~ Received February 9, 1989; accepted May 3, 1990
The continuity o f Type A behavior during childhood, preadolescence, and adolescence was studied in 1403 randomly selected children. The subjects" Type A behavior was evaluated by their mothers and also self-rated by preadolescents and adolescents using the A F M S (Type A Behavior for the Finnish Multicenter Study) questionnaire, which is a method based on the Matthews Youth Test for Health and the Swedish version of the Jenkins Activity Survey. The results showed that when mothers" assessments were used, Type A behavior was very highly and homotypically stable during the periods studied, and there were no sex- and age-related differences. Among the different components of Type A pattern, "impatience-aggression" exhibited slightly greater stability than "leadership-sense o f responsibility. " Mothers" assessments had predictive significance in the self-ratings given three years later, especially in girls, while the continuity of the self-ratings over adolescence was rather low.
INTRODUCTION
Cardiovascular diseases constitute the principal causes of mortality in middle-aged men in most industrialized countries (e.g., Dembroski and Costa, 1987). Alongside the traditional risk factors such as elevated blood pressure, cigarette smoking, and elevated cholesterol, Type A behavior pattern has been shown to be related to both coronary atherosclerosis (Blumenthal
1Acting Professor, Department of Psychology, University of Helsinki, 0010 Helsinki, Fabianinkatu 8, Finland. Received Ph.D. from University of Helsinki. Research interests: psychosomatics, behavioral medicine and social development of a child. 221 0047-2891/90/0600-0221506.00/0 9 1990PlenumPublishingCorporation
222
Keltikangas-Jiirvinen
et al., 1978; Friedman et al., 1968; Williams et al., 1980; Zyzanski et ai., 1976) and coronary heart disease (CHD); Haynes et al., 1980; Rosenman et al., 1975). Type A behavior has been characterized by a tendency toward competitiveness, time urgency, impatience, hostility, irritability, and speed of activity. Despite an increasing skepticism toward the role of the Type behavior (e.g., Case et al., 1975; Shekelle et al., 1985a; ShekeUe et al., 1985b), the evidence of a causal association between this behavioral pattern and CHD has been so convincing that intervention strategies for that risk behavior have been planned (see Jenkins, 1987). There are, however, several questions to answer. It is known that the development of coronary artery disease (CAD) may begin during childhood (Wolf et al., 1981). Type A behavior has even been identified in 3-year-old children (Lundberg, 1983). Consequently, the early prevention of risk behavior is clearly important. However, as Steinberg (1986) has stressed, "demonstrating that there exist Type A children is one thing, demonstrating that these children grow up to be Type A adults is quite another". So the continuity of Type A behavior pattern across different developmental stages is an important issue for further research. Matthews and Avis (1983) reported that an overt Type A behavior assessed via the Matthews Youth Test for Health is relatively stable over oneyear intervals during the elementary school. Their study, however, does not establish the stability of Type A behavior over a period of time during which changes in the form or expression of such behavior might be expected to occur. Two longitudinal studies to date have followed the stability of components of Type A behavior pattern over the developmental stages: from childhood to adulthood by Steinberg (1986) and from adolescence to adulthood by Bergman and Magnusson (1986). In Steinberg's study Type A behavior was divided into three components, namely achievement-striving, competitiveness, and impatience-anger, and they were evaluated on the basis of interviews conducted with the elementary school teacher during the subject's childhood and with his peers during the subject's adolescence. The results showed that components of Type A behavior were not very stable over the childhood to adolescence years. It might be asked what effect the method of deriving data has on these results. Unfortunately, no previous study exists where Type A behavior has been followed over developmental periods using the same method in different phases. The purpose of the present study was to examine the continuity of Type A behavior during childhood, preadolescence, and adolescence, Type A behavior being measured with the same method in all developmental phases. In addition to the global score of Type A behavior, the continuity of its different dimensions was evaluated, because an examination of the different components of Type A has been recently seen as a more profitable research strategy than an assessment of the global score.
Continuity of Type A Behavior
223 METHOD
Subjects
The subjects were 1403 randomly selected Finnish children and their mothers. They comprised the fixed age cohorts of the Finnish Multicenter Study, which is a prospective study on atherosclerosis precursors in childhood and adolescence.
Selection of Subjects The subjects for the Finnish Multicenter Study were selected on the basis of the Social Insurance Institution's population register, which covers the whole population of Finland. F r o m that register, the children in the 3-, 6-, 9-, 12-, 15-, and 18-year-old cohorts and living in the area of five university cities with medical schools were separately placed in r a n d o m order on the basis of their social security number. Then a r a n d o m sample of 60 boys and 60 girls were selected in each age cohort in every area. The subjects of the present study were the children of 6-, 9-, and 12-year-old cohorts of the former mentioned study. They were originally 1800 children f r o m w h o m a total of 1616 and their mothers were available to participate in the first study. F r o m them, a total of 1403 children and their mothers were contactable for the follow-up study, three years later. Only subjects (1403) and their mothers who had participated in both studies were included in the present study. In regard to the demographic variables as well as somatic risk variables of C H D , the sample of the follow-up study was representative of the sample of the first study. In the first study, the subjects were divided into the following developmental stages: early childhood (6-year-olds), later childhood (9-year-olds), and preadolescence (12-year-olds). The number of subjects in different age groups are seen in Table I.
Table L Subjects of the Present Study
First testing
Second testing
Age 6
Sex Boys Girls
N 280 282
Age Sex 9 Boys Girls
N 256 244
9
Boys Girls
240 240
12 Boys Girls
201 238
12
Boys Girls 1616
293 281
15 Boys Girls
231 233 1403
Total
224
Keltikangas-Jiirvinen Measurement
Type A behavior of the subjects was measured using the AFMS questionnaire (Type A behavior for the finnish Multicenter Study). The AFMS consists of 17 five-choice items and it is a combination from the Matthews Youth Test for Health (MYTH; Matthews and Angulo, 1980) and from the Swedish version of the Jenkins Activity Survey for students (JAS; Lundberg, 1980). Items of the AFMS are given in Appendix 1. Details of the construction of the test has been presented by Keltikangas-Jarvinen (1989). Its reliability and validity have been shown to be high (Keltikangas-J~irvinen and Jokinen, 1989; Keltikangas-J/irvinen and R~iikkfnen, 1989). Different Type A measures appear to tap different Type A components (Matthews et al., 1982). Therefore, the need for using multiple measures has been stressed (e.g., Heft et al., 1988). Due to practical reasons (i.e., the multifactorial nature of the Finnish Multicenter study) this was not possible in the present study. However, self-ratings and judgments of mothers were available, and this combination has been found to be very appropriate in children (Heft et al., 1988). Procedure
In the first time, Type A behavior of the subjects was evaluated by the mothers and 12-years-olds also assessed themselves. In the second time, evaluations of the mothers were adopted in each age group, and in addition, selfratings were used in groups of 12- and 15-year-olds. So the following problems could be studied: (a) continuity of the mothers' assessments, (b) predictive significance of the mothers' assessments for the self-ratings three years later, (c) continuity of self-ratings (only during adolescence), and (d) agreement among different methods (only in preadolescence and adolescence). The children completed the AFMS questionnaire in connection with the medical examinations of the Finnish Multicenter Study while the AFMS was mailed to their mothers, who filled them in at home.
RESULTS The means and standard deviations of the AFMS are given in Table II. They show that the boys are likely to score higher on Type A behavior than the girls, although the differences are not always statistically significant. Two by two analyses of variance were computed for each age cohort, with sex as a between-subjects factor and testing time as a repeated-measures factor.
225
Continuity of Type A Behavior Table II. Means and Standard Deviations of Type A Behavior Type A behavior First testing Sex
Age
Self-rated
Assessed by mothers
Second testing Age
Self-rated
Assessed by mothers
Boys Girls
6
46.0 +__ 8.4 46.9 _+ 8.2
9
Boys Girls
9
47.3 + 13.0 44.6 _+ 7.4
12
46.8 + 7.2 45.4 _+ 8.1
47.0 + 7.1 46.3 + 7.8
12 46.2 + 13.4 46.6 + 13.4 47.2 +_ 8 . 2 47.4 • 8.4
15
47.2 + 8.2 46.1 • 7.2
47.4 _ 8.4 47.2 • 7.4
Boys Girls
45.0 _ 7.4 47.0 • 8.6
The results showed that age and sex had statistically significant main effects in the group of 9-year-old children (Type A behavior was assessed by mothers): the boys scored higher than the girls (F = 55.51, p < .01), but during the follow-up period (between the years 12-15) the scores increased significantly for the girls but not for the boys (F = 4.41,p < .03). During the second developmental period (between the years 12-15) the increase in Type A scores was also almost significant among the girls but not among the boys. Factor analysis (principal component method, varimax rotation) was computed in each age group. The eigenvalues dropped steeply after two factors in each subgroup, and a two-factor solution was adopted. Total variance explained by those factors was on average 57~ in the different groups (range 52-68070). Factor analyses, both for self-ratings and for mothers' assessments, resulted for every group on two identical factors, which were labeled "impatience-aggression" and "leadership-sense of responsibility." The original factor structure of the MYTH remained. The impatience-aggression factor was identical to that for the original MYTH (Matthews and Angulo, 1980). The leadership-sense of responsibility factor comprised the items of the "competitiveness" factor from the original MYTH plus the items derived from the JAS. Details of the factors are given by Keltikangas-J~irvinen and R~iikk6nen (1989). The four main points that the study set out to analyze are as follows: 1. Continuity of the Mothers' Assessments
The stability of Type A behavior is rather high in each subgroup, with correlations between .48 and .58. There are no systematic age- or sex-related
Kelfikangas-Jiirvinen
226
Table I l L Stability a n d P r e d i c t i v e Significance o f M o t h e r s ' A s s e s s m e n t s
(Pearson's r)a Global score Period 6-9 9-12 12-15
Sex
(1)
Boys Girls Boys Girls Boys Girls
.50 d .58 d .55 a .57 a .49 a .48 a
Impatienceaggression
(2)
(1)
.29 c .36 a .28 r .36 d
.54 a .58 d .57 d .58 a .58 a .58 a
Leadershipsense of responsibility
(2)
(1)
(2)
.17 b .30 ~ .36 d .36 a
.29 a .36 a .45 a .50 a .47 a .47 d
.18 b .29 r .32 r AI d
a(1) T e s t - r e t e s t s t a b i l i t y o f m o t h e r s ' a s s e s s m e n t s over a t h r e e - y e a r period. (2) Correlations between the mothers' assessments a n d the self-ratings given three years later. bp < .05.
Cp < .01. ap < .001.
differences. As to the different components of the Type A behavior pattern, the stability of the impatience-aggression factor is as high as or a little higher than the stability of the global scores. Again, there are no sex- or age-related differences. Correlations showing the stability of the leadership-sense of responsibility component were statistically significant, although they were a little lower than those showing the stability of the impatience-aggression factor. The lowest correlations were found among the youngest children (Table III). 2. Predictive Significance of the Mothers's Assessments for the Self-Ratings Correlations showing the predictive significance of the mothers' assessments were not very high, although they were statistically significant in each subgroup. Correlations were slightly higher for girls. As to the different components of the Type A behavior, the assessments of the mothers had a predictive significance for the later self-ratings, with the exception of 12-year-old boys (9-year-olds when they were assessed by their mothers; Table III). 3. Continuity of the Self-Ratings During Adolescence The continuity of self-ratings was statistically significant in boys but not in girls. Concerning the different components, impatience-aggression was
227
Continuity of Type A Behavior Table IV. Stability of Self-Ratings (Pearson's r)
Period
Sex
Global score
12-15
Boys Girls
.28b .19"
LeadershipImpatiencesense of aggression responsibility .43~ .21~
.27" .16"
"p < .05. ~p < .01.
Cp < .001.
m o r e stable t h a n leadership-sense o f responsibility a n d it was m o r e stable in boys t h a n in girls (Table IV).
4. Agreement A m o n g the Self-Ratings and the Mothers' Assessments in Preadolescence and Adolescence W h e n only the g r o u p o f 12-year-old children was available the c o n c u r rent correlation was rather low in the first series o f tests, b u t in the followu p study when groups o f 12-year-old a n d 15-year-old children were available the a g r e e m e n t was very high. I n girls, the c o r r e l a t i o n s b o t h for global scores a n d for the different c o m p o n e n t s were significant at the level p < .001, the lowest c o r r e l a t i o n for b o t h global scores a n d the different c o m p o n e n t s being .52. T h e correlations for boys were also statistically significant b u t lower t h a n those for the girls. F o r boys, the correlations for the impatience-aggression factor were as high as those for girls, b u t the correla-
Table V. Agreement Between Different Ratings (Pearson's r)
First testing Second testing
Period
Sex
12-15
Boys Girls
.19" .15"
.27" .17"
.27" .12"
9-12
Boys Girls Boys Girls
.34b .54c .30b .70c
.44c .52c .49c .59c
.28b .58c .31b .55c
12-15 "p < .05. bp < .01.
~p < .001.
LeadershipImpatiencesense of aggression responsibility
Global score
228
Keltikangas4irvinen
tions for the global scores and for the leadership-sense o f responsibility factor were on average .30 as opposed to .55-.70 for girls (Table V). Type A behavior has been viewed here as a dimension. Some researchers, such as Matthews (1982), think that Type A behavior should not be treated as a trait variable but as a typology since there are qualitative as well as quantitative differences between Type A and Type B behavior. Consequently, subjects were classified into Type A and Type B groups on the basis of median splits within the boys' and girls' subsamples for each age, and the stability of this classification was studied with tetrachoric correlations (Table VI). Median splits were used because the proportion of Type A behavior in the general population has been reported to be from 50% to 75% (Moss et al., 1986). Results indicated that the stability o f Type A - T y p e B typology based on the mothers' assessments remained the same or was slightly higher than the stability of Type A treated as a continuous variable. Classifications based on the self-ratings showed no significant stability.
DISCUSSION The results do not answer the question as to whether Type A children grow up to be Type A adults, but they do show that Type A children grow up to be Type A preadolescents and Type A preadolescents retain their behavior pattern at least throughout adolescence. The results may indicate that the findings o f Steinberg (1986) have suffered from the fact that measures in different phases of the study had been derived from different sources; when the same method was applied at all stages, stability was found not only in Table VI. Tetrachoric Correlations Showinga Stability of Type A-Type
B Typology During a Three-Year Perioda
Sex Boys Girls Boys Girls Boys Girls
First testing 6
Age Second testing 9
Type A self-rated r (1) ---
9
12
--
-
12
15
.28c .13
(34%) (19%)
Assessed by mothers r (1) .45 d (65%) .57 d (68%) .59a (70%) .53a (70%) .60 d
(700"/0)
.50a
(66%)
*(1) Percent of the subjects being classified as Type As in the first testing and retaining their scores in the second testing. ~p < .05.
~p < .01. dp < .0ol.
Continuity of Type A Behavior
229
adolescence but, and this is in conflict with the results of Steinberg, also in childhood. The degree of stability was very high and similar over different developmental periods. The factor structure of Type A behavior also remained the same over childhood, preadolescence, and adolescence and the stability of the different components also remained high. This suggests that the Type A behavior pattern is likely to be homotypically stable throughout childhood, preadolescence, and adolescence, that is, its observable manifestation is similar across different developmental stages. Homotypical stability has been assumed in the previous research but there has been very little empirical evidence to support this assumption. Steinberg's finding that Type A behavior is heterotypically stable-i.e., its manifestations are dissimilar at different developmental periods, so that it may begin to stabilize sometime between middle childhood and early adolescence and may become increasingly stable over t i m e - m i g h t be due to the method of deriving data from different sources. Compared with previous studies, Matthews and Avis (1983) found that Type A behavior was less stable in boys than in girls, but in other settings they found the results were similar for boys and girls. Steinberg (1986) showed that stability was somewhat higher in boys than in girls. The present results do not reveal any sex-related difference. What was found to be more important was the component studied: the stability of the impatience-aggression components was slightly higher than that of leadership-sense of responsibility. The predictive significance of the mothers' assessments as well as the agreement among self-ratings and mothers' assessments were slightly higher for girls than for boys. It may be that the mothers knew their daughters better than they knew their sons and the mothers' evaluations were therefore more reliable for girls than for boys. A further speculation is that the girls expressed a stronger mirroring, i.e., their self-concepts (expressed in the self-ratings) reflected their mothers' opinion of them. Conclusions concerning the stability of the self-ratings must be drawn with caution because only one age group was available. The results may, however, indicate that an individual's self-concept changes so much during adolescence that the self-ratings in preadolescence have a rather low predictive significance. It is difficult to find any reasonable explanation for the low concurrent correlation between the self-ratings and the assessments of the mothers in the first testing but a high one in the follow-up study. Because there was only one age group (a group of 12-year-olds) in the first testing, and because this group, along with the later 12-year-old group, expressed high correlation in the second testing time, the low agreement in the first test may be seen as a matter of chance. The concurrent correlation between the different methods was high for the impatience-aggression factor, both in girls and boys, while the correla-
230
Keltikangas-Jirvinen
t i o n for the leadership-sense o f responsibility factor was high in girls b u t low in boys. This explains the higher c o r r e l a t i o n for the global score in girls. T h e present results show a rather high stability i n T y p e A behavior, especially i n the i m p a t i e n c e - a g g r e s s i o n c o m p o n e n t . It has recently been suggested that this c o m p o n e n t is the very risk factor in the d e v e l o p m e n t o f C H D in adults (Jenkins, 1987). Similarly, it has b e e n s h o w n that in adolescents, this factor correlates with the somatic risk factors o f C H D (KeltikangasJ~irvinen a n d R ~ i k k 6 n e n , 1989). So the results might suggest the desirability o f the early p r e v e n t i o n o f the i m p a t i e n c e - a g g r e s s i o n c o m p o n e n t o f Type A p a t t e r n . H o w e v e r , before preventive p r o g r a m s can be considered, the link between child a n d a d u l t b e h a v i o r p a t t e r n as well as the link between i m p a t i e n c e - a g g r e s s i o n a n d c a r d i o v a s c u l a r diseases m u s t be b e t t e r documented.
REFERENCES Bergman, L. R., and Magnusson, D. (1986). Type A behavior: A longitudinal study from childhood to adulthood. Psychosom. Med. 48: 134-142. Blumenthal, J. A., Williams, R. B., Kong, Y., Schanberg, S. M., and Thompson, L. W. (1978). Type A behavior pattern and coronary atherosclerosis. Circulation 58: 634-639. Case, R. B., Heller, S. S., Case, N. B., and Moss, A. J. 0985). The MulticenterPost-infarction Research Group: Type A behavior and survival after acute myocardial infarction. New Engl. Med. 312: 737-741. Dembroski, T. M., and Costa, P. T. (1987). Coronary prone behavior: components of the Type A pattern and hostility. J. Personal. 55: 213-235. Friedman, M., Rosenman, R. H., Strauss, R., Wurm, M., and Kositchek, R. (1968). The relationship of behavior pattern to the state of the coronary vasculature. A study of 51 autopsy subjects. Am. J. Med. 244: 525-538. Haynes, G. S., Feinleib, M., and Kannel, W. B. (1980). The relationship of psychosocial factors to coronary heart disease in the Framingham Study: III. Eight-yearincidenceof coronaryheart disease. Am. J. Epidemiol. III: 37-58. Heft, L., Thoresen, C., Kirmil-Gray,K., Wiedenfeld, S., Eagleston, J., Bracke, P., and Arnow, B. (1988). Emotional and temperamental Correlates of Type A in children and adolescents. J. Youth Adoles. 17: 461-475. Jenkins, C. D. (1987). Behavioral risk factors in coronary artery disease. Ann. Rev. Med. 29: 543-562. Keltikangas-J[irvinen,L. (1989). Stability of Type A behavior during adolescence, young adulthood and adulthood. J. Behav. Med. 12: 387-396. Keltikangas-J/irvinen, L., and Jokinen, J. (1989). Type A behavior, coping mechanisms and emotions related to somatic risk factors of coronary heart disease in adolescents. J. Psychosom. Res. 33: 17-27. Keltikangas-J~vinen, L., and R/fikk6nen, K. (1989). Pathogenic and protective factors of Type A behavior in adolescents. J. Psychosom. Res. 33: 591-602. Lundberg, U. (1980). Type A behavior and its relation to personality variables in Swedish male and female university students. Scand. J. Psychol. 21: 133-138. Lundberg, U. (1983). Note on Type A behavior and cardiovascular response to challenge in 3- to 6-year old children. J. Psychosom. Res. 23: 39-42. Matthews, K. A. (1982). Psychological perspectives on the Type A behavior pattern. Psychol. Bull. 91: 293-323. Matthews, K. A., and Angulo, J. (1980). Measurement of the Type A behavior pattern in children: assessment of children's competitiveness, impatience-anger and aggression. Child Develop. 51: 466-475.
Continuity of Type A Behavior
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Matthews, K. A., and Avis, N. E. (1983). Stability of overt Type A behaviors in children: Results from a one-year longitudinal study. Child Develop. 54: 1507-1512. Moss, G. E., Dielman, T. E., Campanelli, P. C., Leech, S. L., Harlan,, W. R., and Horvath, J. W. (1986). Demographic Correlates of SI assessments of Type A behavior. Psychosom. Med. 48: 564-574. Roseman, R. H., Brand, R. J., Jenkins, C. D., Friedman, M., Strauss, R., and Wurm, M. (1975). Coronary heart disease in the Western Colloborative Group Study: Final followup experience of 81/2 years. JAMA 238: 872-877. Shekelle, R. B., Gale, M., and Norusis, M. (1985a). The Aspirin Myocardial Infarction Study Research Group. Type A score (Jenkins Activity Survey) and risk of recurrent coronary heart disease in the aspirin myocardial infarction study. Am. J. Cardiol. 56: 221-225. Shekelle, R. B., Hulley, S. B., Neaton, J. D., Billings, J. H., Borhani, N. O., Gerace, T. A., Jacobs, D. R., Lasser, N. L., Mittlemark, M. B., and Stamler, J. (1985b). The MRFIT behavior pattern study II. Type A behavior and incidence of coronary heart disease. Am. J. Epidemiol. 122: 559-570. Steinberg, L. (1986). Stability (and instability) of Type A behavior from childhood to young adulthood. Dev. Psychol. 22: 393-402. Tarkkonen, L. (1987). On Reliability o f Composite Scales. Finnish Statistical Society, Helsinki. Williams, R. B., Haney, T. L., Lee, K. L., Kong, Y., Blumenthal, J. A., and Whalen, R. E. (1980). Type A behavior, hostility, and coronary atherosclerosis. Psychosom. Med. 42: 539-549. Wolf, T. M., Hunter, S. MacD., Webber, L. S., and Berenson, G. A. (1981). Self-concept, locus of control, goal blockage and coronary prone behavior pattern in children and adolescents: Bogalusa Heart study. J. Gen. Psychol. 105: 13-26. Zyzanski, S. J., Jenkins, C. D., Ryan, T. J., Flessas, A., and Everist, M. (1976). Psychological correlates of coronary angiographic findings. Arch. Int. Med. 136: 1234-1237.
APPENDIX 1 The Items o f the A F M S The AFMS consists of the following items:
MYTH I work quickly and energetically rather than slowly and deliberately. When I have to wait for others I become impatient. I do things in a hurry. I interrupt others. I am leader in various activities. I get easily irritated. I like to argue or debate. When working or playing I try to do better than other children. I cannot sit still long. It is important to me to win rather than to have fun in games or schoolwork. Other children look to me for leadership. I am hard-driving and competitive. I tend to get into fights.
JAS I experience a lot of enjoyment of life. I consider myself more responsible than the average student.
232
Keltikangas-J~irvinen I am rated by m y friends to be too active. I approach life m u c h more seriously than the average child.
Continuity of Type A Behavior During Childhood, Preadolescence, and Adolescence Liisa Keltikangas-J~irvinen ~ Received February 9, 1989; accepted May 3, 1990
The continuity o f Type A behavior during childhood, preadolescence, and adolescence was studied in 1403 randomly selected children. The subjects" Type A behavior was evaluated by their mothers and also self-rated by preadolescents and adolescents using the A F M S (Type A Behavior for the Finnish Multicenter Study) questionnaire, which is a method based on the Matthews Youth Test for Health and the Swedish version of the Jenkins Activity Survey. The results showed that when mothers" assessments were used, Type A behavior was very highly and homotypically stable during the periods studied, and there were no sex- and age-related differences. Among the different components of Type A pattern, "impatience-aggression" exhibited slightly greater stability than "leadership-sense o f responsibility. " Mothers" assessments had predictive significance in the self-ratings given three years later, especially in girls, while the continuity of the self-ratings over adolescence was rather low.
INTRODUCTION
Cardiovascular diseases constitute the principal causes of mortality in middle-aged men in most industrialized countries (e.g., Dembroski and Costa, 1987). Alongside the traditional risk factors such as elevated blood pressure, cigarette smoking, and elevated cholesterol, Type A behavior pattern has been shown to be related to both coronary atherosclerosis (Blumenthal
1Acting Professor, Department of Psychology, University of Helsinki, 0010 Helsinki, Fabianinkatu 8, Finland. Received Ph.D. from University of Helsinki. Research interests: psychosomatics, behavioral medicine and social development of a child. 221 0047-2891/90/0600-0221506.00/0 9 1990PlenumPublishingCorporation
222
Keltikangas-Jiirvinen
et al., 1978; Friedman et al., 1968; Williams et al., 1980; Zyzanski et ai., 1976) and coronary heart disease (CHD); Haynes et al., 1980; Rosenman et al., 1975). Type A behavior has been characterized by a tendency toward competitiveness, time urgency, impatience, hostility, irritability, and speed of activity. Despite an increasing skepticism toward the role of the Type behavior (e.g., Case et al., 1975; Shekelle et al., 1985a; ShekeUe et al., 1985b), the evidence of a causal association between this behavioral pattern and CHD has been so convincing that intervention strategies for that risk behavior have been planned (see Jenkins, 1987). There are, however, several questions to answer. It is known that the development of coronary artery disease (CAD) may begin during childhood (Wolf et al., 1981). Type A behavior has even been identified in 3-year-old children (Lundberg, 1983). Consequently, the early prevention of risk behavior is clearly important. However, as Steinberg (1986) has stressed, "demonstrating that there exist Type A children is one thing, demonstrating that these children grow up to be Type A adults is quite another". So the continuity of Type A behavior pattern across different developmental stages is an important issue for further research. Matthews and Avis (1983) reported that an overt Type A behavior assessed via the Matthews Youth Test for Health is relatively stable over oneyear intervals during the elementary school. Their study, however, does not establish the stability of Type A behavior over a period of time during which changes in the form or expression of such behavior might be expected to occur. Two longitudinal studies to date have followed the stability of components of Type A behavior pattern over the developmental stages: from childhood to adulthood by Steinberg (1986) and from adolescence to adulthood by Bergman and Magnusson (1986). In Steinberg's study Type A behavior was divided into three components, namely achievement-striving, competitiveness, and impatience-anger, and they were evaluated on the basis of interviews conducted with the elementary school teacher during the subject's childhood and with his peers during the subject's adolescence. The results showed that components of Type A behavior were not very stable over the childhood to adolescence years. It might be asked what effect the method of deriving data has on these results. Unfortunately, no previous study exists where Type A behavior has been followed over developmental periods using the same method in different phases. The purpose of the present study was to examine the continuity of Type A behavior during childhood, preadolescence, and adolescence, Type A behavior being measured with the same method in all developmental phases. In addition to the global score of Type A behavior, the continuity of its different dimensions was evaluated, because an examination of the different components of Type A has been recently seen as a more profitable research strategy than an assessment of the global score.
Continuity of Type A Behavior
223 METHOD
Subjects
The subjects were 1403 randomly selected Finnish children and their mothers. They comprised the fixed age cohorts of the Finnish Multicenter Study, which is a prospective study on atherosclerosis precursors in childhood and adolescence.
Selection of Subjects The subjects for the Finnish Multicenter Study were selected on the basis of the Social Insurance Institution's population register, which covers the whole population of Finland. F r o m that register, the children in the 3-, 6-, 9-, 12-, 15-, and 18-year-old cohorts and living in the area of five university cities with medical schools were separately placed in r a n d o m order on the basis of their social security number. Then a r a n d o m sample of 60 boys and 60 girls were selected in each age cohort in every area. The subjects of the present study were the children of 6-, 9-, and 12-year-old cohorts of the former mentioned study. They were originally 1800 children f r o m w h o m a total of 1616 and their mothers were available to participate in the first study. F r o m them, a total of 1403 children and their mothers were contactable for the follow-up study, three years later. Only subjects (1403) and their mothers who had participated in both studies were included in the present study. In regard to the demographic variables as well as somatic risk variables of C H D , the sample of the follow-up study was representative of the sample of the first study. In the first study, the subjects were divided into the following developmental stages: early childhood (6-year-olds), later childhood (9-year-olds), and preadolescence (12-year-olds). The number of subjects in different age groups are seen in Table I.
Table L Subjects of the Present Study
First testing
Second testing
Age 6
Sex Boys Girls
N 280 282
Age Sex 9 Boys Girls
N 256 244
9
Boys Girls
240 240
12 Boys Girls
201 238
12
Boys Girls 1616
293 281
15 Boys Girls
231 233 1403
Total
224
Keltikangas-Jiirvinen Measurement
Type A behavior of the subjects was measured using the AFMS questionnaire (Type A behavior for the finnish Multicenter Study). The AFMS consists of 17 five-choice items and it is a combination from the Matthews Youth Test for Health (MYTH; Matthews and Angulo, 1980) and from the Swedish version of the Jenkins Activity Survey for students (JAS; Lundberg, 1980). Items of the AFMS are given in Appendix 1. Details of the construction of the test has been presented by Keltikangas-Jarvinen (1989). Its reliability and validity have been shown to be high (Keltikangas-J~irvinen and Jokinen, 1989; Keltikangas-J/irvinen and R~iikkfnen, 1989). Different Type A measures appear to tap different Type A components (Matthews et al., 1982). Therefore, the need for using multiple measures has been stressed (e.g., Heft et al., 1988). Due to practical reasons (i.e., the multifactorial nature of the Finnish Multicenter study) this was not possible in the present study. However, self-ratings and judgments of mothers were available, and this combination has been found to be very appropriate in children (Heft et al., 1988). Procedure
In the first time, Type A behavior of the subjects was evaluated by the mothers and 12-years-olds also assessed themselves. In the second time, evaluations of the mothers were adopted in each age group, and in addition, selfratings were used in groups of 12- and 15-year-olds. So the following problems could be studied: (a) continuity of the mothers' assessments, (b) predictive significance of the mothers' assessments for the self-ratings three years later, (c) continuity of self-ratings (only during adolescence), and (d) agreement among different methods (only in preadolescence and adolescence). The children completed the AFMS questionnaire in connection with the medical examinations of the Finnish Multicenter Study while the AFMS was mailed to their mothers, who filled them in at home.
RESULTS The means and standard deviations of the AFMS are given in Table II. They show that the boys are likely to score higher on Type A behavior than the girls, although the differences are not always statistically significant. Two by two analyses of variance were computed for each age cohort, with sex as a between-subjects factor and testing time as a repeated-measures factor.
225
Continuity of Type A Behavior Table II. Means and Standard Deviations of Type A Behavior Type A behavior First testing Sex
Age
Self-rated
Assessed by mothers
Second testing Age
Self-rated
Assessed by mothers
Boys Girls
6
46.0 +__ 8.4 46.9 _+ 8.2
9
Boys Girls
9
47.3 + 13.0 44.6 _+ 7.4
12
46.8 + 7.2 45.4 _+ 8.1
47.0 + 7.1 46.3 + 7.8
12 46.2 + 13.4 46.6 + 13.4 47.2 +_ 8 . 2 47.4 • 8.4
15
47.2 + 8.2 46.1 • 7.2
47.4 _ 8.4 47.2 • 7.4
Boys Girls
45.0 _ 7.4 47.0 • 8.6
The results showed that age and sex had statistically significant main effects in the group of 9-year-old children (Type A behavior was assessed by mothers): the boys scored higher than the girls (F = 55.51, p < .01), but during the follow-up period (between the years 12-15) the scores increased significantly for the girls but not for the boys (F = 4.41,p < .03). During the second developmental period (between the years 12-15) the increase in Type A scores was also almost significant among the girls but not among the boys. Factor analysis (principal component method, varimax rotation) was computed in each age group. The eigenvalues dropped steeply after two factors in each subgroup, and a two-factor solution was adopted. Total variance explained by those factors was on average 57~ in the different groups (range 52-68070). Factor analyses, both for self-ratings and for mothers' assessments, resulted for every group on two identical factors, which were labeled "impatience-aggression" and "leadership-sense of responsibility." The original factor structure of the MYTH remained. The impatience-aggression factor was identical to that for the original MYTH (Matthews and Angulo, 1980). The leadership-sense of responsibility factor comprised the items of the "competitiveness" factor from the original MYTH plus the items derived from the JAS. Details of the factors are given by Keltikangas-J~irvinen and R~iikk6nen (1989). The four main points that the study set out to analyze are as follows: 1. Continuity of the Mothers' Assessments
The stability of Type A behavior is rather high in each subgroup, with correlations between .48 and .58. There are no systematic age- or sex-related
Kelfikangas-Jiirvinen
226
Table I l L Stability a n d P r e d i c t i v e Significance o f M o t h e r s ' A s s e s s m e n t s
(Pearson's r)a Global score Period 6-9 9-12 12-15
Sex
(1)
Boys Girls Boys Girls Boys Girls
.50 d .58 d .55 a .57 a .49 a .48 a
Impatienceaggression
(2)
(1)
.29 c .36 a .28 r .36 d
.54 a .58 d .57 d .58 a .58 a .58 a
Leadershipsense of responsibility
(2)
(1)
(2)
.17 b .30 ~ .36 d .36 a
.29 a .36 a .45 a .50 a .47 a .47 d
.18 b .29 r .32 r AI d
a(1) T e s t - r e t e s t s t a b i l i t y o f m o t h e r s ' a s s e s s m e n t s over a t h r e e - y e a r period. (2) Correlations between the mothers' assessments a n d the self-ratings given three years later. bp < .05.
Cp < .01. ap < .001.
differences. As to the different components of the Type A behavior pattern, the stability of the impatience-aggression factor is as high as or a little higher than the stability of the global scores. Again, there are no sex- or age-related differences. Correlations showing the stability of the leadership-sense of responsibility component were statistically significant, although they were a little lower than those showing the stability of the impatience-aggression factor. The lowest correlations were found among the youngest children (Table III). 2. Predictive Significance of the Mothers's Assessments for the Self-Ratings Correlations showing the predictive significance of the mothers' assessments were not very high, although they were statistically significant in each subgroup. Correlations were slightly higher for girls. As to the different components of the Type A behavior, the assessments of the mothers had a predictive significance for the later self-ratings, with the exception of 12-year-old boys (9-year-olds when they were assessed by their mothers; Table III). 3. Continuity of the Self-Ratings During Adolescence The continuity of self-ratings was statistically significant in boys but not in girls. Concerning the different components, impatience-aggression was
227
Continuity of Type A Behavior Table IV. Stability of Self-Ratings (Pearson's r)
Period
Sex
Global score
12-15
Boys Girls
.28b .19"
LeadershipImpatiencesense of aggression responsibility .43~ .21~
.27" .16"
"p < .05. ~p < .01.
Cp < .001.
m o r e stable t h a n leadership-sense o f responsibility a n d it was m o r e stable in boys t h a n in girls (Table IV).
4. Agreement A m o n g the Self-Ratings and the Mothers' Assessments in Preadolescence and Adolescence W h e n only the g r o u p o f 12-year-old children was available the c o n c u r rent correlation was rather low in the first series o f tests, b u t in the followu p study when groups o f 12-year-old a n d 15-year-old children were available the a g r e e m e n t was very high. I n girls, the c o r r e l a t i o n s b o t h for global scores a n d for the different c o m p o n e n t s were significant at the level p < .001, the lowest c o r r e l a t i o n for b o t h global scores a n d the different c o m p o n e n t s being .52. T h e correlations for boys were also statistically significant b u t lower t h a n those for the girls. F o r boys, the correlations for the impatience-aggression factor were as high as those for girls, b u t the correla-
Table V. Agreement Between Different Ratings (Pearson's r)
First testing Second testing
Period
Sex
12-15
Boys Girls
.19" .15"
.27" .17"
.27" .12"
9-12
Boys Girls Boys Girls
.34b .54c .30b .70c
.44c .52c .49c .59c
.28b .58c .31b .55c
12-15 "p < .05. bp < .01.
~p < .001.
LeadershipImpatiencesense of aggression responsibility
Global score
228
Keltikangas4irvinen
tions for the global scores and for the leadership-sense o f responsibility factor were on average .30 as opposed to .55-.70 for girls (Table V). Type A behavior has been viewed here as a dimension. Some researchers, such as Matthews (1982), think that Type A behavior should not be treated as a trait variable but as a typology since there are qualitative as well as quantitative differences between Type A and Type B behavior. Consequently, subjects were classified into Type A and Type B groups on the basis of median splits within the boys' and girls' subsamples for each age, and the stability of this classification was studied with tetrachoric correlations (Table VI). Median splits were used because the proportion of Type A behavior in the general population has been reported to be from 50% to 75% (Moss et al., 1986). Results indicated that the stability o f Type A - T y p e B typology based on the mothers' assessments remained the same or was slightly higher than the stability of Type A treated as a continuous variable. Classifications based on the self-ratings showed no significant stability.
DISCUSSION The results do not answer the question as to whether Type A children grow up to be Type A adults, but they do show that Type A children grow up to be Type A preadolescents and Type A preadolescents retain their behavior pattern at least throughout adolescence. The results may indicate that the findings o f Steinberg (1986) have suffered from the fact that measures in different phases of the study had been derived from different sources; when the same method was applied at all stages, stability was found not only in Table VI. Tetrachoric Correlations Showinga Stability of Type A-Type
B Typology During a Three-Year Perioda
Sex Boys Girls Boys Girls Boys Girls
First testing 6
Age Second testing 9
Type A self-rated r (1) ---
9
12
--
-
12
15
.28c .13
(34%) (19%)
Assessed by mothers r (1) .45 d (65%) .57 d (68%) .59a (70%) .53a (70%) .60 d
(700"/0)
.50a
(66%)
*(1) Percent of the subjects being classified as Type As in the first testing and retaining their scores in the second testing. ~p < .05.
~p < .01. dp < .0ol.
Continuity of Type A Behavior
229
adolescence but, and this is in conflict with the results of Steinberg, also in childhood. The degree of stability was very high and similar over different developmental periods. The factor structure of Type A behavior also remained the same over childhood, preadolescence, and adolescence and the stability of the different components also remained high. This suggests that the Type A behavior pattern is likely to be homotypically stable throughout childhood, preadolescence, and adolescence, that is, its observable manifestation is similar across different developmental stages. Homotypical stability has been assumed in the previous research but there has been very little empirical evidence to support this assumption. Steinberg's finding that Type A behavior is heterotypically stable-i.e., its manifestations are dissimilar at different developmental periods, so that it may begin to stabilize sometime between middle childhood and early adolescence and may become increasingly stable over t i m e - m i g h t be due to the method of deriving data from different sources. Compared with previous studies, Matthews and Avis (1983) found that Type A behavior was less stable in boys than in girls, but in other settings they found the results were similar for boys and girls. Steinberg (1986) showed that stability was somewhat higher in boys than in girls. The present results do not reveal any sex-related difference. What was found to be more important was the component studied: the stability of the impatience-aggression components was slightly higher than that of leadership-sense of responsibility. The predictive significance of the mothers' assessments as well as the agreement among self-ratings and mothers' assessments were slightly higher for girls than for boys. It may be that the mothers knew their daughters better than they knew their sons and the mothers' evaluations were therefore more reliable for girls than for boys. A further speculation is that the girls expressed a stronger mirroring, i.e., their self-concepts (expressed in the self-ratings) reflected their mothers' opinion of them. Conclusions concerning the stability of the self-ratings must be drawn with caution because only one age group was available. The results may, however, indicate that an individual's self-concept changes so much during adolescence that the self-ratings in preadolescence have a rather low predictive significance. It is difficult to find any reasonable explanation for the low concurrent correlation between the self-ratings and the assessments of the mothers in the first testing but a high one in the follow-up study. Because there was only one age group (a group of 12-year-olds) in the first testing, and because this group, along with the later 12-year-old group, expressed high correlation in the second testing time, the low agreement in the first test may be seen as a matter of chance. The concurrent correlation between the different methods was high for the impatience-aggression factor, both in girls and boys, while the correla-
230
Keltikangas-Jirvinen
t i o n for the leadership-sense o f responsibility factor was high in girls b u t low in boys. This explains the higher c o r r e l a t i o n for the global score in girls. T h e present results show a rather high stability i n T y p e A behavior, especially i n the i m p a t i e n c e - a g g r e s s i o n c o m p o n e n t . It has recently been suggested that this c o m p o n e n t is the very risk factor in the d e v e l o p m e n t o f C H D in adults (Jenkins, 1987). Similarly, it has b e e n s h o w n that in adolescents, this factor correlates with the somatic risk factors o f C H D (KeltikangasJ~irvinen a n d R ~ i k k 6 n e n , 1989). So the results might suggest the desirability o f the early p r e v e n t i o n o f the i m p a t i e n c e - a g g r e s s i o n c o m p o n e n t o f Type A p a t t e r n . H o w e v e r , before preventive p r o g r a m s can be considered, the link between child a n d a d u l t b e h a v i o r p a t t e r n as well as the link between i m p a t i e n c e - a g g r e s s i o n a n d c a r d i o v a s c u l a r diseases m u s t be b e t t e r documented.
REFERENCES Bergman, L. R., and Magnusson, D. (1986). Type A behavior: A longitudinal study from childhood to adulthood. Psychosom. Med. 48: 134-142. Blumenthal, J. A., Williams, R. B., Kong, Y., Schanberg, S. M., and Thompson, L. W. (1978). Type A behavior pattern and coronary atherosclerosis. Circulation 58: 634-639. Case, R. B., Heller, S. S., Case, N. B., and Moss, A. J. 0985). The MulticenterPost-infarction Research Group: Type A behavior and survival after acute myocardial infarction. New Engl. Med. 312: 737-741. Dembroski, T. M., and Costa, P. T. (1987). Coronary prone behavior: components of the Type A pattern and hostility. J. Personal. 55: 213-235. Friedman, M., Rosenman, R. H., Strauss, R., Wurm, M., and Kositchek, R. (1968). The relationship of behavior pattern to the state of the coronary vasculature. A study of 51 autopsy subjects. Am. J. Med. 244: 525-538. Haynes, G. S., Feinleib, M., and Kannel, W. B. (1980). The relationship of psychosocial factors to coronary heart disease in the Framingham Study: III. Eight-yearincidenceof coronaryheart disease. Am. J. Epidemiol. III: 37-58. Heft, L., Thoresen, C., Kirmil-Gray,K., Wiedenfeld, S., Eagleston, J., Bracke, P., and Arnow, B. (1988). Emotional and temperamental Correlates of Type A in children and adolescents. J. Youth Adoles. 17: 461-475. Jenkins, C. D. (1987). Behavioral risk factors in coronary artery disease. Ann. Rev. Med. 29: 543-562. Keltikangas-J[irvinen,L. (1989). Stability of Type A behavior during adolescence, young adulthood and adulthood. J. Behav. Med. 12: 387-396. Keltikangas-J/irvinen, L., and Jokinen, J. (1989). Type A behavior, coping mechanisms and emotions related to somatic risk factors of coronary heart disease in adolescents. J. Psychosom. Res. 33: 17-27. Keltikangas-J~vinen, L., and R/fikk6nen, K. (1989). Pathogenic and protective factors of Type A behavior in adolescents. J. Psychosom. Res. 33: 591-602. Lundberg, U. (1980). Type A behavior and its relation to personality variables in Swedish male and female university students. Scand. J. Psychol. 21: 133-138. Lundberg, U. (1983). Note on Type A behavior and cardiovascular response to challenge in 3- to 6-year old children. J. Psychosom. Res. 23: 39-42. Matthews, K. A. (1982). Psychological perspectives on the Type A behavior pattern. Psychol. Bull. 91: 293-323. Matthews, K. A., and Angulo, J. (1980). Measurement of the Type A behavior pattern in children: assessment of children's competitiveness, impatience-anger and aggression. Child Develop. 51: 466-475.
Continuity of Type A Behavior
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Matthews, K. A., and Avis, N. E. (1983). Stability of overt Type A behaviors in children: Results from a one-year longitudinal study. Child Develop. 54: 1507-1512. Moss, G. E., Dielman, T. E., Campanelli, P. C., Leech, S. L., Harlan,, W. R., and Horvath, J. W. (1986). Demographic Correlates of SI assessments of Type A behavior. Psychosom. Med. 48: 564-574. Roseman, R. H., Brand, R. J., Jenkins, C. D., Friedman, M., Strauss, R., and Wurm, M. (1975). Coronary heart disease in the Western Colloborative Group Study: Final followup experience of 81/2 years. JAMA 238: 872-877. Shekelle, R. B., Gale, M., and Norusis, M. (1985a). The Aspirin Myocardial Infarction Study Research Group. Type A score (Jenkins Activity Survey) and risk of recurrent coronary heart disease in the aspirin myocardial infarction study. Am. J. Cardiol. 56: 221-225. Shekelle, R. B., Hulley, S. B., Neaton, J. D., Billings, J. H., Borhani, N. O., Gerace, T. A., Jacobs, D. R., Lasser, N. L., Mittlemark, M. B., and Stamler, J. (1985b). The MRFIT behavior pattern study II. Type A behavior and incidence of coronary heart disease. Am. J. Epidemiol. 122: 559-570. Steinberg, L. (1986). Stability (and instability) of Type A behavior from childhood to young adulthood. Dev. Psychol. 22: 393-402. Tarkkonen, L. (1987). On Reliability o f Composite Scales. Finnish Statistical Society, Helsinki. Williams, R. B., Haney, T. L., Lee, K. L., Kong, Y., Blumenthal, J. A., and Whalen, R. E. (1980). Type A behavior, hostility, and coronary atherosclerosis. Psychosom. Med. 42: 539-549. Wolf, T. M., Hunter, S. MacD., Webber, L. S., and Berenson, G. A. (1981). Self-concept, locus of control, goal blockage and coronary prone behavior pattern in children and adolescents: Bogalusa Heart study. J. Gen. Psychol. 105: 13-26. Zyzanski, S. J., Jenkins, C. D., Ryan, T. J., Flessas, A., and Everist, M. (1976). Psychological correlates of coronary angiographic findings. Arch. Int. Med. 136: 1234-1237.
APPENDIX 1 The Items o f the A F M S The AFMS consists of the following items:
MYTH I work quickly and energetically rather than slowly and deliberately. When I have to wait for others I become impatient. I do things in a hurry. I interrupt others. I am leader in various activities. I get easily irritated. I like to argue or debate. When working or playing I try to do better than other children. I cannot sit still long. It is important to me to win rather than to have fun in games or schoolwork. Other children look to me for leadership. I am hard-driving and competitive. I tend to get into fights.
JAS I experience a lot of enjoyment of life. I consider myself more responsible than the average student.
232
Keltikangas-J~irvinen I am rated by m y friends to be too active. I approach life m u c h more seriously than the average child.
