Scand J PsycholJournal Scandinavian 43 (2002)of Psychology, 2002, 43, 61–71
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Temperament in children with Down syndrome and in prematurely born children EGIL NYGAARD1, LARS SMITH2 and ANNE MARI TORGERSEN3 1
Educational Psychological Advisory Service, Bærum Kommune, Norway Institute of Psychology, University of Oslo, Norway 3 Institute of Psychiatry, University of Oslo, Norway 2
Nygaard, E., et al. (2002). Temperament in children with Down syndrome and in prematurely born children. Scandinavian Journal of Psychology, 43, 61–71. Parents of three groups of children completed the Children’s Behavior Questionnaire (CBQ). Participants were children with Down syndrome aged 4–11 years (n = 55), prematurely born children aged 5 years (n = 97), and a group of normally developing kindergarten children 5–7 years of age (n = 91). Mean levels and factor structures on the CBQ were compared between the three groups. The children with Down syndrome had less attentional focusing and expressed less inhibitory control and less sadness than the normally developing children. There were also group differences in temperament structures, especially a clearer emotional factor of “surgency” among the children with Down syndrome. The only significant difference in mean temperament scores between the premature children and the control group was that the former evinced less attentional focussing. The temperament structures in the Norwegian samples were very similar to those reported in earlier studies, conducted in China and the US. Key words: Children’s Behavior Questionnaire, cultural differences, Down syndrome, premature birth, temperament. Egil Nygaard, Harreschousvei 7, 1338 Sandvika, Norway. E-mail:
[email protected]
INTRODUCTION During the past 30 years there has been considerable progress in identifying the broad outlines of temperament in childhood. Temperament is looked upon as a subset of the more general area of personality. It includes basic psychological processes constituting the affective, activational, and attentional core of personality and its development. Temperament is often defined as constitutionally based, influenced by genetic inheritance, maturation, and experience. Temperament influences a person’s behavior and development in several ways. Although there has been considerable progress in identifying the broad outlines of temperament in childhood, there is still need for continuing work on its subdimensions (Rothbart & Bates, 1998). Most work on temperament has been done with normally developing children. However, during the past 20 years researchers have also studied temperament in children with Down syndrome (see Beeghly, 1998; Goldberg & Marcovitch, 1989, for reviews). Most of these studies have reported differences in mean values on various temperamental dimensions between young children with Down syndrome, and either age-matched controls or age norms published by scale developers. Such studies have led to few conclusive answers (Beeghly, 1998). The most reliable group difference is the following: Adults tend to perceive children with Down syndrome as less persistent than normally developing children (Bridges & Cicchetti, 1982; Green, Dennis & Bennets, 1989;
Gunn & Berry, 1985a; Gunn & Berry, 1985b; Gunn & Cuskelly, 1991; Marcovitch, Goldberg, MacGregor & Lojkasek, 1986; Pueschel & Myers, 1994; Ratekin, 1996). Furthermore, children with Down syndrome have been perceived as being either more or less sociable than normal, depending on their age. In infancy they tend to be rated as more difficult than age-matched, normally developing infants, but with increasing age this trend seems to be reversed (Ratekin, 1996). Temperamental differences have also been reported when children with low birth weight and normally developing children have been compared (Field, Hallock, Dempsey & Shuman, 1978; Garcia Coll, Halpern, Vohr, Seifer & Oh, 1992; Gennaro, Medoff-Cooper & Lotas, 1992; Malatesta, Grigoryev, Lamb, Albin & Culver, 1986; Plunkett, Cross & Meisels, 1989; Van Beek, Hopkins & Hoeksma, 1994). Since temperament is related to maturation and general health in infancy (Torgersen, 1985) this is only what one would expect. There are fewer studies of toddlers and preschool children related to this question. Only a few studies have investigated temperament in children with low birth weight above 3 years of age. Some have reported that premature children have a more difficult temperament than full-term children (Howard & Worrell, 1952; Malatesta-Magai, 1991; Minde, Goldberg, Perrotta, Washington, Lojkasek, Corter & Parker, 1989), whereas others have found no difference in global temperamental traits (Pfeiffer & Aylward, 1990). Some (Minde et al., 1989)
© 2002 2002 The Scandinavian Psychological Psychological Associations. Associations. Published by Blackwell Publishers, 108 Cowley Road, Oxford OX4 1JF, UK and 350 Main Street, Malden, MA 02148, USA. ISSN 0036-5564.
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have reported that premature children tend to be more active, whereas others have found the opposite tendency, or no difference at all (Prior, Sanson & Oberklaid, 1989; Wiener, Rider, Oppel, Fischer & Harper, 1965). Children of low birth weight have been reported to be more inhibited and less attentive (Malatesta-Magai, 1991; Minde et al., 1989), but others report no difference in shyness (Grunau, Whitfield & Petrie, 1994), or approach (Prior et al., 1989). These children may have poorer concentration (Minde et al., 1989), and be more impulsive (Wiener et al., 1965), although studies have also reported no differences in distractibility (Wiener et al., 1965) or rhythmicity (Prior et al., 1989). Whereas some researchers are of the opinion that premature children express more negative and less positive emotions (Minde et al., 1989; Prior et al., 1989), others (Grunau, Whitfield, Petrie & Fryer, 1994) have been unable to find any difference in emotionality. The problem with this literature is that for each paper reporting a difference, there exists another study reporting failure to replicate. Differential studies are also hard to compare because different instruments are used to measure temperament. To our knowledge the only study of temperament among premature children above 3 years, using observational data, is Malatesta-Magai’s (1991). Most other investigators have used questionnaires filled out by the parents. There are large differences between the questionnaires in terms of which dimensions are examined, how they are defined, and how many dimensions are examined. Other differences that make it hard to do a comparison include age of the participants, birth weight, whether or not small-for-gestational-age children were included or not, sample size, which instruments were used to measure temperament, and cultural differences. The lack of conclusive findings could also be due to the fact that the existing differences in temperament between premature and full-term children often are quite small, with few measurable behavioral consequences. In most studies of temperament in atypical children the instruments that have been used were developed and standardized on normally developing children. When interpreting the results it is therefore important to be familiar with the underlying structure of the instruments. The Children’s Behavior Questionnaire (CBQ) measures three factors, called “surgency/positive affect”, “negative emotionality”,
and “effortful control”. The 16 subdimensions are assumed to contribute to these three factors in the same way as in the normative sample (Ahadi et al., 1993). For example, if one finds a group difference on the dimension called smiling and laughter, it is important to know whether this difference is related to affect and emotion, or whether it should be associated with attention and control. Correlations between different dimensions may vary across cultures (Ahadi et al., 1993) as well as between different groups of participants. Thus it is important to evaluate the instrument’s validity and reliability on other samples, and in different cultures. To our knowledge no previous studies have explored the factor structure of temperament in children with Down syndrome or among premature children. The aim of the present study was threefold. The first goal was to examine differences seen in children with Down syndrome and premature children, compared with normally developing children, on a large number of temperamental dimensions. By using a broad-scaled instrument the study may contribute to the knowledge of temperamental differences between children with known etiologies compared with normally developing children. Second, the study was designed to compare the factor structure of the CBQ in different groups of participants. Thus light may be thrown on the construct validity and reliability of temperamental factors. A third aim was to explore cultural differences by comparing the factor structure obtained on a Norwegian sample with those found in the US and China.
METHOD Participants Invitations were sent to all parents of children with Down syndrome at aged 4–11 years, who were living in five counties around the city of Oslo, Norway. Of 110 families asked to participate, 55 consented. For ethical reasons, information about the families who did not wish to participate is not available. One participant, who scored more than three standard deviations below the mean on the intelligence test, was excluded (see Table 1 for descriptive statistics). Mean age according to motor ability was 43.8 months (SD 11.3). Sex ratio (26 girls, 29 boys) was as expected (Steele, 1996). In contrast to an expected rate of 20% (National Bureau of Statistics, 1996), 69.8% of the parents held a university degree. This could imply a higher willingness to participate among parents of higher socioeconomic classes, or the rate might be due to a general difference in educational
Table 1. Descriptive statistics of the samples
Number of subjects Mean age in months (SD) Number of girls/boys Proportion of parents with university-level education Mean birth weight (SD)
© 2002 The Scandinavian Psychological Associations.
Children with Down syndrome
Premature children
Normally developing children
55 86.1 (23.4) 26/29 70.4% Not available
97 60.2 (0.56) 48/49 9% 1,124 g (219)
91 Approximately 74 (6) 51/40 Not available Not available
Scand J Psychol 43 (2002) level between urban neighborhoods and rural areas, since most of the participants came from urban areas. A total of 25 children had severe medical complications, including cardiac illness (n = 9), respiratory illness (5), a history of severe infections (2), celiac disease (2), substantial hearing impairment (2), hypothyroidism (2), cataract (1), absent colon (1), and allergies (1). As part of a longitudinal study, children with birth weight below 1501 g were also recruited for the current investigation. Of 112 children (mean birth weight 1124 g, SD 219) who were seen at 3 years (Smith, Ulvund & Lindemann, 1994), one died before the age of 5, and six were lost to follow-up at age 5. Of these 107 parents, 97 returned the temperament questionnaire when the children (48 girls) were 5 years. The parents, who belonged to all socioeconomic levels (Hollingshead, 1957), came from mixed urban, suburban and rural areas, and only 9% held a university degree. A group of normally developing children, who participated in a kindergarten study (Alsaker, unpublished), was also rated on the CBQ by their parents. These children were recruited from 14 daycare groups all located in a stable and socially mixed suburban area near the city of Bergen. Out of 150 invited families, 91 parents completed the CBQ. The children’s ages ranged from 51/2 to 7 years. Information about the exact ages of these children and the socioeconomic status (SES) of their parents was not available.
Instruments The temperament measure used in this study was the CBQ (Ahadi et al., 1993). This is a 195-item questionnaire that provides scores on 16 temperament dimensions. It is a parental report measure on which the parents decide whether a statement about their child is true or untrue on a 7-point scale. Factor analytic studies in the US and China have shown that the CBQ consists of three factors: “surgency/positive affect”, “negative emotionality”, and “effortful control”. The first factor, “surgency/positive affect”, includes positive loadings on the dimensions of activity level, approach, high intensity pleasure, impulsivity, smiling and laughter, and a negative loading for shyness. Positive loadings for anger, discomfort, fear, sadness, and shyness, and a negative loading for falling reactivity/soothability define the second factor, “negative emotionality”. The third factor, “effortful control”, includes the dimensions of attention, inhibitory control, low intensity pleasure and perceptual sensitivity. In the US sample smiling and laughter loaded mainly on the third factor, and approach and attention loaded almost identically on all three factors. In the version of CBQ used in the present study, attention was split into attentional focusing and attentional shifting. In the studies in the US and China referred to below, the dimension of attention is identical with attentional focusing as used here. The questionnaire was translated by one of the authors (AMT), and ambiguous items were discussed with colleagues and resolved before use. SPSS for MS Windows Release 6.1.3 was used for all statistics.
RESULTS Background variables Among the children with Down syndrome, there were significant negative correlations between age and the following three temperamental dimensions: activity (r = −0.42, p = 0.002), falling reactivity/soothability (r = −0.36, p = 0.007) and high intensity pleasure (r = −0.36, p = 0.008). This means © 2002 The Scandinavian Psychological Associations.
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that the younger children were more active, calmed down quicker, and enjoyed more often high intensity pleasures than the older ones. Within the other two groups age did not vary significantly. The age differences between the three groups (Table 1) must be taken into account when discussing group differences in temperament. There were no gender differences in temperament among the children with Down syndrome or in the control group. In the group of premature children the following sex differences were found: anger (boys higher, t = 2.16, p = 0.03), attentional shifting (girls higher, t = 2.27, p = 0.03) and high intensity pleasure (boys higher, t = 2.16, p = 0.03). In the group of children with Down syndrome, SES as measured by parental education (National Bureau of Statistics, 1989) did not correlate significantly with any of the temperament dimensions. SES as measured by the parents’ profession (National Bureau of Statistics, 1984) correlated significantly only with activity (r = −0.30, p = 0.03) and low intensity pleasure (r = 0.33, p = 0.01). In the group of premature children parents with high SES had children with significantly more low intensity pleasure (r = −0.24, p = 0.02). Table 2 presents the internal consistency coefficient for the 16 CBQ scales for each of the three groups. The internal consistency varied between 0.43 and 0.87. Mean internal consistency in the Norwegian samples was 0.67, which is very similar to the Chinese sample (0.65), but lower than the value reported for the US sample (0.77). Among the children with Down syndrome 17 questions were negatively related to the dimension they belonged to. In the group of premature children this was true for five of the questions, and in the control group for seven of the questions. For comparative reasons each question was analyzed as if it belonged to the same dimension in each of the three groups. It is thereby possible to compare the data of the three current groups as well to compare the present data with data obtained from the Chinese and US samples.
Mean differences Table 3 presents the means and standard deviations of the three groups of participants. There were no differences in the total average between the groups. Children with Down syndrome scored significantly lower on the dimensions of attentional focusing, inhibitory control, and sadness than did the control group. This means that they were perceived to have less ability to sustain attention, to inhibit their impulses, and express sadness. Children with Down syndrome were also rated lower than the premature children on activity level and inhibitory control; that is, they were seen to have lower activity level and less ability to inhibit their impulses. Premature children were rated lower than the control group on attentional focusing, which implies that they appeared to have less ability to sustain attention. There were no significant differences between the groups on any of the following factors: “surgency”, “negative emotionality”, and “effortful
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Table 2. CBQ scale of internal consistency (n) in the present groups and in US and Chinese samples (Ahadi et al., 1993) Children with Down syndrome (n = 55)
Premature children (n = 97)
Normally developing children (n = 91)
US (Ahadi, et al., 1993) (n = 262)
China (Ahadi et al., 1993) (n = 468)
Activity Anger Approach Attentional focusing Attentional shifting Discomfort Falling reactivity/soothability Fear High intensity pleasure Impulsitivity Inhibitory control Low intensity pleasure Perceptual sensitivity Sadness Shyness Smiling and laughter
0.74 0.72 0.47 0.60 0.57 0.61 0.56 0.79 0.81 0.49 0.76 0.43 0.61 0.61 0.77 0.56
0.66 0.77 0.71 0.77 0.51 0.65 0.57 0.67 0.83 0.72 0.77 0.66 0.68 0.55 0.87 0.64
0.79 0.78 0.63 0.70 0.45 0.54 0.59 0.73 0.77 0.79 0.78 0.64 0.56 0.50 0.87 0.79
0.81 0.76 0.76 0.74 0.74 0.74 0.80 0.69 0.79 0.78 0.74 0.70 0.77 0.67 0.94 0.79
0.74 0.70 0.65 0.43 0.43 0.62 0.43 0.74 0.76 0.63 0.71 0.62 0.67 0.52 0.85 0.66
Mean internal consistency
0.63
0.77
0.65
(49) (45) (43) (48) (51) (40) (47) (16) (44) (32) (33) (43) (34) (35) (46) (39)
(80) (79) (86) (88) (93) (73) (89) (41) (76) (84) (65) (90) (59) (81) (86) (83)
0.69
(72) (68) (70) (69) (80) (54) (72) (51) (66) (62) (69) (67) (59) (70) (73) (64)
0.68
Notes: Cronbach’s alpha is used as measure of internal consistency. Attention is split into two dimensions in the Norwegian sample.
Table 3. CBQ means and standard deviations Children with Down syndrome (n = 55)
Premature children (n = 97)
Normally developing children (n = 91)
F-ratio
Activity Anger Approach Attentional focusing Attentional shifting Discomfort Falling reactivity/soothability Fear High intensity pleasure Impulsitivity Inhibitory control Low intensity pleasure Perceptual sensitivity Sadness Shyness Smiling and laughter
4.32 4.29 4.98 4.26 3.87 4.33 4.81 3.93 4.46 4.27 4.23 5.53 4.65 4.11 3.37 5.54
4.67 4.38 4.91 4.42 4.01 4.26 4.78 3.88 4.63 4.40 4.59 5.31 4.79 4.29 3.26 5.53
4.56 4.55 4.99 4.83 3.78 4.10 4.72 3.90 4.79 4.38 4.67 5.32 4.89 4.38 3.30 5.66
3.51* D < P 2.10 0.39 9.11*** D,P < N 1.74 1.83 0.55 0.05 2.70 0.55 5.62** D < P,N 2.75 1.83 3.17* D < N 0.22 1.23
Total
4.46 (0.24)
(0.87) (0.74) (0.56) (0.82) (0.87) (0.76) (0.60) (0.84) (0.91) (0.75) (0.86) (0.50) (0.75) (0.69) (1.04) (0.63)
(0.64) (0.79) (0.61) (0.93) (0.81) (0.76) (0.53) (0.83) (0.85) (0.67) (0.75) (0.53) (0.73) (0.63) (0.95) (0.49)
4.52 (0.23)
(0.87) (0.80) (0.64) (0.77) (0.80) (0.70) (0.59) (0.82) (0.82) (0.76) (0.80) (0.71) (0.72) (0.62) (0.97) (0.72)
4.56 (0.27)
2.73
Notes: Overall main effect of group differences tested with one-way ANOVA. The Bonferroni test was used to assess which groups were significantly (p < 0.05) different from each other. * Overall significant effect of group differences, p ≤ 0.05. ** Overall significant effect of group differences, p ≤ 0.01. *** Overall significant effect of group differences, p ≤ 0.001. D means children with Down syndrome, P means premature children and N means normally developing children.
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control”. There were no significant differences in any of the temperamental dimensions between premature children with birth weights below and above 1000 g.
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Table 5. Factor loadings of CBQ scales for premature children (n = 96) Factor1: Surgency
Factor 2: Negative emotionality
Factor 3: Effortful control
0.73 0.49 0.48 −0.29 −0.32 −0.07
0.04 0.54 0.61 −0.00 −0.14 0.65
−0.30 −0.36 0.05 0.70 −0.03 0.19
−0.14 −0.10 0.76 0.83 −0.47 −0.19 0.09 0.13 −0.37 0.35
−0.41 0.65 −0.19 −0.08 −0.03 0.09 0.38 0.76 0.49 0.02
0.56 0.01 −0.13 −0.32 0.77 0.64 0.48 0.01 −0.04 0.72
Temperament structure The 16 CBQ scale scores were factored for the three groups. A principal component analysis was employed, iterated to communalities, and with the extracted factors obliquely rotated using the direct oblimin algorithm. Based on an earlier factor analysis (Ahadi et al., 1993), three factors were extracted. Tables 4, 5 and 6 present the rotated structure matrix (correlations between variables and factors) for the three groups. All three groups yielded the three expected factors. The following dimensions had main loading differences between the groups, which compares well with the results obtained on the US and Chinese samples (Ahadi, et al., 1993): Approach loaded mainly on “negative emotionality” among the children with Down syndrome as well as in the group of premature children. This was similar to what was found in the US sample. As in the Chinese sample, approach loaded highest on “surgency” in the control group. Attentional shifting loaded negatively on “negative emotionality” among the children with Down syndrome and in the control group, whereas this dimension was negatively loaded on “surgency” among the premature children. In the
Activity Anger Approach Attentional focusing Attentional shifting Discomfort Falling reactivity/ soothability Fear High intensity pleasure Impulsitivity Inhibitory control Low intensity pleasure Perceptual sensitivity Sadness Shyness Smiling and laughter
Notes: Loadings greater than or equal to 0.40 are presented in bold. On the factor “surgency” the sign was reversed compared with what was expected, but is presented in the same way as in the other two samples. The factors were sorted in the same order as in studies in the US and China (Ahadi et al., 1993). The three factors explained 52.8% of the variance between the 16 dimensions.
Table 4. Factor loadings of CBQ scales for children with Down syndrome (n = 55)
Activity Anger Approach Attentional focusing Attentional shifting Discomfort Falling reactivity/ soothability Fear High intensity pleasure Impulsitivity Inhibitory control Low intensity pleasure Perceptual sensitivity Sadness Shyness Smiling and laughter
Factor1: Surgency*
Factor 2: Negative emotionality
Factor 3: Effortful control
0.77 −0.05 0.30 0.19 −0.00 −0.34
−0.04 0.73 0.58 −0.05 −0.38 0.72
−0.32 −0.07 −0.04 0.58 0.35 0.16
0.08 −0.32 0.68 0.81 −0.09 −0.13 −0.34 −0.03 −0.56 0.59
−0.48 0.67 −0.44 −0.05 0.05 0.03 0.04 0.75 0.45 0.13
0.50 −0.09 0.17 −0.20 0.79 0.77 0.55 0.15 0.01 0.35
Notes: Loadings greater than or equal to 0.40 are presented in bold. * In the factor analysis for the children with Down syndrome, “negative emotionality” was the first factor, “effortful control” the second, and “surgency” the third factor. The three factors explained 52.9% of the variance between the 16 dimensions. © 2002 The Scandinavian Psychological Associations.
Table 6. Factor loadings of CBQ scales for normally developing children (n = 88)
Activity Anger Approach Attentional focusing Attentional shifting Discomfort Falling reactivity/ soothability Fear High intensity pleasure Impulsitivity Inhibitory control Low intensity pleasure Perceptual sensitivity Sadness Shyness Smiling and laughter
Surgency*
Negative emotionality
Effortful control
0.86 0.28 0.66 −0.38 −0.24 −0.12
0.13 0.72 0.46 −0.13 −0.47 0.57
−0.16 −0.22 0.12 0.69 0.31 0.29
0.03 −0.13 0.76 0.90 − 0.48 −0.06 0.12 0.14 − 0.61 0.47
− 0.47 0.77 0.06 0.01 −0.29 −0.01 0.22 0.76 0.43 −0.05
0.50 0.05 −0.07 −0.16 0.72 0.78 0.68 −0.05 −0.14 0.66
Notes: Loadings greater than or equal to 0.40 are presented in bold. * “Surgency” was the first factor, “effortful control” the second, and “negative emotionality” the third factor. The three factors explained 60.5% of the variance between the 16 dimensions.
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US and Chinese sample this dimension was included in the dimension of attention. In the US sample attention loaded on “effortful control”, while in the Chinese sample it belonged to all three factors. The dimension of attentional shifting had low internal consistency in all samples except the one from the US, and one must therefore be careful when interpreting the results. Falling reactivity/soothability loaded positive on “effortful control” for all three Norwegian groups. In the US and Chinese samples this dimension loaded mainly on “negative emotionality”. Smiling and laughter loaded mainly positive on “surgency” among the children with Down syndrome (similar to the Chinese sample). For the premature children and the control group this dimension loaded highest on “effortful control” and to some extent on “surgency”, as was also the case in the US sample. Tables 7, 8, and 9 present the congruence coefficients between the different factor structures. The magnitude of the congruence coefficient for the first factor, “surgency”, between the children with Down syndrome and the four other samples was between 0.78 and 0.84. These values are statistically significant (p ≤ 0.05; see Catell, 1978), but suggest some discrepancy between the factor structures. On the first factor, the congruence coefficient was high between all the other groups. All national groups had high congruence coefficient on the second factor, “negative emotionality”. On the third factor, “effortful control”, there was high congruence between the Norwegian groups. The significant but lower congruence between the Norwegian and the US/ Chinese samples (0.79–0.91) suggests some discrepancy between the three countries. In general there were low and no significant correlations between the three factors. In the group of children with Down
Table 7. Congruence coefficient (Catell, 1978) for loadings for factor 1, “surgency”, between the three Norwegian samples and samples from China and the US (Ahadi et al., 1993) Premature children
Children with Down syndrome Premature children Normally developing children Chinese sample
−0.78
Normally developing children
Chinese sample
US sample
0.83
0.83
0.84
−0.97
−0.88
−0.96
0.92
0.96
Children with Down syndrome Premature children Normally developing children Chinese sample
Premature children
Normally developing children
Chinese sample
US sample
0.95
0.91
0.95
0.94
0.93
0.93
0.93
0.94
0.96
0.97
Notes: Factor loadings for attentional from the US and Chinese samples were used as estimates for their separate loadings on attentional focusing and attentional shifting. All congruence coefficients are significant (p ≤ 0.05). Table 9. Congruence coefficient (Catell, 1978) for loadings for factor 3, “effortful control”, between the three Norwegian samples and samples from China and the US (Ahadi et al., 1993)
Children with Down syndrome Premature children Normally developing children Chinese sample
Premature children
Normally developing children
Chinese sample
US sample
0.90
0.94
0.91
0.82
0.95
0.81
0.79
0.89
0.87
0.81
Notes: Factor loadings for attentional from the US and Chinese samples were used as estimates for their separate loadings on attentional focusing and attentional shifting. All congruence coefficients are significant (p ≤ 0.05).
syndrome “negative emotionality” and “surgency” were negatively related (r = −0.11). In the group of premature children “effortful control” and “surgency” were positively related (r = 0.12). No other correlations were above 0.10 within any of the three groups.
DISCUSSION 0.87
Notes: Factor loadings for attentional from the US and Chinese samples were used as estimates for their separate loadings on attentional focusing and attentional shifting. All congruence coefficients are significant ( p ≤ 0.05). © 2002 The Scandinavian Psychological Associations.
Table 8. Congruence coefficient (Catell, 1978) for loadings for factor 2, “negative emotionality”, between the three Norwegian samples and samples from China and the US (Ahadi et al., 1993)
The present study provides information about cross-sectional differences in temperament between children with Down syndrome, premature children, and a control group of normally developing participants. Differences in levels on temperament dimensions are reported as well as differences in temperament structure.
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The reliability and validity of CBQ have been reported elsewhere (Ahadi et al., 1993), but neither have been previously assessed on a Norwegian group, nor in children with Down syndrome or in premature children. The low internal reliability of some of the dimensions in the present groups (see Table 2) probably contributes to an underestimation of group differences. Due to the lack of a Norwegian standardization it was essential to include a control group. In the current study two groups with known etiology were compared with a control group comprising normally developing children. Thus, it was possible to evaluate differences in mean values and temperament structures. Since temperament dimensions are known to change with age (Eisenberg, 1998; Ratekin, 1996), it was important to take into account the age differences between the three groups. The three significant correlations found in this study between age and temperament among the children with Down syndrome are in line with general ideas about changes of temperament with age, and these relationships probably also apply to the two other groups of children. Gender differences in temperament may vary from culture to culture (Ahadi et al., 1993). The present study reports only small gender differences, which did not influence the evaluation of group differences. The present study demonstrated that parents with higher SES found their children to have more low intensity pleasure. This was the case among the children with Down syndrome as well as in the group of premature children. Due to the low internal consistency of this dimension within the group of children with Down syndrome, these results should be interpreted with caution. The parents of the children with Down syndrome had a higher mean education than the parents of both the premature children and the control group, and their children were reported to have more (but not statistically significant) low intensity pleasure than the two other groups of children. This suggests that parents with higher SES are likely to report their children to have a higher level of “effortful control”. This interpretation was supported by the findings that higher-SES parents of children with Down syndrome reported their children to have a lower activity level. If this interpretation is correct, it supports the general idea that parental SES may influence children’s temperament in the direction of more quiet play. It could also indicate that parents with higher SES are more attuned to small nuances in their children’s emotional life.
Children with Down syndrome Children with Down syndrome were found to have less focused attention than the participants in the control group and less inhibitory control than the premature children and the control group. This supports earlier findings of lower sustained attention among children with Down syndrome (Cielinski, Vaughn, Seifer & Contreras, 1995; Legerstee & Weintraub, 1997). Other studies have found that youngsters © 2002 The Scandinavian Psychological Associations.
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with Down syndrome are less persistent than other children (Bridges & Cicchetti, 1982; Green et al., 1989; Gunn & Berry, 1985a; Gunn & Berry, 1985b; Gunn & Cuskelly, 1991; Marcovitch et al., 1986; Pueschel & Myers, 1994; Ratekin, 1996). Children with Down syndrome are also reported to be more distractible (Gunn & Berry, 1985a; Gunn & Cuskelly, 1991; Ratekin, 1996). Pueschel, Bernier and Pezzullo (1991) found them to be less able to concentrate and more impulsive. Others have reported no differences in persistence (Vaughn, Contreras & Seifer, 1994) or in distractibility (Bridges & Cicchetti, 1982; Gunn & Berry, 1985b; Pueschel & Myers, 1994; Vaughn et al., 1994). Green et al. (1989) found children with Down syndrome to be less distractible, but their study included only 13 children. Landry & Chapieski (1989) found that it was harder to get infants with Down syndrome to focus their attention than it was with premature infants. The present study of children 4–11 years of age did not yield the same results. Less attentional focusing and less inhibitory control can only partly be explained by the fact that the children with Down syndrome had a lower cognitive age. In the current study there were no significant associations between chronological age and attentional focusing (r = −0.04) or inhibitory control (r = 0.18). The lack of consistency among the different studies, and the lack of substantial differences compared with controls matched on mental age, precludes any definite conclusions. The children with Down syndrome had significant lower activity level than the premature children, but activity level was not significantly lower than in the control group. This result corresponds to Gunn and Cuskelly’s (1991) finding of a lower activity level in children with Down syndrome between 8 and 14 years of age. Most studies have found no difference in activity level between infants/children with Down syndrome and control groups (Bridges & Cicchetti, 1982; Green et al., Bennets, 1989; Gunn & Berry, 1985b; Pueschel & Myers, 1994; Rothbart & Hanson, 1983; Vaughn et al., 1994). Pueschel et al. (1991) reported that children with Down syndrome had a more hyperactive profile than control children, but this was mainly related to concentration and impulsiveness. The present study confirms Gunn & Cuskelly’s (1991) finding that older children with Down syndrome are less active than younger ones. The fact that the participants with Down syndrome were older than the premature children probably partly explains their lower activity level. The higher educational level of the parents of children with Down syndrome could also have contributed to this difference. The children with Down syndrome also demonstrated significantly less sadness than the control group. When this finding is compared with the observations of less anger and higher discomfort, one gets the following impression: Children with Down syndrome complain less about, and accept more of, the normal and trivial difficulties of life. At the same time they are more often ill and have more real discomforts to complain about. In this context it is also of interest to note
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that the difference between low and high intensity pleasure was significantly higher for the children with Down syndrome than for the control group (F = 4.35, p = 0.014). Thus the children with Down syndrome had a tendency to prefer low intensity pleasure (i.e., calm/quiet play) instead of high intensity pleasure (i.e., rough play). Due to the negative correlation between age and high intensity pleasure, this finding could also be partly explained by the higher mean age of the group of children with Down syndrome. The current study did not find any group difference with respect to smiling and laughter, and thus does not support the earlier stereotype of a good-tempered child with Down syndrome (Gibbs & Thorpe, 1983; Gibson, 1978,). Some studies have reported that children with Down syndrome have a more positive mood (Gunn & Berry, 1985a; Gunn & Berry, 1985b; Gunn & Cuskelly, 1991; Kasari, Mundy, Yirmiya & Sigman, 1990; Ratekin, 1996). However, Rothbart and Hanson (1983) found that infants with this syndrome tend to score lower on smiling and laughter than do normal controls. There has also been reported less intensive distress among infants with Down syndrome (Thompson, Cicchetti, Lamb & Malkin, 1985). Other studies have not reported any differences in mood (Beeghly, Perry & Cicchetti, 1989; Bridges & Cicchetti, 1982; Green et al., 1989; Pueschel & Myers, 1994; Vaughn et al., 1994). Most studies have not separated the different aspects of mood, and this could be a reason for the lack of conclusive findings. Another reason could be that the emotionality of children with Down syndrome might change with age. As an example, Ratekin (1996) reported that infants with Down syndrome were more positive in mood than were older children. So far, though, there is not enough evidence to agree with Gibson’s (1978) caricature: “the placid, sensorially insufficient infant becomes an emotionally intact and outgoing child who turns subsequently into a sullen adolescent” (p. 148).
Premature children The only significant difference in mean temperament between the premature children and the control group was that the former had less attentional focusing. This finding is supported by earlier studies reporting that premature children are less persistent or attentive (Field, Hallock, Ting et al., 1978; Gennaro, Medoff-Cooper & Lotas, 1992; Minde et al., 1989; Schraeder & Medoff Cooper, 1983), and more impulsive (Wiener et al., 1965). Others have found no difference in persistence or duration of orienting (Plunkett et al., 1989; Prior et al., 1989; Roth, Eisenberg & Sell, 1984; Watt, 1987). In the present study the difference between the premature group and the control group was only about half of a standard deviation. We found no difference in the temperamental dimensions often associated with attentional focusing, such as inhibitory control, soothability or low intensity pleasure. The discrepancy between the studies may be explained by a small and specific difference in the attention span for this group. © 2002 The Scandinavian Psychological Associations.
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The present results do not support earlier findings of a lower activity level for premature children (Bakeman & Brown, 1980; Crnic, Ragozin, Greenberg, Robinson & Basham, 1983; Prior et al., 1989). This is probably due to the fact that most studies reporting differences in activity level have studied infants below 1 year of age. Studies reporting a higher activity level (Minde et al., 1989; Plunkett et al., 1989) among premature children have observed children between 1 and 4 years of age. This could imply a change from a lower activity level in infancy toward a higher level in early childhood. At 5 years of age there seems to be no difference. Wiener et al.’s (1965) study, reporting no increased level of hyperactivity in premature children, 6–7 years aged, supports this conclusion. To our knowledge Wiener et al. have published the largest study of temperament among prematures, including almost 400 participants. Earlier studies have found premature infants to be less approaching, less sociable (Garcia Coll et al., 1992), and less involved with and responsive to their mother (Barnard, Bee & Hammond, 1984; Crnic et al., 1983). Some studies have reported that premature infants gaze less at their mothers (Field, 1977; Malatesta et al., 1986), whereas Van Beek et al. (1994) found them to look more at their mothers. All these observations were done on infants below 7 months of age. Several investigators have not found premature children to be less approaching, less sociable or shyer. These comprise studies of children above 1 year of age (Grunau, Whitfield & Petrie, 1994; Prior et al., 1989; Schraeder & Medoff Cooper, 1983) and those between 6 months and 1 year of age (Field, Hallock, Dempsey et al., 1978; Roth et al., 1984; Watt, 1987). The current study also failed to find that premature children are less approaching or shyer. It is evident that there may be differences in premature infants’ sociability and approach during the first months of their life, but such differences probably disappear during the end of the first year of life. This could be due to a lower activity level during infancy, and to more fussy signals and unpredictable rhythms during the first months of life (Field, Hallock, Ting et al., 1978; Gennaro et al., 1992; Gennaro, Tulman & Fawcett, 1990; Schraeder & Medoff Cooper, 1983). There are also studies that report no differences in fussiness or rhythmicity (Field, Hallock, Dempsey et al., 1978; Halpern & McLean, 1997; McGrath, Boukydis & Lester, 1993; Prior et al., 1989; Roth et al., 1984; Watt, 1987). Having an unpredictable infant might influence the mother’s stress, feeling of self-efficacy, and competence (Halpern & McLean, 1997; McGrath et al., 1993). Naturally, in studies of temperament it may be hard to separate out the mother’s competence, the infant’s sociability, and its lack of clear signals and stable rhythms. This may explain the contradictory findings of sociability. Some studies have found that premature infants smile less (Crnic et al., 1983), and show more negative affect (Malatesta et al., 1986) than normal controls. Premature children have also been found to have more temper tantrums at 3–4 years
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of age (Minde et al., 1989; Prior et al., 1989). Other researchers have reported no differences in neither positive nor negative mood (Crnic et al., 1983; Field, Hallock, Dempsey et al., 1978; Garcia Coll et al., 1992; Grunau et al., 1994; Plunkett et al., 1989; Prior et al., 1989; Roth et al., 1984; Schraeder & Medoff Cooper, 1983; Van Beek et al., 1994; Watt, 1987; Wiener et al., 1965). These studies, which cover infancy as well as early childhood, support our results of no observed differences between premature and normally developing children with respect to the temperament dimensions tapping mood (anger, soothability, fear, high intensity pleasure, low intensity pleasure, sadness or smiling and laughter). If there are any group differences in mood and temper, they seem to be small and without much consequence.
Structural differences The congruence coefficients between the children with Down syndrome and the other two groups in Norway on the factor called “surgency/positive affect” were 0.78 and 0.83, respectively. Even if these coefficients are significant they may reflect a combination of several loading differences. Anger, approach and attentional shifting loaded less, and inhibitory control loaded much less among the children with Down syndrome than in the other two groups. Discomfort, fear, perceptual sensitivity and smiling and laughter loaded higher. This means that for children with Down syndrome the “surgency” factor may be more influenced by emotional processes and less influenced by effortful control, as compared with prematures and normally developing children. The factor structure of “surgency” was almost identical for premature children and the control group, with a congruence coefficient of 0.97. When comparing the current control group’s structure with that of the Chinese and US samples of Ahadi et al. (1993), we found congruence coefficients of 0.92 and 0.96, respectively. This indicates less cultural differences than the one observed between the US and Chinese samples, where the congruence coefficient was 0.87. Looking at the individual dimension loadings, one sees that in general the Norwegian groups were rather similar to the Chinese and US samples. There was a high degree of similarity in defining the factor of “negative emotionality”. This conclusion applies to the three groups in the present study, and also seems to be valid when we compared our results with those obtained with the US and Chinese samples (congruence coefficients between 0.91 and 0.97). The only noticeable difference was that high intensity pleasure loaded negatively on this factor among the children with Down syndrome, but not in the control group, where it loaded exclusively on “surgency/ positive affect”. This means that for children with Down syndrome the factor of “negative emotionality” is partly defined by a lack of rough play. This is supported by the correlation of −0.11 between the factors of “negative emotionality” and “surgency/positive affect” among the children © 2002 The Scandinavian Psychological Associations.
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with Down syndrome. No such correlation was found in the other groups. On the factor of “effortful control” there was a high degree of similarity between the three Norwegian groups, with congruence coefficients between 0.90 and 0.95. The only major exception was smiling and laughter, which loaded much less for the children with Down syndrome than for the other two groups. Among the children with Down syndrome the expression of happiness was more associated with high activity level and impulsivity than with attention, calmness and patience. The present study supports an earlier finding of cultural differences in the definition of “effortful control” (Ahadi et al., 1993). We report congruence coefficients between the current control group and the US and Chinese samples of 0.89 and 0.87, respectively. Falling reactivity/soothability loaded on the factor of “effortful control” instead of on “negative emotionality” as in the other two countries. As in the US sample smiling and laughter loaded on “effortful control”, whereas in the Chinese sample smiling loaded on “surgency/positive affect”. Within the Norwegian culture “effortful control” fits the definition of being able to express joy and quickly to calm down after an exciting event.
Conclusion We found that children with Down syndrome had less attentional focusing, less inhibitory control, and demonstrated less sadness than other children did. Specifying the dimensions of what is included in the generally described temperament of “mood” yielded valuable information about what might be special about children with Down syndrome. Attentional focusing seemed to be the only temperamental dimension that was significantly different for the premature children. The present study suggests that there are very few substantial temperamental differences for this group of children. Moreover, this study reports some differences in temperament structures. Most importantly, children with Down syndrome were endowed with a temperament factor called “surgency/positive affect”. This factor is more of an emotional nature and less influenced by the dimensions within the factor “effortful control”, compared with premature youngsters and normally developing children. The general picture is that the temperamental differences found in this study, as well as in other investigations, are rather small, and that the within-group variation is high. Stereotyped perceptions of the temperament of children with Down syndrome or among premature children are therefore not necessarily accurate or helpful on an individual basis. This work was supported by the Høyesterettsadvokat Eckbos Foundation, the Åsa Gruda Skards Foundation, the Sigurd K. Thoresen Foundation, and the Professor Dr. Mourly Vold and Sister’s Foundation. We extend thanks to all the families who participated in the study.
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