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The relationship of novelty preferences during infancy to later intelligence and later recognition memory
INTELLIGENCE 8, 339-346 (1984)
The Relationship of Novelty Preferences During Infancy to Later Intelligence and Later Recognition Memory* JOSEPH F. F A G A N , I I I
Psychology Department Case Western Reserve University Cleveland, OH 44106
In the present study, a group of children originally tested for visual novelty preferences at 7 months and seen for estimates of intelligence at 3 years were revisited and tested for intellectual functioning and for visual recognition performance at 5 years. Prediction from performance at 7 months to intellectual functioning at 5 years was significant and remained at the same level as prediction from 7 months to 3 years (r = .42 at each point). In addition, it was shown that data on early novelty preferences could be combined with information on birth-order and parental education to achieve good prediction (R = .65) of five-year IQ scores. A further goal of the present study was to discover if infants' preferences for visual novelty, assumed to be an early measure of visual recognition memory would be more highly associated with later visual recognition performance or with later intellectual level. The results indicate that novelty preferences were more highly related to later intelligence quotients than to later recognition performance and such a pattern of relationships did not appear to be artifactual.
One purpose o f the present longitudinal study was to e x a m i n e the year-to-year magnitude o f validity coefficients based on preferences for visual novelty obtained at 7 months for the prediction o f later intelligence at 3 and at 5 years. The second goal was to d i s c o v e r if infants' preferences for visual novelty, assumed to be an early measure o f visual recognition m e m o r y , w o u l d be more highly associated with later visual recognition p e r f o r m a n c e or with later intellectual level. Infants have a tendency to d e v o t e m o r e visual fixation time to some stimuli than to others. In particular, infants pay more attention to novel than to previously seen targets (Fagan, 1970). Individual differences among infants in preference for visual novelty have been linked to later differences in intelligence. Five reports are available in which the relationship between infants' attention to visual novelty and later intelligence has been explored. These studies by Yarrow, Correspondence and requests for reprints should be addressed to the author at the address listed above. *The preparation of this paper was supported, in part, by Major Research Project Grant HD-11089 from the National Institute of Child Health and Human Development.
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Klein, Lomonaco and Morgan (1975), Fagan (1981), Fagan and McGrath ( 1981), Lewis and Brooks-Gunn ( 1981 ), and by Fagan and Singer (1983) include tests of the predictive validity of early novelty preferences for 12 samples of children. Each of the 12 samples have yielded significant associations between early novelty preferences and later intelligence. Specifically, preferences for visual novelty during infancy have yielded moderate predictive validity coefficients ranging from 0.33 to 0.66 across the 12 samples with a mean of 0.44. Notably, these associations between early novelty preferences and later IQ appear to be of equal magnitude for intelligence measured at various points from 2 through 7 years. In contrast, conventional tests of infant intelligence based on sensori-motor functioning (e.g., Bayley, 1969) yield associations with later IQ which eventually decline to zero over the same time period. The conclusion that predictive validity coefficients based on early novelty preferences remain high from one later age to another, however, has been drawn from data obtained on independent samples. Each sample was tested at one point during infancy and again at only one later age. A more straightforward test of the stability of predictive validity estimates based on infant novelty preferences would be obtained by repeating intelligence tests from one age to another for the same sample of children. In the present study, a group of children originally tested for novelty preferences at 7 months and for performance on the Peabody Picture Vocabulary Test (PPVT) of intelligence at 3 years (Fagan, 1981; Fagan & Singer, 1983) were revisited at 5 years and again given the PPVT to determine if prediction from performance at 7 months to 5 years would remain at the same level as prediction from 7 months to 3 years. The present study was also concerned with the question of the basis of intellectual continuity over age. The empirical demonstration of continuity between early novelty preferences and later intelligence raises the theoretical question of the basis for such continuity. Fagan and McGrath (1981) adopt the working hypothesis that continuity over age in cognitive functioning reflects continuity in the same processes from age to age (e.g., the infant with advanced perception and memory processes is the child with such advanced processes). If so, the task of deciding what provides continuity in intellectual functioning becomes one of identifying similar processes underlying early novelty preferences and performance on later intelligence tests. Similar processes underlying two performance domains may be specific or general. Novelty preferences, for example, are typically taken as a working definition of infant visual recognition memory (e.g., Caron & Caron, 1968; Fagan, 1970). Perhaps the link between early novelty preferences and later performance on intelligence tests is specifically due to recognition memory. In other words, recognition per se may be related to intelligence at any age. Hence, the association between early novelty preferences and later intelligence may be mediated by a commonality in recognition memory functioning from age to age. Perhaps early novelty preferences and later recognition memory involve more of
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the same processes than are common to early novelty preferences and later intelligence. If so, we would expect that the association between early novelty preferences and later tests of recognition memory would be greater than the association between early novelty preferences and later intelligence. An alternative hypothesis is that the association between early novelty preferences and later intelligence is more general than simply a common link via recognition memory. In other words, there may be a more general association between early novelty preferences and later intelligence which involves a variety of similar cognitive and, perhaps, motivational processes. If so, the relationship between early novelty preferences and later intelligence would be greater than the association between early novelty preferences and later recognition memory. To decide between these specific or general hypotheses regarding the basis of intellectual continuity, children in the present study, tested for novelty preferences at 7 months, were administered tests of visual recognition memory as well as a test of intelligence at 5 years. Such a design allowed us to determine whether infants' preferences for visual novelty would be more highly associated with later visual recognition performance or with later intellectual level. METHOD The sample included 36 children (18 males, 18 females: 29 whites, 7 blacks) bom at term, who resided in suburban, middle-class neighborhoods. Each child was tested for novelty preferences at 7 months of age (29 weeks) on three pairings of achromatic face photos. Infants were asked to discriminate pairs of white women one from the other (two such tests) and to differentiate between two white babies. Specifically, for each of the three sets of photos, an infant was allowed to study a photo until 20 s of fixation had accumulated. Following study, the previously exposed face was paired with a novel face for two, 5-second test periods, with left-right positions of novel and familiar targets reversed from one 5-second period to the next. At 3 years the children were given the Peabody Picture Vocabulary Test (Form L) and two tests of immediate recognition memory: one test for 27 abstract patterns and one test for 27 unfamiliar cartoon faces. Examples of the abstract patterns and cartoon faces employed for recognition testing are given in Fagan (1984). For each recognition test (abstract patterns and cartoon faces) material was divided into spans ranging from two through seven items. A child was allowed to view each item within the span for 5 s. Following the study, the child was shown each previously exposed item paired with a novel item and was asked to point to the familiar item. Testing continued until all spans (in ascending order) within each type of material (patterns and faces) had been attempted. The persons administering tests at five years were not aware of the child's performance either at 3 years or at 7 months. Testers at 3 years had not known how the child had performed as an infant. The 36 children in the present sample
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were part of a larger group of 68 children seen at 3 years (as reported in Fagan, 1981; Fagan & Singer, 1983). The 36 children were also members of a sample of 52 children (the 16 additional children had not been tested at 7 months or at 3 years) seen at 5 years who were given tests of intelligence and recognition memory (as reported in Fagan, 1984). RESULTS Each child received three types of scores: a novelty preference score obtained during infancy and defined as the median percent of total fixation paid to novel targets over three tests; intelligence test scores based on the PPVT administered at 3 and at 5 years; and three recognition memory scores at 5 years, one for abstract patterns, one for cartoon faces, and one for both recognition subtests combined. The mean novelty preference score obtained by the sample at 7 months was 59.6% (SD = 11.9) with a range from 41 to 89). An estimate of the internal consistency of the novelty preference score was based on the mean intercorrelations among the three novelty problems according to a formula provided by Jensen (1980, Formula 7.1, p. 261). The resulting reliability coefficient of .32, while low, was in the range obtained in previous studies of early novelty preferences (Fagan & McGrath, 1981; Fagan & Singer, 1983) and was expected on the basis of the small number of tests (three) on which the median novelty preference score was based. The mean PPVT-IQ at 3 years for the sample was in the average range at 97.6 (SD = 16.9), with scores ranging from 65 to 135. The mean PPVT-IQ attained at 5 years by the same children was 105.8 (SD = 15.6) with a range from 76 to 136. Although it is not of interest in the present study, the increase in IQ from 3 to 5 years was most likely due to the use of Form A of the PPVT at 3 years and Form L at 5 years. The alternate form reliabilities of the PPVT at 3 years and at 5 years, as given by the authors of the test, are 0.75 (Dunn, 1965) and 0.80 (Dunn & Dunn, 1981), respectively. In the present sample, test-retest reliability from 3 to 5 years for PPVT-IQ scores proved to be high at 0.73. The recognition tasks at 5 years were of moderate difficulty with a mean total score (across tests for abstract patterns and for faces) of 43.3, SD = 7.0, out of a maximum possible score of 54, with individual scores ranging from 25 to 54. Recognition for abstract patterns (M 21.4, SD = 3.8) proved to be equivalent to recognition for cartoon faces (M 22.8, SD = 3.6). Individual differences in memory for patterns were highly related to memory for faces at r = .76, a value which may be taken to indicate the alternate form's reliability of the overall recognition test. One purpose of the present study was to discover if associations between early visual novelty preferences and later intellectual functioning would remain at the same level from 3 years to 5 years. The correlation between 7-month novelty
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preference and 3-year PPVT scores yielded a coefficient of 0.42 (df 35, p < .01), a value similar to the value of 0.36 obtained from the entire sample of 68 children from whom the present 36 subjects were drawn (Fagan & Singer, 1983). The relationship between 7-month novelty scores and 5-year PPVT-IQ was identical to that found between 7 months and 3 years at 0.42 (df35, p < .01). Neither of these two correlation coefficients of 0.42 exceeded the maximum coefficient possible given the reliabilities of the tests involved. At 3 years a maximum correlation of 0.49 was possible (obtained by multiplying the square roots of the reliabilities of each test by one another, assuming reliabilities of 0.32 for novelty tests and 0.75 for 3-year PPVT scores) and at 5 years a maximum of 0.51 was possible (given reliabilities of 0.32 for novelty scores and 0.80 for 5-year PPVT scores). In short, the level Of prediction from novelty preferences obtained at 7 months remained as high to 5-year IQ scores as it had to 3-year IQ scores, within the same sample of children. A second goal of the present study was to determine if infants' preferences for visual novelty would be more highly related to intellectual level at 5 years or to visual recognition performance at 5 years. As noted above, early novelty preferences were significantly associated with PPVT-IQ scores at 5 years at a value of 0.42. The association between early novelty preferences and recognition memory performances (total scores) at 5 years, however, was not reliably greater than chance at r = .23. The appropriate statistical test for the difference between the obtained values of 0.42 and 0.23 was problematic since one value (0.42) was significantly greater than zero and one value (0.23) was not significantly greater than zero. The analysis was further complicated by the fact that each value was severely attentuated by the low reliability (0.32) of the infant novelty preference test. The solution involved two steps. The first was to correct each correlation for attenuation due to unreliability (assuming reliabilities of 0.32 for early novelty preference scores, 0.76 for recognition testing at 5 years, and 0.80 for PPVT scores at 5 years) which yielded values of 0.83 and 0.46 in place of 0.42 and 0.23, respectively. The second step was to compare this value of 0.83 to that of 0.46 which yielded a Z score of 4.02, indicating an highly significant difference (p < .001) between the two coefficients. In addition, it should be noted that the low correlation between novelty preferences and later recognition performance did not appear to be a statistical artifact. Statistically, a value as great as that between novelty preferences and IQ was possible for the relation between novelty preferences and later recognition. In other words, the maximum coefficient between novelty scores and recognition scores could have reached 0.49, given the reliabilities of each test. The low correlation between early novelty scores and later recognition could also have been due to the fact that novelty preferences were based on distinctions among faces while later recognition tests included discriminations among abstract patterns as well as among faces. Such a possibility was ruled out by the fact that prediction from early novelty preferences to later recognition for faces was just as poor (r = .21) as prediction from early
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novelty scores was to later recognition of abstract patterns (r = .20). In short, early novelty preferences appear to be more highly related to later intelligence quotients than to later recognition performance and such a pattern of relationships does not appear to be artifactual. A final set of analyses sought to uncover any relationships between the sex, birth order, or level of parental education of the children and their verbal intelligence at 5 years. Two significant relationships emerged from the analysis. PPVT-IQ at 5 years was predicted by birth order (r = - . 3 0 , df35, p < .05) and by level of parental education (r = .39, df35, p < .01). Children earlier in birth order were brighter than later borns and the higher the level of parental education, the higher the child's IQ score. Such relationships, of course, are not surprising. They take on additional value in the present study, however, because neither was significantly related either to each other (r = .25) or to another predictor of 5-year IQ, i.e., novelty preferences at 7 months (correlations of - . 0 2 and .20 between novelty scores and birth-order and between novelty scores and parental education, respectively). A multiple regression analysis yielded an R value of 0.65 when 7-month novelty scores, birth-order, and level of parental education were combined to predict 5-year IQ scores. The point of such an analysis is not to show that any of these predictors of IQ is superior to the other, but only that predictors representing independent sources of variance can be combined to yield a more accurate estimate of later intellectual level. DISCUSSION In the present study, a group of children originally tested for visual novelty preferences at 7 months and seen for estimates of intelligence at 3 years were revisited and tested for intellectual functioning at five years. Prediction from performance at 7 months to 5 years was significant and remained at the same level as prediction from 7 months to 3 years, r = .42 at each point. In addition, it was shown that data on early novelty preferences could be combined with information on birth-order and parental education to achieve good prediction (R = .65) of 5-year IQ scores. Thus, the present results add to the accumulating literature on the prediction of later IQ from early visual novelty preferences in two ways. First, the present results show that correlation coefficients based on early novelty preferences remain stable over age in a longitudinally-studied sample. Second, these results add to the evidence (Fagan & Singer, 1983) that such coefficients can be combined with other correlates of intelligence to arrive at more accurate predictions of later intelligence. The present study was also concerned with the question of the basis of the continuity between novelty preferences and later intelligence. Given that novelty preferences are typically taken as a working definition of infant visual recognition memory, a simple hypothesis was tested in the present study. The hypothesis was that the association between early novelty preferences and later intelligence
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is mediated byrecognition memory, i.e., that recognition, per se, is related to intelligence at any age. If so, the expectation was that the association between early novelty preferences and later tests of recognition memory would be greater than the association between early novelty preferences and later intelligence. In fact, in the present study, quite the opposite occured. The relationship between early novelty preferences and later intelligence (r = .42) was statistically significant and greater than the statistically nonsignificant association between early novelty preferences and later recognition memory (r = .23). Perhaps the difficulty with our original hypothesis lay in the assumption that recognition memory is associated with intelligence at any age. One might conjecture that early recognition memory (as indexed by novelty preferences) is, indeed, a valid measure of early intelligence (and, hence, related to later intelligence), but that later recognition memory has little to do with later intelligence, perhaps because recognition, with age, becomes a highly automatic process. Such a notion would lead us to expect a low or zero correlation between early novelty scores and later recognition performance, such as was found in the present study. At the same time, such a notion would also predict a low or zero correlation between later IQ scores and later recognition performance. In the present sample, however, recgonition scores (totals) were highly related to 5year PPVT-IQ at r = .66 (df 35, p < .005). In effect then, while it is the case that recognition memory functioning at later ages is related to intelligence, it is not the case that early novelty preferences predict later intelligence because novelty preferences are an early measure of recognition memory. The present results tell us that the association between early novelty preferences and later intelligence is more general than simply a common link via recognition memory. But the question as to which processes constitute the association between early novelty preferences and later intelligence still remains. The answer to such a question requres the breakdown of early novelty preference tests and later intelligence tests into components and an analysis of the relations of the components in each task one to another. For example, consider some of the processes set into motion when a child is required to point to the correct picture when asked to identify the word " b u s " on the Peabody Picture Vocabulary Test. The child must note particular attributes (e.g., size, shape, function) common to the subset of vehicles we know as buses. He must also note features distinguishing buses from other vehicles. In addition, the detection of invariant features forming a pattern is necessary so that the object (bus) is identified as such despite changes in perspective, i.e., front, back, side, etc., and so that a picture or a line drawing of a bus is treated as similar to an actual bus. Finally, the word " b u s " must evoke the mental representation or prototype formed by past abstraction of the features common to buses. While the child answering questions on the PPVT must invoke such processes, it is also the case that the infant, in responding to visual novelty, may also reveal the working of those same processes. Specifically, studies of visual responsiveness to novelty have shown that the infant sepa-
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rates attributes, notes invariants in f o r m o v e r transformations in perspective, sees similarities across different representations, and can f o r m prototypes (see r e v i e w by Fagan, in press). In short, it is possible that s o m e o f the specific c o m p o n e n t s i n v o l v e d in solving p r o b l e m s on intelligence tests m a y also be studied by varying the conditions under which an infant is asked to demonstrate a preference for visual novelty. The study o f the relations o f such early and later processing to each other lies ahead.
REFERENCES Bayley, N. (1969). The Bayley Scales of Infant Development, Psychological Corporation, New York. Caron, R. F., & Caron, A. J. (1968). The effects of repeated exposure and stimulus complexity on visual fixation in infants. Psychonomic Science, 10, 207-208. Dunn, L. M. (1965). Peabody Picture Vocabulary Test. Circle Pines, MN: American Guidance Service. Dunn, L. M., & Dunn, L. M. (1981). Peabody Picture Vocabulary Test: Manual for Forms L and M. Circle Pines, MI: American Guidance Service. Fagan, J. F. (1970). Memory in the infant. Journal of Experimental Child Psychology, 9, 217-226. Fagan, J. F. (1984, April). Infant memory and the prediction of intelligence. Paper presented at Society for Research in Child Development Meeting, Boston, MA. Fagan, J. F. (1984). Recognition memory and intelligence. Intelligence, 8, 31-36. Fagan, J. F. (in press). A new look at infant intelligence. In D. K. Detterman (Ed.), Current topics in human intelligence: Research Methodology, (Vol. 1). Norwood, NJ: Ablex. Fagan, J. F., & McGrath, S. K. (1981). Infant recognition memory and later intelligence. Intelligence, 5, 121-130. Fagan, J. F., & Singer, L. T. (1983). Infant recognition memory as a measure of intelligence. In L. P. Lipsitt (Ed.), Advances in Infancy Research, (Vol. 2). Norwood, NJ: Ablex. Jensen, A. R. (1980). Bias in Mental Testing. New York: Free Press. Lewis, M., & Brooks-Gunn, J. (1981). Visual attention at three months as a predictor of cognitive functioning at two years of age. Intelligence, 5, 131-140. Yarrow, L. J., Klein, R. P., Lomonaco, S., & Morgan, G. A. (1975). Cognitive and motivational development in early childhood. "In B.X. Friedlander, G. M. Sterritt, & G. E. Kirk (Eds.), Exceptional infant, (Vol. 3). New York: Brunner/Mazel.
The Relationship of Novelty Preferences During Infancy to Later Intelligence and Later Recognition Memory* JOSEPH F. F A G A N , I I I
Psychology Department Case Western Reserve University Cleveland, OH 44106
In the present study, a group of children originally tested for visual novelty preferences at 7 months and seen for estimates of intelligence at 3 years were revisited and tested for intellectual functioning and for visual recognition performance at 5 years. Prediction from performance at 7 months to intellectual functioning at 5 years was significant and remained at the same level as prediction from 7 months to 3 years (r = .42 at each point). In addition, it was shown that data on early novelty preferences could be combined with information on birth-order and parental education to achieve good prediction (R = .65) of five-year IQ scores. A further goal of the present study was to discover if infants' preferences for visual novelty, assumed to be an early measure of visual recognition memory would be more highly associated with later visual recognition performance or with later intellectual level. The results indicate that novelty preferences were more highly related to later intelligence quotients than to later recognition performance and such a pattern of relationships did not appear to be artifactual.
One purpose o f the present longitudinal study was to e x a m i n e the year-to-year magnitude o f validity coefficients based on preferences for visual novelty obtained at 7 months for the prediction o f later intelligence at 3 and at 5 years. The second goal was to d i s c o v e r if infants' preferences for visual novelty, assumed to be an early measure o f visual recognition m e m o r y , w o u l d be more highly associated with later visual recognition p e r f o r m a n c e or with later intellectual level. Infants have a tendency to d e v o t e m o r e visual fixation time to some stimuli than to others. In particular, infants pay more attention to novel than to previously seen targets (Fagan, 1970). Individual differences among infants in preference for visual novelty have been linked to later differences in intelligence. Five reports are available in which the relationship between infants' attention to visual novelty and later intelligence has been explored. These studies by Yarrow, Correspondence and requests for reprints should be addressed to the author at the address listed above. *The preparation of this paper was supported, in part, by Major Research Project Grant HD-11089 from the National Institute of Child Health and Human Development.
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Klein, Lomonaco and Morgan (1975), Fagan (1981), Fagan and McGrath ( 1981), Lewis and Brooks-Gunn ( 1981 ), and by Fagan and Singer (1983) include tests of the predictive validity of early novelty preferences for 12 samples of children. Each of the 12 samples have yielded significant associations between early novelty preferences and later intelligence. Specifically, preferences for visual novelty during infancy have yielded moderate predictive validity coefficients ranging from 0.33 to 0.66 across the 12 samples with a mean of 0.44. Notably, these associations between early novelty preferences and later IQ appear to be of equal magnitude for intelligence measured at various points from 2 through 7 years. In contrast, conventional tests of infant intelligence based on sensori-motor functioning (e.g., Bayley, 1969) yield associations with later IQ which eventually decline to zero over the same time period. The conclusion that predictive validity coefficients based on early novelty preferences remain high from one later age to another, however, has been drawn from data obtained on independent samples. Each sample was tested at one point during infancy and again at only one later age. A more straightforward test of the stability of predictive validity estimates based on infant novelty preferences would be obtained by repeating intelligence tests from one age to another for the same sample of children. In the present study, a group of children originally tested for novelty preferences at 7 months and for performance on the Peabody Picture Vocabulary Test (PPVT) of intelligence at 3 years (Fagan, 1981; Fagan & Singer, 1983) were revisited at 5 years and again given the PPVT to determine if prediction from performance at 7 months to 5 years would remain at the same level as prediction from 7 months to 3 years. The present study was also concerned with the question of the basis of intellectual continuity over age. The empirical demonstration of continuity between early novelty preferences and later intelligence raises the theoretical question of the basis for such continuity. Fagan and McGrath (1981) adopt the working hypothesis that continuity over age in cognitive functioning reflects continuity in the same processes from age to age (e.g., the infant with advanced perception and memory processes is the child with such advanced processes). If so, the task of deciding what provides continuity in intellectual functioning becomes one of identifying similar processes underlying early novelty preferences and performance on later intelligence tests. Similar processes underlying two performance domains may be specific or general. Novelty preferences, for example, are typically taken as a working definition of infant visual recognition memory (e.g., Caron & Caron, 1968; Fagan, 1970). Perhaps the link between early novelty preferences and later performance on intelligence tests is specifically due to recognition memory. In other words, recognition per se may be related to intelligence at any age. Hence, the association between early novelty preferences and later intelligence may be mediated by a commonality in recognition memory functioning from age to age. Perhaps early novelty preferences and later recognition memory involve more of
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the same processes than are common to early novelty preferences and later intelligence. If so, we would expect that the association between early novelty preferences and later tests of recognition memory would be greater than the association between early novelty preferences and later intelligence. An alternative hypothesis is that the association between early novelty preferences and later intelligence is more general than simply a common link via recognition memory. In other words, there may be a more general association between early novelty preferences and later intelligence which involves a variety of similar cognitive and, perhaps, motivational processes. If so, the relationship between early novelty preferences and later intelligence would be greater than the association between early novelty preferences and later recognition memory. To decide between these specific or general hypotheses regarding the basis of intellectual continuity, children in the present study, tested for novelty preferences at 7 months, were administered tests of visual recognition memory as well as a test of intelligence at 5 years. Such a design allowed us to determine whether infants' preferences for visual novelty would be more highly associated with later visual recognition performance or with later intellectual level. METHOD The sample included 36 children (18 males, 18 females: 29 whites, 7 blacks) bom at term, who resided in suburban, middle-class neighborhoods. Each child was tested for novelty preferences at 7 months of age (29 weeks) on three pairings of achromatic face photos. Infants were asked to discriminate pairs of white women one from the other (two such tests) and to differentiate between two white babies. Specifically, for each of the three sets of photos, an infant was allowed to study a photo until 20 s of fixation had accumulated. Following study, the previously exposed face was paired with a novel face for two, 5-second test periods, with left-right positions of novel and familiar targets reversed from one 5-second period to the next. At 3 years the children were given the Peabody Picture Vocabulary Test (Form L) and two tests of immediate recognition memory: one test for 27 abstract patterns and one test for 27 unfamiliar cartoon faces. Examples of the abstract patterns and cartoon faces employed for recognition testing are given in Fagan (1984). For each recognition test (abstract patterns and cartoon faces) material was divided into spans ranging from two through seven items. A child was allowed to view each item within the span for 5 s. Following the study, the child was shown each previously exposed item paired with a novel item and was asked to point to the familiar item. Testing continued until all spans (in ascending order) within each type of material (patterns and faces) had been attempted. The persons administering tests at five years were not aware of the child's performance either at 3 years or at 7 months. Testers at 3 years had not known how the child had performed as an infant. The 36 children in the present sample
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were part of a larger group of 68 children seen at 3 years (as reported in Fagan, 1981; Fagan & Singer, 1983). The 36 children were also members of a sample of 52 children (the 16 additional children had not been tested at 7 months or at 3 years) seen at 5 years who were given tests of intelligence and recognition memory (as reported in Fagan, 1984). RESULTS Each child received three types of scores: a novelty preference score obtained during infancy and defined as the median percent of total fixation paid to novel targets over three tests; intelligence test scores based on the PPVT administered at 3 and at 5 years; and three recognition memory scores at 5 years, one for abstract patterns, one for cartoon faces, and one for both recognition subtests combined. The mean novelty preference score obtained by the sample at 7 months was 59.6% (SD = 11.9) with a range from 41 to 89). An estimate of the internal consistency of the novelty preference score was based on the mean intercorrelations among the three novelty problems according to a formula provided by Jensen (1980, Formula 7.1, p. 261). The resulting reliability coefficient of .32, while low, was in the range obtained in previous studies of early novelty preferences (Fagan & McGrath, 1981; Fagan & Singer, 1983) and was expected on the basis of the small number of tests (three) on which the median novelty preference score was based. The mean PPVT-IQ at 3 years for the sample was in the average range at 97.6 (SD = 16.9), with scores ranging from 65 to 135. The mean PPVT-IQ attained at 5 years by the same children was 105.8 (SD = 15.6) with a range from 76 to 136. Although it is not of interest in the present study, the increase in IQ from 3 to 5 years was most likely due to the use of Form A of the PPVT at 3 years and Form L at 5 years. The alternate form reliabilities of the PPVT at 3 years and at 5 years, as given by the authors of the test, are 0.75 (Dunn, 1965) and 0.80 (Dunn & Dunn, 1981), respectively. In the present sample, test-retest reliability from 3 to 5 years for PPVT-IQ scores proved to be high at 0.73. The recognition tasks at 5 years were of moderate difficulty with a mean total score (across tests for abstract patterns and for faces) of 43.3, SD = 7.0, out of a maximum possible score of 54, with individual scores ranging from 25 to 54. Recognition for abstract patterns (M 21.4, SD = 3.8) proved to be equivalent to recognition for cartoon faces (M 22.8, SD = 3.6). Individual differences in memory for patterns were highly related to memory for faces at r = .76, a value which may be taken to indicate the alternate form's reliability of the overall recognition test. One purpose of the present study was to discover if associations between early visual novelty preferences and later intellectual functioning would remain at the same level from 3 years to 5 years. The correlation between 7-month novelty
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preference and 3-year PPVT scores yielded a coefficient of 0.42 (df 35, p < .01), a value similar to the value of 0.36 obtained from the entire sample of 68 children from whom the present 36 subjects were drawn (Fagan & Singer, 1983). The relationship between 7-month novelty scores and 5-year PPVT-IQ was identical to that found between 7 months and 3 years at 0.42 (df35, p < .01). Neither of these two correlation coefficients of 0.42 exceeded the maximum coefficient possible given the reliabilities of the tests involved. At 3 years a maximum correlation of 0.49 was possible (obtained by multiplying the square roots of the reliabilities of each test by one another, assuming reliabilities of 0.32 for novelty tests and 0.75 for 3-year PPVT scores) and at 5 years a maximum of 0.51 was possible (given reliabilities of 0.32 for novelty scores and 0.80 for 5-year PPVT scores). In short, the level Of prediction from novelty preferences obtained at 7 months remained as high to 5-year IQ scores as it had to 3-year IQ scores, within the same sample of children. A second goal of the present study was to determine if infants' preferences for visual novelty would be more highly related to intellectual level at 5 years or to visual recognition performance at 5 years. As noted above, early novelty preferences were significantly associated with PPVT-IQ scores at 5 years at a value of 0.42. The association between early novelty preferences and recognition memory performances (total scores) at 5 years, however, was not reliably greater than chance at r = .23. The appropriate statistical test for the difference between the obtained values of 0.42 and 0.23 was problematic since one value (0.42) was significantly greater than zero and one value (0.23) was not significantly greater than zero. The analysis was further complicated by the fact that each value was severely attentuated by the low reliability (0.32) of the infant novelty preference test. The solution involved two steps. The first was to correct each correlation for attenuation due to unreliability (assuming reliabilities of 0.32 for early novelty preference scores, 0.76 for recognition testing at 5 years, and 0.80 for PPVT scores at 5 years) which yielded values of 0.83 and 0.46 in place of 0.42 and 0.23, respectively. The second step was to compare this value of 0.83 to that of 0.46 which yielded a Z score of 4.02, indicating an highly significant difference (p < .001) between the two coefficients. In addition, it should be noted that the low correlation between novelty preferences and later recognition performance did not appear to be a statistical artifact. Statistically, a value as great as that between novelty preferences and IQ was possible for the relation between novelty preferences and later recognition. In other words, the maximum coefficient between novelty scores and recognition scores could have reached 0.49, given the reliabilities of each test. The low correlation between early novelty scores and later recognition could also have been due to the fact that novelty preferences were based on distinctions among faces while later recognition tests included discriminations among abstract patterns as well as among faces. Such a possibility was ruled out by the fact that prediction from early novelty preferences to later recognition for faces was just as poor (r = .21) as prediction from early
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novelty scores was to later recognition of abstract patterns (r = .20). In short, early novelty preferences appear to be more highly related to later intelligence quotients than to later recognition performance and such a pattern of relationships does not appear to be artifactual. A final set of analyses sought to uncover any relationships between the sex, birth order, or level of parental education of the children and their verbal intelligence at 5 years. Two significant relationships emerged from the analysis. PPVT-IQ at 5 years was predicted by birth order (r = - . 3 0 , df35, p < .05) and by level of parental education (r = .39, df35, p < .01). Children earlier in birth order were brighter than later borns and the higher the level of parental education, the higher the child's IQ score. Such relationships, of course, are not surprising. They take on additional value in the present study, however, because neither was significantly related either to each other (r = .25) or to another predictor of 5-year IQ, i.e., novelty preferences at 7 months (correlations of - . 0 2 and .20 between novelty scores and birth-order and between novelty scores and parental education, respectively). A multiple regression analysis yielded an R value of 0.65 when 7-month novelty scores, birth-order, and level of parental education were combined to predict 5-year IQ scores. The point of such an analysis is not to show that any of these predictors of IQ is superior to the other, but only that predictors representing independent sources of variance can be combined to yield a more accurate estimate of later intellectual level. DISCUSSION In the present study, a group of children originally tested for visual novelty preferences at 7 months and seen for estimates of intelligence at 3 years were revisited and tested for intellectual functioning at five years. Prediction from performance at 7 months to 5 years was significant and remained at the same level as prediction from 7 months to 3 years, r = .42 at each point. In addition, it was shown that data on early novelty preferences could be combined with information on birth-order and parental education to achieve good prediction (R = .65) of 5-year IQ scores. Thus, the present results add to the accumulating literature on the prediction of later IQ from early visual novelty preferences in two ways. First, the present results show that correlation coefficients based on early novelty preferences remain stable over age in a longitudinally-studied sample. Second, these results add to the evidence (Fagan & Singer, 1983) that such coefficients can be combined with other correlates of intelligence to arrive at more accurate predictions of later intelligence. The present study was also concerned with the question of the basis of the continuity between novelty preferences and later intelligence. Given that novelty preferences are typically taken as a working definition of infant visual recognition memory, a simple hypothesis was tested in the present study. The hypothesis was that the association between early novelty preferences and later intelligence
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is mediated byrecognition memory, i.e., that recognition, per se, is related to intelligence at any age. If so, the expectation was that the association between early novelty preferences and later tests of recognition memory would be greater than the association between early novelty preferences and later intelligence. In fact, in the present study, quite the opposite occured. The relationship between early novelty preferences and later intelligence (r = .42) was statistically significant and greater than the statistically nonsignificant association between early novelty preferences and later recognition memory (r = .23). Perhaps the difficulty with our original hypothesis lay in the assumption that recognition memory is associated with intelligence at any age. One might conjecture that early recognition memory (as indexed by novelty preferences) is, indeed, a valid measure of early intelligence (and, hence, related to later intelligence), but that later recognition memory has little to do with later intelligence, perhaps because recognition, with age, becomes a highly automatic process. Such a notion would lead us to expect a low or zero correlation between early novelty scores and later recognition performance, such as was found in the present study. At the same time, such a notion would also predict a low or zero correlation between later IQ scores and later recognition performance. In the present sample, however, recgonition scores (totals) were highly related to 5year PPVT-IQ at r = .66 (df 35, p < .005). In effect then, while it is the case that recognition memory functioning at later ages is related to intelligence, it is not the case that early novelty preferences predict later intelligence because novelty preferences are an early measure of recognition memory. The present results tell us that the association between early novelty preferences and later intelligence is more general than simply a common link via recognition memory. But the question as to which processes constitute the association between early novelty preferences and later intelligence still remains. The answer to such a question requres the breakdown of early novelty preference tests and later intelligence tests into components and an analysis of the relations of the components in each task one to another. For example, consider some of the processes set into motion when a child is required to point to the correct picture when asked to identify the word " b u s " on the Peabody Picture Vocabulary Test. The child must note particular attributes (e.g., size, shape, function) common to the subset of vehicles we know as buses. He must also note features distinguishing buses from other vehicles. In addition, the detection of invariant features forming a pattern is necessary so that the object (bus) is identified as such despite changes in perspective, i.e., front, back, side, etc., and so that a picture or a line drawing of a bus is treated as similar to an actual bus. Finally, the word " b u s " must evoke the mental representation or prototype formed by past abstraction of the features common to buses. While the child answering questions on the PPVT must invoke such processes, it is also the case that the infant, in responding to visual novelty, may also reveal the working of those same processes. Specifically, studies of visual responsiveness to novelty have shown that the infant sepa-
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rates attributes, notes invariants in f o r m o v e r transformations in perspective, sees similarities across different representations, and can f o r m prototypes (see r e v i e w by Fagan, in press). In short, it is possible that s o m e o f the specific c o m p o n e n t s i n v o l v e d in solving p r o b l e m s on intelligence tests m a y also be studied by varying the conditions under which an infant is asked to demonstrate a preference for visual novelty. The study o f the relations o f such early and later processing to each other lies ahead.
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