Understanding functional illiteracy from a policy, adult education, and cognition point of view: Towards a joint referent framework

Literacy can best be understood by distinguishing biologically primary from biologically secondary knowledge (Geary, 2007; Geary, 2008; Paas & Sweller, 2012; Sweller, Aryes, & Kalyuga, 2011). While the former consists of information that humans were specialized to adopt during evolution, including language acquisition, like literacy biologically secondary knowledge is considered a sort of cultural “expertise” for which evolution provides no corresponding specialized neural substrate (Lachmann, 2018a; Lachmann, 2018b). In other words, literacy results from ontogenesis rather than from phylogenesis, having developed only about 6,000 years ago (Carreiras et al., 2009) and still not a universal human phenomenon (Ward, 2015). This ontogenesis, however, does not imply that the “functional architecture” of the brain of illiterate and literate people is the same. For example, during the phonological processing of words and pseudowords, different neural structures (right middle frontal-frontopolar region) are activated in illiterate than in literate adults (Castro-Caldas, Petersson, Reis, Stone-Elander, & Ingvar, 1998). This implies that mastering literacy competencies affects the functional organization of brain tissue (see Huettig, Kolinsky, & Lachman, 2018, for a review).

Behavioral studies have found differences in many aspects of cognitive functioning between literate and illiterate individuals. For example, it was found that literate individuals recognize simple two-dimensional shapes using a holistic processing strategy, while they prefer analytical processing for letters. In contrast, illiterate participants showed no processing difference between letters and nonletter shapes (see Lachmann, Khera, Srinivasan, & van Leeuwen, 2012). Undoubtedly, though, illiterate and literate adults possess the same cognitive components. What distinguishes the literate population is a fully developed, automatized, literacy-specific, functional coordination of preexisting cognitive functions (Lachmann & van Leeuwen, 2014), achieved through years of intensive, routinized daily literacy training (Froyen, Bonte, van Atteveldt, & Blomert, 2009; Lachmann & van Leeuwen, 2014).

The concepts of functional literacy and functional illiteracy (FI) were developed in the second half of the 20^th century, spurred by the growing need of advancing industrial progress and in recognition of the inadequacy of compulsory basic education to provide a sufficient level of literacy skills needed for future socioeconomic development. This article discusses the various comprehensions of FI from the following perspectives: policy and adult education, large-scale literacy assessment surveys, and cognitive and neuroscientific sciences. In order to find a common reference determination of FI, this article develops a perspective toward a common minimum intersection of diverse disciplinary and practical understandings of the notion. Thus, rather than trying to resolve the issue by providing a final definition, we offer insights to further close the disciplinary gap inasmuch as it pertains to FI. Because FI is a socially and cognitively valid concept, we advocate for a more interdisciplinary synchronized definition in the future.

Adult Education, Policy and Functional Illiteracy

The conceptualization of FI and the development of modern adult basic education (ABE) and adult literacy (AL) occurred interdependently during the second half of the 20^th century (Bulajić & Despotović, 2018). Once the need for the improvement of basic literacy skills for further socioeconomic development became recognized, different ABE and AL programs began to emerge, in conjunction with large-scale national and international literacy skills assessments. A strong impetus for the development of the ABE programs and the further development of the concept of functional literacy came from the paradigm of lifelong learning as well as from national and international large-scale studies on literacy skills. These studies, widely introduced in the second half of the 20^th century, “rediscovered” the topic of illiteracy in industrialized countries (Goffinet & Damme, 1990, p. 4) and led to the need for “appropriate provision for learning arrangements in a nonconventional and innovative manner,” based on “the principles of lifelong education on the one hand and the development of suitable practices in the field of functional literacy and basic education in developed countries on the other” (Fuchs-Brüninghoff, Kreft, & Kropp, 1986, p. IX). However, after World War II there was also a reluctance and strong opposition to recognizing the full scope of the problem in industrialized countries. For example, only at the end of 1970s did the debate begin on the inadequate level of literacy skills in the population of Western Germany, though this had occurred somewhat earlier in the United Kingdom during the BBC’s National Adult Literacy Campaign (Fuchs-Brüninghoff et al., 1986). By this time, it had become apparent that the notion of illiteracy, often defined as the inability to recognize words and even identify individual letters, needed to be broadened. Moreover, it was discovered that free and compulsory elementary education was not as a strong guarantee as previously believed for the acquisition of an adequate level of literacy skills to ensure further socioeconomic development. As a result of these insights, the notion of functional literacy was born.

At the end of the 20^th century, the results of the International Literacy Survey (IALS) showed that at least 25 % of the adult population in 13 industrialized countries was not functionally literate, i.e., did not possess “the minimum level of competence needed to cope adequately with the complex demands of everyday life and work” (OECD, 1997, p. 3). This dramatic insight was followed up by the innovation and intensification of the ABE and AL programs in many industrialized countries. However, in addition to education policy and practice, large-scale assessment studies and life-long learning philosophy, functional literacy was also influenced by an increasing interest in the topic by cognitive science. The latter became highly focused on analyzing cognitive-cerebral patterns of written language processing, i.e., the perception and reproduction of a written language, and especially on comparing differences between literate and illiterate individuals in that respect.

Functional Literacy – Defining Its Conceptual Boundaries

Up until then, the concept of FI and of functional literacy had been rather resistant to attempts to be defined in a more operationalized manner. One of the main reasons for determining functional (il)literacy definitions only as a broad descriptive narrative is that functional literacy represents a dynamic concept shaped by current cultural events. Thus, the concept was primarily defined normatively, according to the needs of the respective time and the cultural context, social development, or specific demands of the labor market and further education (Bulajić & Despotović, 2018). Our understanding of the term “literacy” can thus be historically divided into the period before 1950, when literacy was understood solely as alphabetical literacy (word and letter recognition) and the period after 1950, when literacy slowly began to be considered as a wider concept and process, i.e., functional literacy (Dijanošić, 2009). Although functional (il)literacy has become one of the priorities of educational policies and scientific research in the last decades, there is still no coherent image nor sufficiently empirically based conclusions on what the cognitive profile is for a functionally illiterate person. This deficiency also includes operational definitions, estimates, and/or differential diagnostic patterns of FI (Vágvölgyi, Coldea, Dresler, Schrader, & Nuerk, 2016).

The 20^th session of UNESCO General Assembly in 1978 served as a cornerstone for further research and the implementation of intervention programs regarding FI, as functional literacy then became fully acknowledged on an international level for the first time. A functionally literate person was defined as a person “who can engage in all those activities in which literacy is required for effective functioning of his group and community and also for enabling him to continue to use reading, writing and calculation for his own and the community’s development,” while someone who is functionally illiterate was defined as the negation of the previous statement (UNESCO, 1979, Annex I, p. 18). A literate person who does not possess literacy skills at the level of appropriate functionality, i.e., an individual who is functionally illiterate, would only be able to read, write, and comprehend “a short simple statement on his everyday life” (Annex I, p. 18). Therefore, FI should be distinguished from (primary) illiteracy, which is defined as the inability to read and write a short simple statement concerning one’s own everyday life.

Based on this formal recognition of FI within UNESCO, and reflecting a transformation in the understanding of literacy as more than simple reading and writing skills, new literacy programs started to emerge. These took the form of modern and functional ABE and AL, and there was a tendency to widen the content and outcomes of the programs to address different aspects of adult life. For example, the 1991 National Literacy Act (USA) significantly expanded the scope of literacy programs that had previously treated low literacy levels in adults as a “short-term crisis that could be quickly addressed and eliminated” (Belzer, 2017, p. 12). After 1991, the US Federal Government began building the infrastructure for more long-term and wider actions leading to the evolution of traditional AL programs into more functional ABE. Considered to be more than an instrumental activity of acquiring basic literacy skills, these new programs began to be perceived as a first step in introducing wider logistical and psychological changes into the lives of often marginalized illiterate adults (Bedder & Valentine, 1990). Consequently, ABE evolved into the “symbolic activity in which student’s internalized or perhaps socially imposed feelings of inadequacy are formally deleted” (p. 79). As such, ABE was almost seen as an intervention in which a dose of modernity is to be injected into the reference frame of illiterate or uneducated people, representing a sort of modern formalized and institutionalized normative rite of passage into the world of modernity.

This broadening of the ambitions of ABE programs inevitably led to an expansion of the concept of functional literacy in adult education policy and practice. In the numerous attempts to comprehensively approach functional literacy, some of them went so far as to violate the limits of representing the phenomenon. Various skills that went beyond the literacy concept started being included in functional literacy. For instance, the Dutch law on Adult Basic Education from 1987 connects functional literacy with additional components/outcomes encompassing different social skills in addition to linguistic and numerical literacy skills. The law also defined an upper limit of previous education allowed for inclusion in ABE as completed 2nd year of high school (Hamminock, 1990). What we consider problematic for this comprehension of functional literacy is the inclusion of additional concepts of social skills in it. The law and program goals prescribed the effective use of basic skills in 14 different areas such as “education and training, education of children, work, hobby, household and environment, family life and home care, social security, social participation, communications and media, consumer culture, health care, politics and culture, transport, personal interests” (p. 16).

Although this and similar descriptive definitions emphasize the importance of different contexts and individual and social development, we believe that they do not represent functional literacy, but rather a considerably wider concept. Such a “holistic” approach is not helpful for conducting empirical research or for creating specific instruments for FI assessment. Ultimately, it forces researchers to create their own definitions of FI in a broad manner. Thus, not uncommonly in adult education literature, one finds a high number of similar reflections on functional (il)literacy, for instance: “Literacy is much more than reading and writing; it is a way of communication, the acquisition of knowledge, the learning of language, the development of culture” (Dijanošić, 2009, p. 28). Similarly, many other European authors consider functional literacy in the 21^st century not to be only a set of basic skills, but rather a complex corpus of knowledge and skills, the strategy of personal development in the context of lifelong learning, as well as the basis for the development of an integrated and educated European community (see Mukan & Fuchyla, 2016). Moreover, these broad definitions emerging from adult education seem to equate functional literacy with the wider concept of lifelong learning competences, such are those defined in the European reference framework for such key competences (European Parliament and the Council of Europe, 2006).

Functional Illiteracy and Primary Illiteracy, Cognitive and Neuroscientific Research

So far, most studies on the cognitive and brain aspects of illiteracy have dealt with primary illiteracy or full illiteracy. Possessing absolutely no reading and writing skills in any language, possibly because of not having received any organized and systematic literacy training, may be referred to as primary illiteracy (Boltzmann, Rüsseler, Ye, & Münte, 2013). Some inferences relevant for FI can be drawn from studies conducted on individuals who are primary illiterates, which showed that illiterate adults achieve poor scores on a wide range of cognitive abilities tests, especially those concerned with reading-related cognitive domains and tasks such as verbal fluency, verbal memory, visual and numerical abilities (Ardila, Ostrosky-Solis, & Mendoza, 2000). The exception was the naming and identification of real objects or orientation ability (see Ardila & Rosselli, 2007). It was found that education level explains variance in cognitive skills much better than age. For example, in the domain of verbal abilities, there is no decline as the function of age, when differences in the educational level are controlled for (Albert & Heaton, 1988). Similar inferences apply to FI individuals as well. They also achieve low scores on the wide spectrum of cognitive tasks, including those targeting skills unrelated to reading and writing specifically, such as visual organization, mental spatial orientation, vigilance, divided attention, visual memory, and visual organization (van Linden & Cremers, 2008).

Several studies and meta-analyses (Petersson, Reis, Èf, et al., 2000; Petersson, Reis, & Ingvar, 2001; Petersson & Reis, 2006; Reis & Castro-Caldas, 1997; Reis, Petersson, Castro-Caldas, & Ingvar, 2001; Rosselli, 1993) provide a more general overview of the effects of education, i.e., literacy skill mastering on cognitive abilities:

• a)
  Functional and anatomical cortical and neural differences between literate and illiterate individuals
• b)
  General cognitive functioning
• c)
  Cognitive abilities associated with natural language (verbal fluency, semantic and phonological coding of visual representations, phonological awareness, capacity of verbal working memory)
• d)
  Numerical abilities (counting, number processing, basic calculus, and estimation of quantity)
• e)
  Visual and spatial abilities (visual reproduction of simple two-dimensional objects, identification of objects in superposition, e.g., modified, extended, masked objects, and other abilities)
• f)
  Different domains of memory

When it comes to language processing and literacy, many studies (e.g., Reis & Castro-Caldas, 1997) showed that illiterate individuals are limited to a semantic system of oral-language processing, while literate persons use all three pathways (lexical, semantic, phonological) in a general strategy for solving language-related tasks. Mastering literacy skills seems to create new and qualitatively different strategies of oral-language processing, e.g., “conscious phonological processing, visual formal lexical representation, and all the associations that these strategies allow” (p. 445). Other studies (Kosmidis, Tsapkini, Folia, Vlahou, & Kiosseoglou, 2004) confirmed that there is no qualitative difference in semantic processing strategies between literate and illiterate individuals, only quantitative ones, such that education (i.e., literacy training) enhances the effectiveness of semantic processing strategies. However, literacy does indeed affect phonological aspects of language processing (phonological awareness, phoneme-grapheme correspondence) in a qualitative manner. This was confirmed by neuroscientific studies that showed a lower ability of illiterate persons to separately process phonological aspects of the language. Hence, although they can rhyme or manipulate syllables, they lack the ability to add/remove consonants from word beginnings, memorize phonologically related pairs of words, and repeat pseudowords. Regarding the final skill/task, individuals who are illiterate tend to make the specific mistake of transforming pseudowords into meaningful concepts (Landgraf et al., 2012; Reis & Castro-Caldas, 1997). In pseudowords repetition, noticeable differences occur that are related to the phonological loop, i.e., interactions between the Broca’s area and the inferior parietal region. Differences were also found regarding the posterior-midinsular bridge between Wernicke’s and Broca’s area (Petersson, Reis, Askelöf, Castro-Caldas, & Ingvar, 2000, p. 364). Furthermore, the fact that differences in phonological processing are culturally universal was also shown by a silent word and picture-naming task study in literate and illiterate Chinese adults (Li et al., 2006) which concluded that literacy strongly influences patterns of neuronal activity leading to “increased efficiency of cognitive processing of tasks related with the language” (p. 144).

Besides the aforementioned phonological differences, important disparities in neural functioning also appear to underlie orthographical processing related to different illiteracy levels. The left ventral occipito-temporal cortex, called the “visual word form area” (VWFA; Dehaene, Poline, Le Clec’H, Le Bihan, & Cohen, 2002) is found to be closely related to reading acquisition. It seems that, as the reading skill is being mastered, the responsivity of the region starts shifting more toward script rather than to nonletter objects. After reading acquisition, the VWFA is still responsive to nonscript visual stimuli, though it responds more actively to script than other visual objects. ERP data showed that the left-lateralized, VWFA-associated N170 component is greatly enhanced in individuals who are literate and formerly illiterate compared to illiterate ones, following visual presentation of a letter string (Dehaene, Cohen, Morais, & Kolinsky, 2015, p. 2).

These findings may serve as valid markers of neural differences, not only between illiterate and literate individuals, but also between different levels of illiteracy, such as between individuals who are primary illiterate and those who are functionally illiterate. Several studies conducted with individuals who had completed 9 months of intensive literacy training for functionally illiterate adults in Germany (Alpha Plus) and various controls (functionally illiterate individuals who had attended less intensive literacy training and average readers) provided several new insights. In response to word presentation, there was an increase in the VWFA related N170 amplitude observed in formerly functionally illiterate individuals after completion of intensive Alpha Plus training, compared to before the training, whereas no differences were found in controls (Boltzmann & Rüsseler, 2013). A parallel fMRI study showed differences in activation of the fusiform gyrus, often regarded as a key neuronal component of word recognition (Boltzmann et al., 2013). There was larger activity found in fusiform gyrus (including VWFA) in formerly functionally illiterate adults immediately after the training completion compared to pretraining baseline. While some benefit can almost always be related to various ABE/AL programs, both studies provide strong evidence that only intensive interventions yield efficient (functional) reading skills. The above-mentioned studies validate the benefits of literacy training intervention in several different ways. They show that there is (1) a diminution/disappearance of the neural functional differences between literate and formerly functional illiterate individuals after training intervention, (2) a positive correlation between the N170 enhancement and reading skills before and after training, and (3) that N170 can be modulated even in adulthood.

It seems that FI adults have linguistic deficits in numerous domains such as phonological, orthographic and lexical processing, oral and reading comprehension, and verbal fluency (Vágvölgyi et al., 2016). Apart from the neural differences mentioned, the use of oral language in illiterate adults is also observed to be characterized by lower fluency, simpler grammar, and lower symbolic representability of language i.e., greater attachment to a concrete and direct context, or more action-obvious direction of verbal reasoning (see Ardila et al., 2010). A recent study on the impact of years of schooling on a range of language skills and abilities showed differences in the variation of the following abilities and skills in relation to the time spent in the education: oral-language comprehension, reading, graphical comprehension, naming, lexical availability, dictation, graphical naming of actions, and number reading (Soares & Ortiz, 2009).

The above-mentioned studies show that education and literacy training primarily affect the coherence and development of semantic (quantitative differences), phonological, and syntactic processing. The nature of the stimulus used in cognitive tasks also appears to affect performance differences between literate and illiterate individuals. For example, it was shown that literate and illiterate adults showed no difference in naming usual everyday real objects, whereas there differences did appear if the stimuli were photographs or drawings of given objects (Reis, Guerreiro, & Castro-Caldas, 1994; Reis et al., 2001). Thus, it was found that the further the stimulus is from concrete objects, the greater the performance differences. Hence, as in many other examples, the ability of illiterate individuals decreases with the level of abstraction of the task on the continuum of concrete-iconic-symbolic. This applies for visual-orthographic as well as semantic aspects. Reis et al. (2001) pointed out that literacy strongly influences the visual system or mediates the relationship between the visual and the language system. This general conclusion agrees with the behavioral research on differences between literate and illiterate persons’ recognition of letters and simple two-dimensional shapes. It suggests that, unlike literate persons, illiterate ones visually perceive letters (perceptive strategy) similarly to how they perceive two-dimensional shapes (Lachmann et al., 2012).

Large-Scale Literacy Surveys and the Concept of Functional Illiteracy

Large-scale international adult literacy surveys have traditionally been carried out by global international organizations such as the OECD and UNESCO. The most commonly known ones were carried out by the OECD, such as the International Adult Literacy Survey (IALS) administered between 1994 and 1998, the Adult Literacy and Life Skills Survey (ALL) applied between 2003 and 2007 (OECD, 2000), and their successor, the Survey of Adult Skills a product of PIAAC (The Programme for the International Assessment of Adult Competencies). The latter has been in place since 2012 to the present day (OECD, 2013a; OECD, 2013b; OECD, 2016). It may be important to also mention the UNESCO’s Education for All (EFA) global program, launched in 2000 by the Dakar Framework for Action initiatives (UNESCO, 2000), which relies on national reports to evaluate and monitor the progress of member states toward the defined program goals. One of the goals was to reduce the illiteracy of adults by 50 % by 2015, which, unfortunately, has not been achieved. Starting from the estimate that in 2000 about 18 % of all adults in the world were illiterate, the situation in 2015 reveals that 14 % of the adults in the world population were illiterate. Two major national literacy skills surveys are also well-known: the National Assessment of Adult Literacy (Baer, Kutner, Sabatini, & White, 2009) in the United States and the German Level One Study (leo.; Grotlüschen, Riekmann, & Buddeberg, 2015; Grotlüschen & Buddeberg, 2017). In addition to these, there are also several standardized and commercially available literacy tests presently in use for literacy assessment, mainly in English, such as a specially designed ABE learning impact assessment tests (e.g., Test of Adult Basic Education, consisting of subtests of reading, mathematical skills, language skills, vocabulary, and spelling at five levels of difficulty; CTB/McGraw-Hill, 2008).

For the further operationalization of FI and an understanding of which skills and what levels it encompasses, it would be beneficial to define FI within the leo. and PIAAC scale levels, which would help to bridge different FI comprehensions, including those of policy and adult education on the one hand and cognition on the other, as these studies are constituted by both.

Functional Illiteracy and the Development of Reading Skills

The behaviorally manifested differentia specifica of FI compared to primary illiteracy means having a fair ability in letter and word recognition and comprehension as well as comprehension of single sentences. The FI-specific feature compared to full literacy is a low effectiveness in text comprehension. This may then beg the question of what the status of the cognitive components and processes underlying FI individuals’ reading skill would be. We expound on this in the following paragraphs.

From the criteria given above, we presume that FI implies having completed processes for the development of phonological awareness. Yet, there are studies that claim literacy in general is not required for solid phonological awareness, but rather one’s knowledge of the alphabet that distinguishes or at least largely contributes to good phonological awareness skills (Falk Huettig, Lachmann, Reis, & Petersson, 2018; Read, Yun-Fei, Hong-Yin, & Bao-Qing, 1986). However, because FI is a broad category, FI adults may share some of the same difficulties as illiterates with respect to phonological awareness. These include issues concerning onset (but not rhyme) phonological awareness as well distinguishing phonologically similar words (Landgraf et al., 2012).

We may also presume the existence of the developed phoneme-to-grapheme conversion relative to level of orthographical depth/transparency of the language in FI individuals. Because FI requires the recognition and comprehension of words, one may expect to find the word superiority effect (Cattell, 1886; Reicher, 1969; Wheeler, 1970) in FI individuals. Thus, both routes, the alphabetic and the lexical semantic route (Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001), should be developed to some extent. Deficiencies in FI individuals relative to literate persons may also be expected in terms of richness of mental lexicon (stemming from less frequent exposure of prose texts), in addition to difficulties operating with words of increased level of abstractness and related verbal-logical aspects of language and text (Bulajić & Despotović, 2018). A lower capacity not only of verbal, but also of visual short-term and working memory is also well established (van Linden & Cremers, 2008). Lower scores on verbal intelligence tests are also likely to be expected as a consequence of all the aforementioned verbal deficiencies in association with other additional causes.

In a more general outlook on reading and FI, we refer to the functional coordination framework, which describes the cognitive processes involved in reading (Lachmann & van Leeuwen, 2014; Lachmann, 2018b). The framework contains four stages: recruitment, modification, coordination, and automatization. When learning to read, the individual first reverts to already existing components and skills, that is, primarily auditory and visual ones. These skills are then modified to be optimized for the reading context. Stated in Piagetian terms, the existing visual-auditory perception schemes accommodate and broaden up to enable the assimilation of the written material. During the third stage, phonological skills (grapheme-to-phoneme conversion) and analytical strategies for letter perception (Lachmann et al., 2012) achieved in the second stage are coordinated. This coordination is automatized (Nicolson & Fawcett, 2018) over several years during the final stage (Froyen et al., 2009).

Based on the framework of the model, we can hypothesize that FI adults did not fully achieve complete coordination of the processes from the modification phase and, most importantly, did not properly or fully automatize the whole process. This can be inferred based on their ability to read individual words and sentences, yet their lack of capacity to understand longer text in its entirety. Indeed, our main hypothesis is that FI adults perform with low effectiveness and efficiency at the text level because they invest more cognitive load to reading individual words and sentences due to a lack of automatized reading. Consequently, they have less residual cognitive capacity for comprehension on the test level. Alternatively, the reading process in some FI individuals may be automatized, but the modification or coordination of skills underlying reading is inadequately developed.

Toward a Definition of Functional Illiteracy

Recently, Vágvölgyi et al. (2016) suggested an operational definition of FI as “the incapability to understand complex texts despite adequate schooling, age, language skills, elementary reading skills, and IQ. These inabilities must also not be fully explained by sensory, domain-general cognitive, neurological or psychiatric deficits” (p. 9). In addition, the authors offer inclusion criteria for FI such as older than 16 years of age, minimum of 6-8 years of schooling, native-like oral language skills, as well as exclusion criteria for “pure FI”: IQ below 70, neurological or mental disorder, uncorrected speech, hearing, or vision problems, dyslexia, dyscalculia, and hyperactivity.

Based on this definition and in light of the aspects we discussed earlier in this article, we recommend the following criteria for a future operational definition of FI:

Conclusion

Literacy acquisition is a long-term process of conceptual and procedural learning that must combine many preexisting cognitive functions to attain full proficiency. As a cultural imperative, literacy has been increasingly imposed on individual cognitive systems since the establishment of compulsory basic education. In the process of mastering literacy, individuals go through several stages of an intensive learning process, starting with gaining conceptual knowledge about letters and then the manner in which words are composed, which in turn form sentences and texts. This is followed by the acquisition of a procedural knowledge of automatizing the cultural practices of reading and writing on, more or less, an everyday basis. The assimilation of this behavioral aspect forces an individual to accommodate and reorganize cognitive structures in order to create/incorporate the novel system underlying written language. Stated differently, existing cognitive and neuronal systems supporting biologically primary knowledge become “recycled” (neuronal recycling hypothesis; Dehaene, 2005); the old functions are weakened in order to respecialize the processing of secondary knowledge such as reading (e.g., literacy-induced changes in left VOT region). According to an alternative explanation, these preexisting cognitive systems are not recycled per se, but rather “synthesised in a novel manner” (Lachmann & van Leeuwen, 2014): They preserve their original functions, but become reorganized and recoordinated on a new, higher level by building up an automatized higher order system for supporting evolutionary novel behavior, i.e., literacy.

In this paper, we offered a perspective and several recommendations for criteria to develop a more operationalized definition of FI, to serve as a basis for future multidisciplinary utilization. We argued that there are four different approaches to FI, that highlight different aspects of what functionality is in the notion of functional (il)literacy, as they all tend to explain different categorical levels of functionality. However, these all reference the same unitary but complex skill of literacy. From the perspective of policy and ABE, functionality refers to a literacy level sufficient for integration in a (post)modern industrial society as well as for personal well-being and lifelong learning, communal and economic development (social inclusion/development level). Large-scale literacy studies understand functionality to be a level of efficient and fluent reading/writing, sufficient for manipulating and understanding prose and document texts that are ecologically important for everyday functioning (behavioral level). The cognitive science approach emphasizes functionality pertaining to established and developed cognitive processes underlying reading skill, such as phonological awareness, orthographical processing, and lexical route-based reading strategy (cognitive level). The neuroscientific approach focuses on functionality in terms of accommodation, recycling, and/or reorganization of neural structures that emerge along with literacy learning and that, in return, enable literacy on an average reading level (neural level). The future operational definition of functional (il)literacy should incorporate all four aspects in a more coherent and cohesive manner. In the current areas of research, a vast plurality of definitions is utilized, making these studies often mutually incomparable. In order to accomplish a more multidisciplinary synchronized approach, it is necessary that each of the approaches outlined further explore and explain what defines the functionality threshold in each of the four categories/domains in a mutually aligned manner. The possible outcome of this endeavor would answer the important questions implied at the beginning of the text, such as: What is the cause of functional illiteracy that distinguishes it from primary literacy or learning difficulties such as dyslexia? Also, what is the cognitive profile of an individual whose literacy is (not) functional enough to allow that person to participate in a (post)modern society without encountering reading/writing-related obstacles? In closing, we would make a suggestion that, as the research field(s) of functional illiteracy consider FI to be literacy that is underdeveloped, inefficient or not functional enough, a more precise term that may be used to describe the phenomenon is “dysfunctional literacy”.