Modeling Multilayered Complexity in Literary Texts (2025)

Abstract: We explore the relationship between stylistic and sentimental complexity in literary texts, analyzing how they interact and affect overall complexity. Using a dataset of over 9,000 English novels (19th-20th century), we find that complexity at the stylistic/syntactic and sentiment levels tend to show a linear association. Finally, using dedicated datasets, we show that both stylistic/syntactic features – particularly those relating to information density – as well as sentiment features are related to text difficulty rank as well as average processing time.

## introduction literary texts exemplify language operating at its most refined and demanding: they are capable of generating an experience -often emotional or evocative @xcite -through the sheer force of words @xcite @xcite . in this domain, language's capacity to evoke emotions, construct worlds, and create experiences is pushed to its limits. to do so, literary texts explore the boundaries of what human language can achieve in terms of expressiveness, depth, and evocative power. it manipulates form and meaning for its effects in a way that seems unmatched in other domains -exhibiting complexity at multiple levels, for example, matching an information-dense style with an unpredictable narrative. multidimensional complexity might also be the reason why traditional stylistic metrics for gauging the difficulty of a text -often developed for nonfiction -such as readability formulae, do not adequately capture the level of complexity of literary texts @xcite ; and might be a factor in why literary texts are associated with longer human processing times than nonfiction @xcite . this complexity, however, might not manifest uniformly at all levels: a literary story may be emotionally complex while maintaining a simplified syntax. this is why the problem of modeling complexity at different linguistic levels in literary language presents a particularly intriguing challenge. understanding how linguistic complexity affects reader experience and whether there are trade-offs between formal and emotional aspects is critical in unraveling the cognitive demands and rewards associated with literary reading. while many recent studies have sought to gauge the effect of stylistic and syntactic features of complexity for forms of reader appreciation @xcite @xcite @xcite , the sentiment and emotional dimension has been an overlooked aspect of literary complexity. complexity at this level is difficult to define. while a metric like simple sentiment standard deviation can be used to gauge the width of the 'sentiment palette' that authors are using in a novel, some more sophisticated measures for the complexity of novels' sentiment arcs -i.e., the trajectory of positive and negative valences across a story -have been developed in recent years, like the approximate entropy or the hurst exponent of sentiment arcs @xcite . very little work has explored the connection between these different levels of complexity: the relation between complexity at the stylistic level and complexity at the sentiment level. moreover, little work has tested whether sentiment complexity behaves similar to stylistic and syntactic complexity in relation to reader experience. to address this gap, we pose two research questions. firstly: rq1: what is the relationship between complexity features at different textual levels (e.g., stylistic/syntactic, and sentiment levels)? we hypothesize two possible relationships between different levels of complexity: h1a: there is a trade-off between complexity at different levels, where, e.g., increased stylistic and syntactic complexity leads to "simplification" at the sentiment level. h1b: complexity features at different levels cooccur, so that, e.g., higher stylistic and syntactic complexity is associated with greater sentiment complexity. 2 the first two hypotheses carry different consequences. the first hypothesis (h1a) draws from the concept of 'cognitive compensation' observed in other domains, which suggests that optimized communication requires distributing readers' cognitive load across linguistic layers. for example, when lexical complexity increases, syntactic structures may simplify to balance cognitive demands @xcite . in this scenario, complexity at one level could functionally balance complexity at another -for instance, syntactic complexity might work alongside sentimental simplicity. in contrast, h1b derives from the idea that aesthetic phenomena function as 'supernormal stimuli', intentionally amplifying complexity across levels to heighten engagement, eliciting amplified responses @xcite . this scenario also carries the interesting possibility that works with high stylistic and syntactic complexity also embrace challenging sentiment profiles. heightened complexity at multiple levels would impose a higher cognitive load on readers, yet could foster a more compelling aesthetic experience. secondly, we seek to probe the relation of each feature level to actual reader experience: rq2: what is the relationship between complexity features at different levels of a text and cognitive load experienced by readers? h2a: features at the sentiment level behave like stylistic and syntactic features in increasing readers' cognitive load, impacting the reader's ability to process the text. h2b: features at the sentiment level have an in-verse behavior to stylistic and syntactic features, so more complexity at the sentiment level decreases readers' cognitive load. 3 through these questions, we aim to explore how complexity at different linguistic levels might enhance or compromise one another. in a first part of this study, we investigate the relationship between stylistic/syntactic and sentiment complexity (rq1) in a large corpus of novels. in the second part, we assess whether sentiment complexity mirrors stylistic/syntactic complexity in its impact on readers' cognitive load (rq2), using dedicated datasets on reading time and novels' difficulty rank. much of the focus on stylistic and syntactic complexity can be traced to formalist literary theory, which emphasizes stylistic discomfort as a hallmark of the literariness of texts. this theory argues that literary texts slow down reading by creating linguistic unfamiliarity or "foregrounding" @xcite ). while some work has found reader consensus on foregrounding phenomena @xcite , no comprehensive taxonomy of such features exists. still, such features have been implicitly assumed to be formal or stylistic. this aligns with a long-standing debate on formalism in literary analysis, where a superficial focus on form has been claimed to overshadow content @xcite . as an exception, the experimental study of @xcite found that reading times increased with the frequency of foregrounding features, including affective features in their taxonomy. other, more theoretical studies have suggested that the extended processing time associated with literary texts @xcite is linked to emotional and emphatic engagement @xcite and to increased reflection on non-literal meaning distinctive to literary reading @xcite . in short, the complexity of literary texts may evoke more cognitively demanding affective processes than nonfiction, echoing the idea of literary texts as enhanced stimulus objects @xcite . moreover, recent psycholinguistic research has also emphasized how sentiment and emotional engagement affect readers' cognitive load, showing that negative valence and emotional features can increase reading times and that readers respond rapidly to valence cues @xcite @xcite . these studies suggest that sentiment plays a critical role in reader experience, yet few works have explored the intersection of stylistic, syntactic, and complexity at the sentiment level. while sentiment analysis (sa) has become a popular method for gauging emotional content in texts @xcite , its application in literary analysis remains conceptually and theoretically underdeveloped. some recent work has applied complexity measures such as approximate entropy and the hurst exponent to sentiment arcs, suggesting that these measures provide insight into the complexity of narratives at the level of feelings or emotions evoked @xcite . yet, the connection between complexity at the stylistic level and the complexity in sentiment trajectories measured by these metrics remains largely unexplored. we seek to fill this gap by investigating the relationship between stylistic/syntactic complexity and complexity at the sentiment level in literary texts, contributing to the broader understanding of how complexity at different linguistic levels interacts to shape the complexity profile of literature and its readers' cognitive experience. ## conclusion our results pertaining to our first question (rq1) support h1a. rather than a balance between different aspects of language, we find that, at least over the whole chicago corpus, complexity at the stylistic and syntactic level tends to correspond to complexity at the sentimental level. regarding our second question (rq2), our findings support h2a: it seems that both the stylistic/syntactic and the sentimental complexity impact the cognitive load of the readers, not only when measuring whole novels but even within much shorter stories. we should thus assume that the novels that push both levels to higher complexity are indeed asking more from the readers, and are providing a more challenging experience. it's not obvious that features like overall variance in sentiment (sentiment sd) and the local and global linear dynamics of the sentiment arc (apen, hurst) would relate to perceived complexity, making this finding particularly intriguing. the question then remains as to why these two levels of complexity are tendentially intensified together, rather than showing a trade-off. in other words, why do works that offer a wider sentimental palette or a less predictable story arc also have, in general, a higher noun-to-verb ratio and a wider vocabulary? such literature -complex on multiple levelsmay offer higher-quality reading experiences by amplifying both emotional and stylistic profiles. in this way, our findings suggest that literature may function as a "supernatural stimulus", where every element is intensified simultaneously -a phenomenon that, while possibly engaging in fiction, would be counterproductive in nonfiction or more didactic texts, where clarity and ease are often prioritized. this distinction potentially sets literary texts apart from other domains, though future studies should more rigorously test differences between literary and nonliterary texts with regard to multidimensional complexity. the possibility of a trade-off between these dimensions of language is not off the table: it might occur within specific groups of texts with varying degrees of difficulty; and it is also possible that specific works of literature strike a balance differently, depending on their intended audience and the author's specific style. but in general, our findings suggest that rather than being independent dimensions, style and "content" -taking sentiment here as a semantic element -might have a strong relation in literary texts. the style of the texts might have to align with its semantics, at least at the sentimental level. in this sense, the relevance of linguistic traits associated with the "nominal style" is particularly intriguing. @xcite has shown that this style is developed and applied in scientific and technical language to convey semantic information more efficiently while requiring a higher degree of concentration and preparation from the reader. this "optimal" strategy of linguistic communication might not be limited to technical prose but be exploited, despite their completely different aims, by literary works as well. in other words, it is possible that some aspects of complexity at the stylistic level are necessary for most works of art to convey the complexity of the sentimental level in a manner that is most effective to the creation of a powerful reading experience. in the future, we intend to explore the relationship between these levels of complexity in literary language further, better formalizing the relation and role of each of the selected components. we would also examine the relationship between the perceived complexity or difficulty of a text and these features in an experiment setting.