General Findings
Before discussing the main results of the present study, a number of general findings will be addressed. First, independent t-tests revealed that girls displayed higher KFQ total and “fear of the unknown” scores than boys (Ms being 57.45, SD = 10.94 and 9.63, SD = 2.94 versus 50.83, SD = 12.15 and 8.39, SD = 2.94, respectively; both t(222)’s ≥ 3.15, p < .01). No other gender differences were observed for indexes of cognitive development, behavioral inhibition, and anxiety, and therefore it was decided not to include gender as a covariate in further analyses.
Second, reliability analyses were carried out on various PAS-R, BIQ, and KFQ scales, and indexes of cognitive development (i.e., conservation tasks, TOM-test). Table 1 shows the internal consistency coefficients (Cronbach’s alphas) and item-total correlations for these measures. The internal consistency of most scales was good (with Cronbach’s alphas between .75 and .95) and this was generally also true for the item-total correlations (r’s between .12 and .84).
Table 1 Mean scores (standard deviations), Cronbach’s alphas, and item-total correlations for instruments measuring children’s anxiety symptoms, behavioral inhibition, fears, and cognitive development
Third, significant and substantial correlations were observed between the BIQ and PAS-R scales: a correlation of .70 (p < .01) was found between the total scores of both questionnaires, whereas correlations among various (sub) scales varied between .38 (BIQ social novelty and PAS-R separation anxiety) and .74 (BIQ non-social novelty and PAS-R total scale).
Fourth and finally, a positive association was found between performance on the TOM-test and the score on the conservation tasks (r = .55, p < .001). Age also correlated positively with scores on the TOM-test (r = .69, p < .001) and the conservation tasks (r = .62, p < .001). Additional analyses revealed that TOM-test scores of 4- and 5-year-old children (M = 26.13, SD = 6.71) were significantly lower than those of 6- and 7- (M = 34.18, SD = 2.85; p < .001) and 8- and 9-year-old children [M = 35.48, SD = 2.46; p < .001; F(2,221) = 88.87, p < .001]. On the conservation tasks, 4- and 5-year-old children (M = 0.78, SD = 1.45) scored significantly lower than 6- and 7-year-old children (M = 2.97, SD = 1.98; p < .001), who in their turn scored significantly lower than 8- and 9-year-old children [M = 3.80, SD = 1.52; p < .05; F(2,221) = 65.58, p < .001].
Age Differences in Anxiety Phenomena
Table 2 shows the mean scores and standard deviations for the total scale and relevant subscales of the PAS-R, BIQ, and KFQ for the three age groups separately. Analyses of variance (ANOVAs) yielded a significant effect of age for the PAS-R generalized anxiety scale [F(2,223) = 5.73, p < .01]. Four- and 5-year-old children (M = 13.40, SD = 4.88) displayed lower scores on this scale than children in the two older age groups (Ms being 15.75, SD = 5.29 and 15.90, SD = 5.84, respectively; both p’s < .05). KFQ scores also differed among the age groups, and this was true for the KFQ total scale [F(2,221) = 5.94, p < .01] as well as for the “fear of the unknown” scale [F(2,221) = 22.86, p < .001]. Post-hoc comparisons revealed that 4- and 5-year-olds (M = 57.65, SD = 12.72) exhibited significantly higher total fear scores than the 6- and 7- (M = 52.44, SD = 11.73; p < .05) and 8- and 9-year-olds (M = 51.81, SD = 9.65; p < .05). A similar pattern was observed for the scores on the KFQ “fear of unknown” subscale: again children of the youngest age group (M = 10.53, SD = 3.08) scored significantly higher than children of the older two age groups (Ms being 8.30, SD = 2.75 and 7.69, SD = 2.00; both p’s < .001).
Table 2 Mean scores (and standard deviations) on PAS-R, BIQ, and KFQ for the three age groups
The most frequently endorsed items of the PAS-R in the 4- and 5-year-olds were mainly related to social anxiety and specific fears (e.g., unfamiliar people, dogs, and the dark), whereas the most prevalent items in 6- and 7- and 8- and 9-year-olds predominantly consisted of items from the social anxiety and generalized anxiety scales (e.g., new people, looking stupid, doing the right thing, and new unusual situations). Inspection of the most frequently endorsed BIQ items revealed that there were few systematic differences in the type of inhibited behaviors across the three age groups. Performing in front of others, approaching unfamiliar children, and being the center of attention were most common among children of all ages. Inspection of the most prevalent KFQ items revealed that more infantile fears (e.g., witches, crocodiles, and lions) ranked somewhat higher in the hierarchy of younger children, whereas more abstract fears (e.g., war and your parents getting divorced) listed higher in the ranking of older children.
Relation Between Cognitive Development and Anxiety Phenomena
To study the effects of cognitive development on anxiety phenomena scores, correlations were computed between TOM-test and conservation tasks, on the one hand, and PAS-R, BIQ, and KFQ scores, on the other hand. Further, a series of linear regression analyses was carried out to examine unique contributions of cognitive development indexes (besides age) to various anxiety phenomena. In these analyses, scores on cognitive measures and age were entered as the predictors, whereas scores on the PAS-R, BIQ and KFQ total scales and subscales were the dependent variables.
The correlational analysis revealed that only the BIQ and the KFQ total scales were linked to the cognitive measures. That is, small but significant negative correlations were found between the BIQ total score and the TOM-test (r = −.15, p < .05). Further, the KFQ total score correlated negatively with scores on the TOM-test and the conservation tasks (r’s being −.19 and −.20, p’s < .01).
The results of the regression analyses revealed unique and significant contributions of TOM to various BIQ scales (Table 3). More precisely, TOM was a significant and independent predictor of total BIQ, BIQ social novelty, and BIQ non-social novelty scores. All standardized betas were negative, indicating that higher levels of TOM were associated with lower behavioral inhibition scores. Age emerged as an independent and significant predictor of the PAS-R total score, separation anxiety and generalized anxiety. In all cases, standardized betas were positive, indicating that a higher age was associated with higher levels of anxiety symptoms. Additionally, age was also a significant predictor of KFQ “fear of the unknown”: here the negative beta signified that higher age was related to lower levels of these infantile fears. Finally, conservation tasks also emerged as an independent and significant predictor of PAS-R separation anxiety; the standardized beta was negative, indicating that higher scores on the conservation tasks were associated with lower levels of separation anxiety.
Table 3 Effect of cognitive development and age on fear, anxiety and behavioral inhibition
Admittedly, the percentages of explained variance accounted for by age and cognitive development were generally low (between 2 and 6%). Only in the case of KFQ “fear of the unknown”, variables accounted for a relatively large percentage of the explained variance (i.e., 19%).