The Effects of Aging and First Grade Schooling on the Development of Phonological Awareness

The independent influences of aging and schooling on the development of phonological awareness were assessed using a between-grades quasie.xperimental design. Both schooling (first grade) and aging (5-7 years] significantly improved children's performance on tests of phonemic segmentation, hut the schooling effect was four times larger than the aging effect. The schooling ^.ff^ct »'«-y attributed to format reading instruction, whereas the aging effect probably reflects natural maturation and informal exposure to written language. These data support a strong mutual relation between reading acquisition and phonological awareness. Phonological awareness is the ability to recognize the internal phonemic structure of spoken words. It is usually assessed by testing the subjects' ability to isolate and manipulate individual phonemic segments in words. Although a child makes phonemic distinctions as soon as he or she can understand and produce speech, the ability to manipulate phonemic segments consciously develops only around the first grade. For example, Liberman, Shankweiler, Fischer, and Carter (1974) found that no prekindergarteners, only 17% of kindergarteners, but 70% of the first graders were able to parse words into phonemes. The significant improvement in phonological awareness in first graders may be primarily ascribed to one of two factors (which are not mutually exclusive): (1) cognitive-linguistic skills that mature at about the age of six, independent of formal reading instruction (Bradley & Bryant, 1983); or (2) learning to read in an alphabetic orthography (Berteison. Correspondence and reprint requests to Shiomo Bentin, Department of Psychology, Hebrew University, Jerusalem 91905. Israel. E-Mail KPUSBCsHUJIVMI. Morais, Alegria, & Content, 1985). In contrast to speech, where phonemes are coarticulated and overlap in the acoustic stream. In writing the phonemes are represented by clearly defined orthographic segments, the letters (see Liberman & Mattingly. 1989). As children learn about letter-sound correspondence when they learn to read, it seems likely that they become aware that words are formed of the sounds that the letters represent. Owing to the impossibility of experimenting with school attendance, the effect of reading instruction on phonological awareness has been investigated only indirectly in studies that have relied on natural variation. Most of these studies suggested that learning to read triggers, or at least promotes, the development of phonological awareness. For example, adults who learned to read in adulthood were superior to illiterate adults on tests of phonemic segmentation (Morais. Cary, Alegria, & Berteison. 1979: Morais. Castro, Scliar-Cabral. Kolinsky, & Content, 1987). In Chinese, Read, Zhang. Nie, and Ding (1986) found higher phonological awareness in subjects who learned to read the alphabetic (pinyin) orthographic system than in subjects who read only the logographic system (kanji). Equivalent results were found comparing reading instruction methods; children who learned according to the "analytic" (segmental) method performed better on tests of phonemic segmentation than those who learned by the "global" (holistic) method (Alegria, Pignot, & Morais. 1982). However, while the studies cited suggest that literacy influences the development of phonological awareness, they do not prove this claim. The caveat is a possible confounding of differences in the extent or method of reading acquisition with other variables that may have influenced phonological awareness (e.g.. the amounts of informal linguistic experience). Therefore, there is still a need to specify the effect of schooling in general, and reading acquisition in particular, on the improvement in phonemic segmentation ability in the first year of schoohng. The present study circumvents the confounding problem by utilizing a quasiexperimental paradigm that allows for the post hoc disentangling of the effects of age and schooling (Cahan & Davis. 1987). This approach entails administration of the same test to at least two adjacent grade levels and takes advantage of the school cutoff that is imposed in most countries. The overall cross-sectional increase in mean test scores as a function of age is decomposed into within-grade and betweengrades segments that can be attributed to age and schooling effects, respectively. Theoretically, this goal could be achieved by comparing children born one day before the cutoff with children born one day after (Morrison. 1988); those children will differ by only one day in age. but by a full year of schooling. Similariy. children who are born on the first and the last days of one schooi year will differ in age by a full year while being in the same grade. Unfortunately, this approach suffers from a serious shortcoming of selection, because the cutoff is never strictly imposed. Moreover, those exceptions are not random: Children who are pushed ahead are usually intellectually advanced, whereas those who are held back tend to be underdeveloped. Such selective misplacement leads to overestimation of the schooling effect (Cahan & Cohen, 1989). A possible solution to the selection problem Is to base the estimation of age and schooling effects on the predicted (rather than empirically obtained) mean test scores ofthe youngest and the oldest children in each grade. Prediction would be based on the regression of test scores on chronological age across the entire legal age range in that grade, excluding the selection-tainted birthdates near the cutoff. This idea underlies the recently proposed between-grades regression discontinuity design (Cahan & Davis. 1987). ln the present study we applied this design VOL. 2, NO. 4, JULY I99I Copyright € 1991 American Psychological Society 271 PSYCHOLOGICAL SCIENCE Dc\elopmct>l o( Phonological Awareness to the estimation of the independent effects ot" one year of schooling (during which reading acquisition was the primary curricular activity) and one year of aging on the development of phonological awareness as evidenced by tests of phonemic segmentation.