Memory & Cognition 1990, 18 (5), 528-536 The relation between syllable number and visual complexity in the acquisition of word meanings

MICHAEL H. KELLY University ofPennsylvania, Philadelphia, Pennsylvania and KEN SPRINGER and FRANK C. KEIL Cornell University, Ithaca, New York

Four experiments were conducted to explore the correlation between syllable number and visual complexity in the acquisition of novel words. In the first experiment, adult English speakers in­ vented nonsense words as names for random polygons differing in visual complexity. Visually simple polygons received names containing fewer syllables than visually complex polygons did. In addition, analyses of English word-object pairings indicated that a significant correlation be­ tween syllable number and visual complexity exists in the English lexicon. In Experiments 2 and 3, adult English speakers matched monosyllabic novel words more often than trisyllabic novel words with visually simple objects, whereas trisyllabic matches were more common for visually complex objects. Experiment 4 replicated these findings with children, indicating that the as­ sumption of a correlation between word and visual complexity exists during the period of intense vocabulary growth. Although the actual correlation between syllable number and visual com­ plexity is small, other posited constraints on word meaning are also limited in strength. However, an increasing number of small, language-specific word-meaning correlations are being uncovered. Given the documented ability of speakers to detect and use these subtle correlations, we argue that a more fruitful approach to word-meaning acquisition would forgo the search for a few broad, powerful word-meaning constraints, and we attempt to uncover individually weak, but perhaps jointly powerful word-meaning correspondences.

Throughout the centuries, introspections on the acqui­ father points to a glass of liquid while saying to his daugh­ sition of word meanings have identified ostensive defini­ ter "water." Even assuming that the child is actually look­ tion as the prototypical naming game. An adult directs ing at the water rather than the television, her doll, or a child's attention toward a certain region of the visual the family dog, inferring correctly what her father means scene while simultaneously muttering some word or by "water" would seem to be quite unlikely. The same phrase. The child then infers that this sound is the lin­ situation is consistent with other hypotheses, such as that guistic symbol for the relevant feature of the visual scene, "water" means "container," "clear container," "any and encodes the associated pair into memory. Ifthe child clear liquid," "liquid-in-a-glass," "glass-containing-liq­ can correctly perform this inference once during every uid," "currently-unbroken-glass," "daddy's-liquid," or 1 or 2 waking hours between the 1st and 5th years of age, an infinite number of other interpretations. Through time­ a normal kindergartener's vocabulary will be attained consuming experimentation, one could test specific (Carey, 1982). hypotheses, but, as Quine points out, the elimination of This apparently simple and intuitively workable nam­ some hypotheses would still leave an infinite remainder ing game has received extreme criticism over the last three consistent with the gathered data. decades. Quine (1960) in particular argued that pointing Despite the apparent insurmountability of Quine's toward an object while speaking a word or phrase does (1960) arguments, a critical fact forces one to accept the not imply an obvious inference about the meaning of the ultimate feasibilityof ostensivedefinition: It is clearly used utterance. For instance, consider a situation in which a between parent and child as well as among adults, and it seems to produce valid inferences about word mean­ ings in the learner. This teaching method is so salient that This research was supported by NIH Grant 1 R29 HD23385-01 philosophers as diverse in doctrine as Augustine and awarded to Michael H. Kelly and NSF Grant BNS-81-02655 awarded Locke have accepted ostensive definition as the obvious to Frank C. Keil. Thanks are extended to Caroline Fryd-Schechter and method of acquiring word meanings. This observation has CheryI Pfeiffer for assistance in running Experiments 1-3, and to Michael steered many investigators away from responding to McCloskey, Arthur Samuel, and three anonymous reviewers for help­ Quine's dilemma by searching for a radically different ful comments on previous drafts of this paper. Correspondence should be addressed to Michael H. Kelly, Department of Psychology, Univer­ approach to meaning acquisition. Instead, researchers sity of Pennsylvania, 3815 Walnut Street, Philadelphia, PA 19104. have attempted to uncover constraints that human beings

Copyright 1990 Psychonomic Society, Inc. 528 SYLLABLE NUMBER AND VISUAL COMPLEXITY 529 impose on the types of hypotheses considered in infer­ ,'krigias" before inferences about other aspects of the ring a word's meaning. By sufficiently constraining the meaning could be made. In addition, constraints have nature of these hypotheses, an account of word-meaning generally been discussedas though they were intrinsicto acquisitionmight be proposed that recognizesour exten­ the linguistic domain, rather than deriving from more sive use of ostensivedefinition, as well as Quine's objec­ generalcognitive organizing principles. For instance, the tions to traditional analyses of its implementation. mutualexclusivity constraint may reflect a more general The typesof constraints positedthus far havebeenquite assumption that the elementsof two domainsare mapped heterogeneous, carving out different domains of in one-to-one correspondence. This relatively abstractas­ hypotheses about word meanings. However, these con­ sumption may influence cognitive development in areas straints are generally cast in the form of assumptions or otherthanlanguage, suchas mathematical reasoning (Gel­ presuppositions about how languagesmap onto the con­ man & Gallistel, 1978). ceptual and physical worlds.They are thereforelanguage­ In this paper, weexplorea potential constraintthatdoes neutral, and so they posit assumptions shared by all lan­ not depend on the previous acquisition of some word guage learners and users. Markman (1987) has inves­ meanings. The constraint that we willdiscuss possibly de­ tigated whatshe calls "the mutual exclusivity" constraint, rives from a bias to assume that two domains are posi­ whichrests on the assumption that a singleobjectwill not tively rather than negatively correlated. In other words, be represented by more than one word (though a single whenrelating twodomains, peopletend to align the high­ word could map onto multipleconcepts, as in fbif). This magnitude regionof one domainwiththe high-magnitude constraint is similarto Clark's (1983) lexical contrastthe­ region of the other domain. For example, subjects in ory, althoughClark argues that two words may have the cross-modality matching experiments tendto associate in­ sameextension, as long as they havedifferent intensions, creases in brightness with increases in loudness, and vice however slight (e.g., the formality contrast between cop versa (Stevens & Marks, 1965). This association does not and policeman). In practical terms, the mutual exclusiv­ depend on the direct perception of brightness and loud­ ity constraint impliesthat if a child has a word for a par­ ness, but can be mediated linguistically. Thus, thunder ticularcategoryof objects, then this class will not be con­ is rated as louder when it appears in the synesthetic sidered as a candidate for the meaning of a new word. metaphor bright thunder than when it appears in the Children do seem to follow this prediction in makingin­ metaphor dim thunder (Marks, 1982). The adjectives used ferences about word meanings. When presentedwith one to describe luminosity in the visualdomaincan therefore object whose name is known and another whose name is modify the inferences one makesaboutprobableloudness unknown, children prefer to pair a novel word with the in the auditorydomain, and the directionof the inference object currently lacking a name. reflects the assumption thatthe twodomains are positively Keil (1979) has proposed that children and adults as­ correlated. sume that a word's meaning will not conflate different In this paper, we will explore the potential relevance ontological categories. Thus, if a childhearsa wordpaired of this generalpositive-correlation bias to word-meaning witha predicate associated withplants,they willthencon­ acquisition. In particular, we willexaminewhetheradults sider as nonsensical or anomalous eventpredicatespaired and children prefer to map visuallycomplexobjectsonto with the term. For example, when told that "krigias complex words and visually simple objects onto simple bloom," 5-year-oldchildrenacceptedthe possibility that words. Visual complexitywill be measured by observer krigiascoulddie, whileat the sametimerejecting the pos­ ratingsof complexity for familiarand noveldesigns. The sibility thatkrigias couldhappen on Saturday (Keil, 1983). number of syllablesin a word will be considereda mea­ On the other hand, whentoldthatkrigiascouldbe an hour sure of wordcomplexity, withmore syllables correspond­ long, the childrenaccepted "Krigias happen on Saturday" ing to greater complexity. Given that greater complexity as sensible, but rejected "Krigias die." Children assume generally entails more difficult processingand concomi­ that events and plants are nonoverlapping sets, and that tant performance deficits, variations in syllable number word meanings will reflect this division. do appear to be related to variations in processing com­ Though apparently used by children (and presumably plexity. For instance, wordswithmanysyllables are more adults) in constraining word-meaning hypotheses, the difficult to recallfrombothimmediate memory (Baddeley, mutual exclusivity and ontologicalprinciples are limited Thompson, & Buchanan, 1975) and long-term memory in that the child must already possess a rudimentary (Bock, 1982). In addition, polysyllabic words appear to vocabulary beforethey can be applied.Thus, withoutany be more susceptible to speech errors than monosyllabic word-meaning pairs previously established, the mutual ex­ words. For example, in a corpus of 183 malapropisms, clusivity principle offers no means of constraining the or one word inadvertently replacing an intended word hypothetical meanings for the first word encountered. In­ (e.g., saying "remedy" for recipe), only 26% involved deed, the constraint would not be very powerful even if monosyllabic words(Fay & Cutler, 1977). Giventhe fact a small set of word meanings were known, since few that monosyllabic words are of relativelyhigh frequency potential meanings for a new word could be eliminated (Zipf, 1965), they would have many more opportunities from consideration. In Keil's (1983)ontologicalstudies, than polysyllabic words to be involvedin a speecherror. children had to be literally given a partial meaning for The dominanceof polysyllabic words in sucherrors sup- 530 KELLY, SPRINGER, AND KEIL ports the claim that they are more complex than monosyl­ the physical object category (a geographical location) and labic words. However, it should be emphasized that these the abstraction category (a government or political sys­ complexity effects are not by necessity intrinsically lin­ tem). If such conflations are widespread, then language guistic. Rather, any relatively long motor pattern would learning will not be aided, or may even be hindered, by in general be more difficult to prepare and produce than the assumption that the meaning of a word will map onto a shorter pattern, and any relatively long acoustic signal a single ontological category (see Keil & Kelly, 1986, for would in general place greater demands on memory than a reply to Carey's critique). would a shorter signal. For the complexity constraint to aid the acquisition of Given these measures of word and visual complexity, word meanings, languages in general, and language four experiments were conducted to address three ques­ speakers in particular, must tend to assign words to ob­ tions. First, is there a correlation between the visual com­ jects according to their relative complexities. We first con­ plexity of objects and the words speakers invent to denote ducted a correlational investigation of this issue by com­ those objects? Second, do adult listeners map polysyllabic paring visual complexity ratings for pictures in the words onto visually complex objects rather than visually Snodgrass and Vanderwort (1980) picture norms with the simple objects? Finally, do children also assume that com­ lengths of their corresponding English words in syllables. plex words will be used to denote visually complex ob­ These data were collected by the original investigators, jects? The first question bears on the issue of whether lan­ and so lexical and pictorial selection could not have been guage users are at least partially correct in assuming a biased by the hypothesis under investigation here. For the correlation between word complexity and visual complex­ 260 pictures used in the norms, we correlated the mean ity. This question was addressed in Experiment 1 by visual complexity ratings for each picture with the num­ presenting adults with drawings of unfamiliar designs ber of syllables found in the most common name given varying in complexity and asking them to invent new to the picture by Snodgrass and Vanderwort's subjects. words for the objects. The basic prediction was that the A small, but significant, correlation of .20 (p < .02) was invented words should consist of more syllables when used found between visual complexity and syllable number, to denote visually complex rather than visually simple ob­ with number of syllables increasing with complexity. jects. The second question was addressed in Experiments These results thus indicate that the number of syllables 2 and 3, in which adults were presented with paired draw­ in English words is significantly correlated with the rated ings of familiar or unfamiliar objects. One member in each visual complexity of their referents. Of course, many pair was visually more complex than the other. The sub­ potential covariates remain unexplored, so that we have jects were then presented with two words varying in syl­ no direct evidence that individual speakers generally tailor lable number, and they were asked to pair each word with their naming habits to fit the complexity of objects named. one of the two objects. Once again, the complexity con­ The correlation is just as consistent with the hypothesis straint predicted that the visually complex object would that ratings of visual complexity are affected by the names be more likely than the simple object to be paired with of the rated objects. In Experiment 1, we addressed these the longer word. Finally, the third question was explored issues by presenting adult English speakers with a set of by asking children to pair words with objects, with the unfamiliar designs. Subjects were asked to play •'Adam," prediction that visual complexity would be matched with and invent a name for each object. Some of the objects word complexity. I were visually more complex than others, and we explored whether names invented for the complex objects contained EXPERIMENT 1 more syllables than the names invented for the simple ob­ jects. Unfamiliar, randomly constructed designs were used There are two sides to the question of whether or not to reduce any effects that might derive from knowledge human beings assume that simple words will map onto of the particular objects, such as animacy, prototypical­ simple objects. The first issue concerns the language ity, or age of learning. learner or perceiver, and derives most directly from Quine's (1960) problem. In particular, when a person Method hears a new word and tries to infer its meaning, are the Subjects. Sixteen members of the University of Pennsylvania inferences affected by the complexity of the word? This community were paid $2.00 each for their participation in this 15-20 min experiment. All subjects were native English speakers. question focuses on the types of a priori hypotheses that Materials. Randomlyconstructed, unfamiliar designs were made learners or perceivers bring to word-learning situations. by modifying slightly a drawing method introduced by Attneave The second, equally critical, issue concerns the language (1957) for studiesof visual complexity. The process consistsof ran­ producer, and focuses on the validity of word-meaning domly selecting a specified number of locations on a grid, and then constraints. A particular constraint on word-meaning connectingthe locations or "dots" by straight lines to create a ran­ hypotheses would not be of help if the lexicon being dom polygon. Locations were connected according to proximity, learned were not governed by the constraint. For exam­ subjectto the constraint that lines could not cross, and that the num­ ber of edges in the final drawingequaledthe numberof dots selected. ple, Carey (1986) has argued, contrary to Keil (1979), Attneave found that number of edges predicted rated complexity that word meanings often conflate ontological categories. far better than any other variable analyzed (e.g., symmetry). There­ Thus, words like Italy possess two meanings that confound fore, in this study, we created two categories of random polygons, SYLLABLE NUMBER AND VISUAL COMPLEXITY 531 with 7 or with 15 edges; figures in the latter category were con­ Table 1 sidered to be more complex. Numbers of Simple and Complex Figures That Received Names Eight 7-edged and 8 15-edged random polygons were created for of Different Syllable Numbers in Experiment I ---~---- the study. The figures were created on a Macintosh Plus computer, Number of Syllables using the graphics program MacPaint. After the contours of the Figure 2 3 4 5 6 figures were drawn, the interiors were filled with solid black. Print­ .-_._-_._.._-~-----_._-- 54 10 5 2 0 outs of the figures were used in the experiment, and two exam­ Simple 57 Complex 31 76 16 2 2 I ples, one complex and one simple, are shown in Figure I. The 16 polygons were arranged in two orders, with the first order deter­ mined randomly and then reversed to form the second order. Eight subjects were assigned to each order. lables than did items in the simple category. The mean Procedure. The subjects were told that the experiment concerned number of syllables in names for complex objects was 2.0, the types of rules people use in naming objects. They were asked to imagine that they were modem "Adams" who had to invent whereas the mean for simple objects was 1.8. This differ­ names for unfamiliar figures. The names could be anything they ence was significant across both subjects [1(15) = 2.37, liked, as long as the names did not match a known English word. p < .05] and items [1(14) = 2.32, p < .05]. Although The first figure was then presented, andwhen the subject haddecided this difference is small, it should be pointed out that sub­ on a name, the subject's vocal response was tape-recorded for later jects very rarely invented words containing more than two analysis. The same procedure was then applied to each of the re­ syllables. Only 15% ofall responses contained more than maining 15 items. Scoring and data analysis. The responses were scored by two two syllables, and 41 % of these were produced by a sin­ raters, who were unaware of the complexity of the object named. gle subject. Because of this restricted range of responses, The raters noted the number of syllables contained in each word, any naming differences between the simple and complex and these were later categorized according to the particular figure figures would not be expected to be large. To illustrate being named and its complexity category. The subjects received the differences more finely, Table I shows the number two scores for each rater: the mean number of syllables used in of names given to simple and complex figures that con­ the names for simple figures, and the mean number of syllables used in the names for complex figures. Items received a single score tained I, 2, 3, 4, 5, or 6 syllables. As can be seen, the for each rater, corresponding with the mean number of syllables differences between simple and complex figures are not in the 16 names given to each item. Since all subjects received both due to a few outlier responses; they emerge in the distri­ simple and complex figures, the means of these categories were bution of mono- and disyllabic words. In particular, one­ compared, using within-subjects tests. However, since items were syllable words mapped onto simple objects 65% of the in either the simple or the complex category, they were compared time, but mapped onto complex objects only 42 % of the using between-items tests. time. Thus, listeners could make a reasonable inference about the referents of the monosyllabic and disyllabic Results and Discussion words invented by the speakers. The patterns of significance were identical for the two When coupled with the correlational analysis discussed raters, who agreed in 95% of their syllable judgments. earlier, these experimental results indicate that speakers For ease of exposition, therefore, we will report the results do indeed structure the names of objects in a way that from the rater who showed the smaller difference between reflects their complexity. Thus, in learning the meaning the simple and complex figures. As predicted, items in of a new word, a listener has some justification for as­ the complex category inspired names containing more syl- suming that relatively complex words will denote rela­ tively complex objects. It is interesting that the subjects in the naming study never referred to a complexity strategy in explaining how they went about the task. They generally reported giving the first word that came to mind. When told of the complexity hypothesis, they said that it made sense, but that they had not considered this pos­ sibility as the purpose of the study. This finding contrasts with the introspections of participants in the following two experiments, in which subjects were presented with non­ sense words and selected objects for which the words seemed appropriate names. The subjects frequently men­ tioned a complexity hypothesis in these experiments. However, the name-invention results suggest that visual complexity is related to word complexity even when this relation is not being explicitly considered at a conscious level. In addition, the appearance of a correlation between syllable number and visual complexity in an extremely Figure 1. Examples of random polygons used in Experiments 1, unconstrained task attests further to the significance of 3, and 4. this relation in mapping words onto meanings. 532 KELLY, SPRINGER, AND KEIL

EXPERIMENT 2 Table 2 Object and Pseudoword Pairs Used in Experiment 2 Given that languages pair complex words with complex Simple Object Complex Object Simple Word Complex Word objects to some extent, the next question focuses on Star Tree Dez Jalinbaf whether listeners use this rule as one heuristic when in­ Envelope Saltshaker Gorp Raminlak Hanger Glasses Parm Dordomak ferring the meaning of a word. In Experiment 2, adult Box Cake Dob Mordinlop English speakers were presented with pictures of familiar Moon Leaf Wid Peninod objects arranged in pairs. Within experimental, or target, Arrow Anchor Vid Vaniteg pairs, one of the pictures was rated more visually com­ Flag Crown Zop Zoybolam plex than the other, with a variety of other factors, such Seal Lobster Fot Tanopee Tomato Pineapple Blit Barodop as rated familiarity, controlled. The subjects were told Ball Doll Fim Ralopor that the objects portrayed are called by different names Knife Gun Sep Bovakus in different languages, and that they would be presented Truck Train Lish Saplomay with two such foreign names for each pair and be asked Pig Skunk Vorp Hanlomat Nose Eye Gisp Simlobat to guess which word "went best" with each object in a Bowl Stove Heb Lakintok pair. For example, one pair of pictures portrayed an an­ Drum Flute Yim Bindolay chor and an arrow, with the latter being rated as less visually complex than the former. The subjects were then given two pseudoword names for the objects, viti and vani­ perimental pairs. One monosyllabic and one trisyllabic pseudoword teg, and they had to guess the word that corresponded were randomly selected for each experimental pair, subject to the with each object. In this case, subjects were predicted to constraint that the initial phonemes of the pseudowords differ from pair vid with the arrow and vaniteg with the anchor more the initial phonemes of the real English words associated with the objects in each pair. Two disyllabic pseudowords were randomly than the reverse. selected for each filler pair, constrained in the same manner as the experimental pairs. The pseudowords assigned to the experimen­ Method tal pairs are listed in Table 2. Subjects. Twenty members of the University of Pennsylvania Procedure and scoring. The subjects were instructed that they community were paid $2.00 each for their voluntary participation would playa narning game, in which they would be presented on in the 15-20 min experiment. All subjects were native English each trial with drawings of two common objects and a pair of words speakers. spoken in a •'far-off country. " The words were used to denote the Materials. Twenty-six pairs of pictures were selected from the objects in that country, and the subjects had to guess which word Snodgrass and Vanderwort (1980) picture norms, with 16 pairs being went with which object. On each trial, the experimenter showed experimental items and 10 being filler items. These norms were the subject one index card with pictures of two objects. The ex­ selected because Snodgrass and Vanderwort obtained visual com­ perimenter would then read the two "foreign" words in a conjunc­ plexity and familiarity ratings for each picture. In addition, since tive phrase (e.g., "gorp and rarninlak"), and ask the subject to match subjects in their study had to name the pictures, we also know the the words with the pictures. The experimenter would note the sub­ most common name associated with each picture, and hence the ject's responses on a score sheet, and then begin the next trial. number of syllables it contains. The items in each experimental pair Both pseudowords used in filler pairs contained two syllables, differed in visual complexity, but they did not differ in rated familiar­ and the order in which they were spoken was determined randomly. ity. In addition, the most common English words denoting the ob­ One of the words used in experimental pairs contained one sylla­ jects in each pair contained the same number of syllables, and the ble whereas the other contained three syllables. The monosyllabic frequencies of these words, as determined by Kucera and Francis word was always spoken before the trisyllabic word. This order (1967), did not differ across the simple and complex pictures. Fi­ was selected because English speakers prefer words with few syl­ nally, 8 pairs portrayed objects from the same semantic category lables to precede words with more syllables in conjunctive phrases (e.g., nose and eye), whereas the other 8 portrayed objects from (Bock, 1982; Kelly, 1986), and we wanted to eliminate any possi­ different categories (e.g., arrow and anchor). The simple and com­ bility that an unnatural presentation of the pseudowords might in­ plex pictures in the former 8 pairs did not differ in prototypicality, duce unnatural responses. Since the visually simple object was por­ as determined according to the Battig and Montague (1969) category trayed to the left of the complex object for half the pairs and to norms. A complete list of the experimental pairs is presented in the right of the complex object for the other half, the consistent Table 2. The filler items were selected so that the pictures of each temporal order ofpseudoword presentation was uncorrelated with pair were denoted by words containing the same number of sylla­ the spatial order of picture presentation. bles. In addition, 5 of the filler pairs portrayed objects from the For each subject, the percentage of items in which the mono­ same semantic category, whereas the remaining 5 pairs showed ob­ syllabic word was paired with the visually simple object was cal­ jects from different categories. culated, and these values were used in the subjects analysis. The The pictures in each pair were pasted side by side on 3 x 5 in. scores used for the items analysis consisted of the percentage of index cards. The left-right order for each pair was determined ran­ subjects who assigned the monosyllabic word to the simple object domly, subject to the constraint that the visually simple object be for each experimental pair. placed to the left of the complex object for halfof the experimental and filler pairs, and to the right for the remaining half. The cards Results and Discussion were then randomly arranged with the restriction that no more than The results supported the predictions based on the com­ two experimental or filler items occur consecutively. Sets of 16 monosyllabic, 20 disyllabic, and 16 trisyllabic pseudo­ plexity hypothesis, as subjects paired the linguistically words were then invented, with the disyllabic pseudowords assigned simple word with the visually simple object on 65 % of to filler pairs and the mono- and trisyllabic words assigned to ex- the trials. Across both subjects and items, this asymmetry SYLLABLE NUMBER AND VISUAL COMPLEXITY 533 was significantly greater than a chance relationship be­ in top-bottom sequence on standard 8.5 x 4 in. computer sheets, tween word and perceptual complexity [subjects, t(19) = under the constraint that half of the experimental pairs have the simple object above the complex object and vice versa for the re­ 4.91, P < .001; items, t(15) = 2.59, p < .025). Only maining half. one of the 20 subjects paired the monosyllabic words with The 16 pairs of monosyllabic-trisyllabic nonsense words used the complex objects more than with the simple objects, in Experiment 2 were retained here and randomly assigned to the and only 3 of the 16 experimental pairs had a higher experimental pairs. The 10 pairs of disyllabic nonsense words used proportion of subjects making simple-word-complex­ in Experiment 2 were randomly assigned to the filler pairs. The object pairings rather than the reverse. pairs were then randomly arranged for presentation to the subjects, In their introspections on the criteria that they had used under the constraint that no more than two pairs of the same type to assign words to objects, the subjects often referred to appear consecutively. Procedure. The basic procedure used in Experiment 2 was a simple-word-simple-object strategy. However, it is not repeated here, with minor modifications related to the use of ran­ entirely clear that correctly inferring the hypothesis un­ dom polygons. The subjects were asked to imagine that they had der investigation is a confound, or whether it provides just landed on a new planet, which was furnished with strange ob­ more direct evidence for the existence of a naturally jects and whose inhabitants spoke an unfamiliar language. When preferred complexity constraint. Discussions of learning each pair of objects was presented, the experimenter spoke two word meanings are typically couched in problem-solving words in this language, which corresponded to the names of the objects. The subject was asked to pair each word with the object terminology, in which specific hypotheses are formed and that seemed to be its most appropriate name. The words in each tested. Whether these hypotheses are formulated with or pair were read in the order used in Experiment 2, and the ex­ without conscious awareness, the fact remains that one perimenter noted the subject's responses on a score sheet between can posit many hypothetical correlations between words trials. and meanings. In Experiment 2, for example, the sub­ For each subject, the percentage of items in which the mono­ jects could have decided to match simple words with com­ syllabic word was paired with the visually simple object was cal­ culated, and these values were used in the subjects analysis. The plex objects. It is certainly logically possible for an in­ scores used for the items analysis consisted of the percentage of verse correlation between syllable number and visual subjects who assigned the monosyllabic word to the simple object complexity to exist, and yet not a single subject mentioned for each experimental pair. this strategy when asked about how the task had been per­ formed. Given sufficient feedback about right and wrong Results and Discussion responses, subjects might eventually hypothesize that sim­ The results replicated Experiment 2, though the effects ple words map onto complex objects in some domain, but were much stronger with the random polygons than they this hypothesis seems to be less accessible or reasonable had been with the familiar objects. Subjects matched the than one relating simplicity to simplicity in word-meaning monosyllabic nonsense words with the seven-edged sim­ correspondences. The latter hypothesis emerges without ple polygons on 78% of the trials. This bias to relate word any corrective feedback, which would be expected from complexity with visual complexity was significant across a default type of strategy. both subjects [t(15) = 8.35, P < .0001] and items [t(15) = 9.93, P < .0001). As in Experiment 2, the results EXPERIMENT 3 were quite robust; not a single subject or item pair showed patterns opposite to those predicted. In Experiment 3, we attempted to obtain a "purer" test As in Experiment 2, subjects often noted the complex­ of the complexity hypothesis by using line drawings that ity hypothesis when explaining how they tried to perform did not correspond very readily to familiar objects. Thus, the task. Though we argue in the discussion of Experi­ any interference from knowing the English names of ob­ ment 4 that such fruitful detective work is not obviously jects was reduced, since the line drawings were nonsense a problem for the complexity hypothesis, and may even figures that lacked English names. be expected, such introspective success raises the ques­ tion of how powerful the hypothesis is when less con­ Method strained situations or less sophisticated human beings are Subjects. Sixteen members of the University of Pennsylvania involved. The first study partially addressed this caveat, community were compensated $2.00 each for their voluntary par­ ticipation in the study. All subjects were native speakers of English. since the naming task was much less constrained than the Materials. Fifty-two random polygons were created, using the matching task, and subjects did not report making con­ procedures described in Experiment 1. Twenty-six polygons con­ scious use of the complexity hypothesis. Nonetheless, the tained 15 edges, and were classified as complex, whereas the re­ results support the claim that speakers are biased to en­ maining 26 polygons contained 7 edges, and were classified as sim­ code visually complex with lexically complex patterns. ple. The 16 polygons used in Experiment I were retained here as However, all of these studies involved adult subjects, so part of the complete set. The polygons were randomly arranged they do not necessarily reflect the major language-learning into 16 experimental pairs and 10 filler pairs. The experimental pairs contained a 7-e

EXPERIMENT 4 difference suggests that the bias to pair visual stimuli with complex labels may be an early predisposition in the ac­ Method quisition of word meanings. Since the bias emerged more Subjects. Two samples of children ranging in age from 4 to 8 explicitly among adults, it might be inferred that the com­ years old were interviewed individually at their day-care centers plexity hypothesis is an initially unconscious bias that be­ in the Ithaca, New York area. Each sample was composed of 16 comes more "accessible" to central processing during children. The mean ages were 6 years, 10 months for Sample A and 6 years, 4 months for Sample B. cognitive development (Rozin, 1976). Materials and Procedures. The materials and procedures were exactly the same as those in Experiments 2 and 3 involving adult GENERAL DISCUSSION subjects. The children in Sample A matched pseudowords with familiar objects as described for Experiment 2, whereas the chil­ When inferring the referent of an unfamiliar word, both dren in Sample B matched pseudowords with random polygons, adults and children pair complex labels with complex as described for Experiment 3. figures. However, the results do not necessarily imply that human beings are predisposed to assume that a specific Results and Discussion correlation between word and referent complexity exists. The results of both procedures indicated that children, Rather, the results might be a manifestation of a general like adults, assume that word complexity is correlated with perceptual/cognitive tendency to align dimensions so that perceived visual complexity. Sample A matched the an increase in magnitude along one dimension implies an monosyllabic word to the visually simple object 60.2% increase in magnitude along another. This alignment al­ of the time, a bias that was significantly greater than lows people to scale increases in perceived brightness in chance across both subjects [t(15) = 2.51, P < .05] and terms of increases in perceived loudness and, perhaps, items [t(15) = 2.30,p < .05]. Only 3 of the 16 subjects increases in perceived visual complexity with increases paired monosyllabic words with complex objects more in perceived label complexity. Ifcorrect, then this general than with simple objects, and only 3 of the 16 items explanation for the results reported here should predict received more monosyllabic-complex mappings than analogous effects in structurally similar experiments. For monosyllabic-simple mappings. example, one would expect that complex auditory or tac­ As in the adult experiments, the results were stronger tile patterns as well as visual patterns would be related when the children matched the pseudowords with random to relatively complex words. (In fact, we have obtained polygons. The children in Sample B matched mono­ preliminary data consistent with these expectations.) syllabic words with the visually simpler, 7-sided polygons The complexity heuristic used by language perceivers on 65.6% of the trials. This asymmetry was significantly has some justification, since speakers inventing names for greater than chance across both subjects [t(15) = 4.60, novel figures create words with more syllables when dub­ P < .001] and items [t(15) = 3.91, p < .01]. Only 1 bing complex objects than when dubbing simple objects. subject paired monosyllabic pseudowords with IS-edged In addition, a comparison of actual English words with polygons more often than with 7-edged polygons, and only their referents revealed a significant correlation between three items received more monosyllabic-complex matches the number of syllables in the name and the rated visual than monosyllabic-simple matches. complexity ofthe referent. Nevertheless, the correlation One problem with these results is that they combine data between word and visual complexity was quite small, from children of quite different ages. This procedure which raises doubts about the power of the constraint, and might occlude important age effects. For instance, if the the wisdom of those who use it. Although the scope of strength of the complexity bias is positively correlated with the constraint appears to be restricted, serious limitations age, one might doubt that children follow the bias during plague other proposed word-meaning constraints as well. the early period of language acquisition. Yet we have ar­ Thus, both Keil's (1979) ontological constraint and Mark­ gued that the bias might be particularly important in early man's (1987) mutual exclusivity constraint cannot aid lan­ life because of the relative weakness of other types of guage acquisition until the child already knows the mean­ word-learning biases. In order to address this issue, we ings of some words. The complexity constraint is not correlated the age ofeach child in Samples A and B with limited in this way, for it can be used at the start of the proportion of complex word-complex picture matches vocabulary acquisition, although its power nevertheless they made. For the children presented with familiar ob­ seems small. jects, the Pearson correlation was .048, whereas for the One conclusion we may be forced to draw from this children presented with random polygons, the Pearson and other work is that few, if any, extremely powerful correlation was - .408, with neither of these correlations constraints on word meaning may exist. Rather, human reaching significance (p > .10 in each case). beings may have a large number of heterogeneous con­ In sum, children as well as adults assume that simple straints, some language-general, others language-specific, words, as defmed by syllable number, will denote visually but none with any great strength. The correct induction simple figures more often than visually complex figures. of word-meaning pairs may rely on the joint use of a Unlike the adults, however, none of the children expressed diverse set of heuristics, whose relevant domains may any explanation even vaguely resembling a complexity range from the phonological structure ofa word, as with hypothesis when asked to justify their responses. This the complexity constraint, to the morphological and syn- SYLLABLE NUMBER AND VISUAL COMPLEXITY 535 tactic environment in which a word is embedded. Brown's Finally, while generally focusing on language-neutral (1957) seminal discovery that children interpret words hypotheses about word-meaning relations, investigators with an -ing tagged on the end as denoting actions is an may have inadvertently underestimated the role of example of a morphologically defined constraint. The language-specific word-meaning relations, and the abil­ "theta criterion," which states that the underlying logi­ ity of children to detect them. However, a variety of cal structure of a verb is reflected in its surface argument studies have shown that many language-specific cues to structure (Chomsky, 1980), is an example of a syntacti­ a word's meaning or grammatical class exist, and that cally defined constraint. Thus, Landau and Gleitman speakers are amazingly adept at learning and using them. (1985) claim that the meaning of a verb can be inferred Thus, Kelly (1988) has shown that English speakers have from the set of syntactic structures in which it can ap­ implicit knowledge of the fact that English disyllabic pear. These constraints are limited in their generality as nouns tend to have primary stress on the first syllable well. In the Brown example, children must isolate the rele­ whereas disyllabic verbs tend to have stress on the sec­ vant morphological marker before it can be used as a cue ond syllable. Cutler, Norris, and Williams (1987) have to meaning, but children know the meanings of some demonstrated that English speakers have abstracted the words before this point. In order to use the argument fact that consonant-vowel sequences in English are more structure of a sentence to infer a verb's meaning, one must likely to have a CVCV rather than CVCC arrangement. already be able to differentiate nouns from verbs. The Finally, nominal gender categories in French are cor­ main point is that many quite diverse word-meaning related with certain word endings. Thus, masculine nouns heuristics have been proposed, and actually seem to be tend to end in -ais whereas feminine nouns end in -ssion. used, although they all are basically crutches leaning on Although not having conscious knowledge of these dis­ other crutches. Thus, an important goal for researchers tributional facts, French-speaking children clearly use in language acquisition will be to catalogue these many them when classifying unknown words into gender constraints and determine how they interrelate. categories (Tucker, Lambert, Rigault, & Segalowitz, The issue of interrelation could be crucial given that 1968). All of these correlations are probabilistic in na­ the scope or validity of an individual heuristic is small. ture, and, of course, they are not explicitly taught. In ad­ Ifthe relation between, say, the syllable number of a word dition, they are clearly language-specific. Yet speakers and the perceptual complexity of its referent is of limited of these languages have a remarkable facility at detecting validity, why divert attentive and inductive processes to them, and they can therefore make use of them when they this relation if an infinite number of other possible corre­ encounter new words. All of this research suggests that lations between linguistic and conceptual structure exist? many useful correlations between form and meaning ex­ One possibility concerns the appearance of a particular ist in language, and, though individually weak, together linguistic variable in other heuristics. Billman (1983) has they could help the child or adult make reasonably quick suggested that learners try to uncover the structure of a and accurate inferences about the meanings of novel domain such as language by searching for variables that words. appear in many rules. This procedure, called "focused sampling," claims that a particular rule will be uncovered most easily if its components participate in other rules as REFERENCES well. One possible reason for using the low, but present, ATTNEA VE, F. (1957). Physicaldeterminantsof thejudged complexity correlation between syllable number and visual complexity of shapes. Journal of Experimental Psychology, 53, 221-227. could be the appearance of syllable number in other corre­ BADDELEY, A. D., THOMPSON, N., & BUCHANAN, M. (1975). Word lations between linguistic structure and meaning. For ex­ length and the structure of short-term memory. Journal of Verbal ample, syllable number is correlated with grammatical Learning & Verbal Behavior, 14, 575-589. BATTIG, W. F., & MONTAGUE, W. E. (1969). Category norms for ver­ category in English, since verbs tend to contain fewer syl­ bal items in 56 categories: A replication and extension of the Con­ lables than nouns. Adult English speakers have detected necticut category norms, Journal of Experimental Psychology, 80, this correlation, and use it when implicitly categorizing (3, pt. 2). nonsense words as nouns or verbs. When asked to use BILLMAN, D. (1983). Procedures for learning syntactic categories: A nonsense words such as and in sentences, model and test with artificial grammars. Unpublisheddoctoral dis­ gorp raminlak sertation, University of Michigan. speakers are much more likely to use monosyllabic rather BOCK, J. K. (1982). Toward a cognitive psychology of syntax: Infor­ than trisyllabic words as verbs (Cassidy & Kelly, 1990). mationprocessingcontributionsto sentenceformulation. Psycholog­ In addition, syllable number is also correlated with pro­ ical Review, 89, 1-47. totypicality, since prototypical members of categories tend BROWN, R. (1957). Linguisticdeterminism and parts of speech. Jour­ nal of Abnormal & Social Psychology, 55, 1-5. to be denoted by words containing relatively few sylla­ BROWN, R., & LENNEBERG, E. H. (1954). A studyin languageandcog­ bles (Brown & Lenneberg, 1954). Thus, even though the nition. Journal of Abnormal & Social Psychology, 49, 454-462. individual correlations between syllable number and the CAREY, S. (1982). Semantic development: The state of the art. In variables of complexity, prototypicality, and grammati­ E. Wanner& L. R. Gleitman(Eds.), Language acquisition: The state cal category might be small, their joint existence may ofthe an (pp. 347-389). New York: Cambridge University Press. CAREY, S. (1986). Constraints on semantic development. In direct the attention of language learners and users toward W. Demopolous& A. Marras (Eds.), Language learning and con­ syllable number as a basis for inductions. cept acquisition (pp. 154-172). Norwood, NJ: Ablex. 536 KELLY, SPRINGER, AND KEIL

CASSIDY, K., & KELLY, M. H. (1990). Phonological bases for gram­ SWBIN,D. I. (1973). Cognitive prerequisites for the acquisition of gram­ matical category inferences. Unpublished manuscript. mar. In C. A. Ferguson & D. I. Siobin (Eds.), Studies ofchild lan­ CHOMSKY, N. (1980). Rules and representations. New York: Colum­ guage development (pp. 175-208). New York: Holt, Rinehart & bia University Press. Winston. CLARK, E. V. (1983). Meanings and concepts. In P. Mussen (Series SNODGRASS, J. G., & VANDERWORT, M. (1980). A standardized set of Ed.) and J. H. Flavell & E. M. Markman (Vol. Eds.), Handbook 260pictures: Norms for name agreement, image agreement, familiar­ of child psychology. Vol. 3: Cognitive development (pp. 787-840). ity, and visual complexity. Journal ofExperimental Psychology: Hu­ New York: Wiley. man Learning & Memory, 2, 174-215. CUTLER, A., NORRIS, D., & WILLIAMS, J. N. (1987). A note on the STEVENS, J. C., & MARKS, L. E. (1965). Cross-modality matching of role of phonological expectations in speech segmentation. Journal of brightness and loudness. Proceedings of the National Academy of Memory & Language, 26, 480-487. Sciences, 54, 407-411. FAY, D., & CUTLER, A. (1977). Malapropisms and the structure of the TUCKER, G. R., LAMBERT, W. E., RIGAULT, A., & SEGALOWITZ. N. mental lexicon. Linguistic Inquiry, 8, 505-520. (1968). A psychological investigation of French speakers' skill with GELMAN, R., & GALLISTEL, C. R. (1978). The child's understanding grammatical gender. Journal ofVerbal Learning & Verbal Behavior, of number. Cambridge, MA: Harvard University Press. 7, 312-316. GREENBERG, J. H. (1966). Language universals. The Hague: Mouton. ZIPF, G. K. (1965). Thepsycho-biology oflanguage. Cambridge, MA: KEIL, F. C. (1979). Semantic and conceptual development: An onto­ MIT Press. logical perspective. Cambridge, MA: Harvard University Press. KEIL, F. C. (1983). Semantic inferences and the acquisition of word NOTE meaning. In T. Seiler & W. Wannenmacher (Eds.), Concept develop­ ment and the development of word meaning (pp. 103-124). Berlin: 1. Some related suggestions about predictors of word complexity have Springer-Verlag. appeared in the literature. Thus, Clark (1983) states that"A more com­ KEIL, F. C., & KELLY, M. H. (1986). Theories of constraints and con­ plicated word form, for example, 'grandfather' versus 'father,' in general straints on theories. In W. Demopolous & A. Marras (Eds.), Lan­ expresses a more complicated idea" (p. 815). However, the investiga­ guage learning andconcept acquisition (pp. 173-183). Norwood, NJ: tors she cites as evidence (Greenberg, 1966; Siobin, 1973) do not pro­ Ablex. vide direct support for this claim. Siobin argues that children assume KELLY, M. H. (1986). The selection oflinguistic options. Unpublished that each conceptual component of a message will have a phonological doctoral dissertation. Cornell University. realization in the morphology of an utterance. However, Siobin does KELLY, M. H. (1988). Phonological biases in grammatical category not document the extent to which the child's assumption is always cor­ shifts. Journal of Memory & Language, 27, 343-358. rect. In fact, as evidence for his claim, he points to the fact that chil­ KUCERA, H., & FRANCIS, W. N. (1967). Computational analysis of dren sometimes phonologically mark an unmarked semantic distinction present-day American English. Providence, RI: Brown University by extending a known morpheme to the unmarked case. Greenberg (1966) Press. focuses on the distinction between marked and unmarked categories in LANDAU, B., & GLEITMAN, L. R. (1985). Language and experience. phonology, syntax, and semantics, and offers some examples to sug­ Cambridge, MA: Harvard University Press. gest that marked concepts are denoted by words with more complex MARKMAN, E. M. (1987). How children constrain the possible mean­ morphology. However, Greenberg's examples are drawn from the kin­ ings of words. In U. Neisser (Ed.), Concepts and conceptual develop­ ship category, and no attempt is made to specify the prevalence of the ment: Ecological and intellectual factors in categorization (pp. 255­ effect in other conceptual domains. (It is ironic in this regard that the 287). Cambridge, England: Cambridge University Press. English word for the general concept of not marked has a more com­ MARKS, L. E. (1982). Bright sneezes and dark coughs, loud sunlight plex morphology ["unmarked"] than does the English word for the and soft moonlight. Journal ofExperimental Psychology: Human Per­ general concept of marked [i.e., "marked"].) ception & Performance, 8, 177-193. QUINE, W. V. O. (1960). Wordandobject. Cambridge, MA: MIT Press. ROZIN, P. (1976). The evolution of intelligence and access to the cog­ nitive unconscious. In L. Sprague & A. N. Epstein (Eds.), Progress in psychobiology and physiological psychology (Vol. 6, pp. 245-280). (Manuscript received May 9, 1988; New York: Academic Press. revision accepted for publication January I, 1990.)