Abstract
Repetitive behaviours occur in children with vision impairment and those on the autism spectrum. However, there is negligible research focus on the similarities and differences between these two groups of children. This narrative review explores literature in the fields of vision impairment and autism to understand how repetitive behaviours are defined, explained, and supported in the respective fields. This comparative analysis highlights that while experiences of stigma are same for family members of both groups of children, there are some differences in terms of conceptualisation of repetitive behaviours and what is considered as underlying cause for these behaviours.
Keywords
Introduction
Repetitive behaviours (RBs) are common in children with vision impairment (VI) and children with autism spectrum disorders (ASDs). However, comparative studies on RB in children with both these conditions cannot be found. While studies exist separately for RBs in VI and in the ASD, these mainly focus on the definition of RB (Donvan & Zucker, 2016; Whitehouse & Lewis, 2015), its description (Lam & Aman, 2007; Pinquart & Pfeiffer, 2012), and the reasons for which it is being displayed (Boucher, 2017; Gal, 2006; Gena, 2002; Leekam et al., 2011; Li, 2009). In the field of VI, negative impacts of RB (Smith et al., 1969; Stone, 1997; Warren, 1994; Webster & Roe, 1998) on the child and the social environment along with the measures that have to be taken to eliminate it (Brame et al., 1998; Moss et al., 2009) have been indicated. Similarly, conclusions are also drawn in the case of ASD (Rojahn et al., 2016; Sethi et al., 2019) and research focusing on intervention decisions (Amaral et al., 2011; Sethi et al., 2019; Wolfe et al., 2014).
While similar areas have been explored with regard to both conditions, what is missing is a comparison to understand how similar or different these experiences are. This is surprising considering that ASD has been mentioned as occurring condition in some of the VI literature (Mukaddes et al., 2007). This article attempts to provide a comparative narrative literature review of studies conducted in the fields of ASD and VI with an aim as follows:
To understand how RBs are defined and understood in individuals with VI and those with ASD;
and what can be learnt by comparing this literature in terms of the construction of these disabilities, researcher priorities, and the experiences of those with the condition and people around them.
This literature review was part of a study that explored the perceptions of parents of children with VI and ASD living in Greece, and professionals working with these children. We used the Ecological Systems Theory (Bronfenbrenner, 2001; Bronfenbrenner & Morris, 2007) to understand the development of perceptions and their impact on children with disabilities and their families.
Method
Search strategy
Literature was sourced via online databases, academic libraries, and physical libraries in the United Kingdom and in Greece. The databases used were Sci-Hub, EthOS, European E-Theses, ProQuest Dissertations, ProQuest, ERIC, ScienceDirect, PubMed, and the Serbian KoBSON. Apart from the databases, a manual online search using Google Scholar and the University’s library search engine was also undertaken. In addition, various local and national libraries, and specialist charity libraries were visited. This physical search was carried out to be sure that any sources in the course of an online pursuit were not missed.
The following keywords were used for the search: ‘repetitive behaviour’, ‘repetitive movement’, ‘ritual behaviour’, ‘stereotypy’, ‘mannerism’, ‘challenging behaviour’, ‘attitudes’, ‘perceptions’, ‘impact’ along with the key terms that follow: ‘vision impairment’, ‘visual impairment’, ‘sight loss’, ‘blindness’, ‘autism’, ‘autism spectrum disorder’, ‘autistic’. We also searched for related theoretical frameworks (i.e., ‘Ecological Systems Theory’, ‘Ecological Systems Theory and disability’).
Inclusion and exclusion criteria
The inclusion criteria were, first and foremost, the relevance of the content of each book or academic paper, and whether it was focused on RBs or on drawing comparisons between ASD and VI. Furthermore, the context in which a research study was conducted, or a book was written, specifically in Greece, was another key aspect of choosing that literature. We included any literature that met these criteria and published before June 2022.
Moreover, we included grey literature, which can not only be a personal experience (such as biographies, autobiographies, or memoirs) but could also be, for example, practice records. The way grey literature was selected, was based entirely on whether the author made reference to key terms, such as RB or similar, perceptions about RB and disability, impact of RB, or explanation of RB. Providing the viewpoint of individuals with VI or those on the autism spectrum (AS) crystallises the importance of the individual voice.
Data analysis
Thematic analysis (Braun & larke, 2014) was used to interpret the selected literature. To address the research aims, the results are presented under four key themes – definition of RBs, their causes, impact of RBs, and the strategies suggested to support children with RBs.
Definition and description of RB
The RBs of children with VI encompass various movements, from whole-body actions, such as whirling and running on toes, to specific gestures, such as flapping arms, and fine-detail behaviours, such as eye poking (Boyce & ammond, 1996; Brambring & Tröster, 1992; Dumont & Markovits, 1982; Gal & Dyck, 2009; Hobson, 2005; Kingsley, 1997; Pinquart & Pfeiffer, 2012; Stone, 1997; Webster & Roe, 1998). Dale and Salt (2008) suggest that RBs may emerge in the early developmental stages, starting from birth, with an increase observed up to the second year and a subsequent decrease by around 5 years of age. Brambring and Tröster (1992) note a general decline in RBs as individuals grow, except for specific behaviours, such as pressing the eyes and swaying, which remain consistent from ages 1 to 6 years.
Children on the AS exhibit a range of similar behaviours, classified into two categories: repetitive sensory-motor stereotypies and insistence on sameness. These are part of the diagnostic criteria for autism in Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) and International Classification of Diseases 11th Revision (ICD-11). The DSM-V also includes repetitive use of objects or repeating words/phrases (echolalia) as RBs in children on the AS. Ritual behaviours, proposed as a subgroup of complex RBs, are prevalent in the literature, characterised by high-level (rituals, rigid routines, circumscribed interests, resistance to change) and low-level (repetitive motor actions) behaviours (Carcani-Rathwell et al., 2006; Turner, 1996; Whitman, 2004). Classifying these behaviours remains contentious, with debates on their purposefulness (Hsu & Ho, 2009; Loh et al., 2007).
Causes for RB in VI
Apart from concerns relating to the definition and description of RB, many researchers have pointed out hypotheses regarding the reason children with VI or with ASD exhibit RB.
With regard to VI, environmental and biological causes have been proposed as contributors to the persistence of the RBs, such as sensory deprivation, restricted locomotion, social deprivation, inadequate primary caregiver–child relationships, photophobia, limited motor/ physical activity, lack of ability to imitate, and lack of variety of activities (Gense & Gense, 1994). Thus, it seems that interaction with the environment can be a source of challenge for the child with VI either due to hyperstimulation or hypostimulation (Charman & tone, 2008; Stone, 1997). RBs may help over- or understimulated children to maintain an optimal or homeostatic state of stimulation (Gal, 2006; Miller, 2005), if they have difficulty in regulating their responses to sensory input from either the body or the environment (Miller et al., 2007). This is called ‘sensory processing’ and has been mentioned by several researchers (Gal et al., 2010; Miller, 2005; Miller & Lane, 2000).
Other factors that contribute to the persistence of RBs according to researchers (Abang, 1988; Bak, 1999; Tröster et al., 1991; Warren, 1994) are an indication of boredom, constraint, communication difficulties, and overwhelming social demands. RBs could increase with anxiety and with stressful situations as well.
It is also suggested by Cass et al. (1994) and Gal and Dyck (2009) that severity of VI could affect the intensity of an RB. They argue that when the degree of VI increases, children are more likely to obtain visual stimulation through movements of their hands or fingers directly in front of their eyes or by moving their heads in front of a source of light. It is thus seen as an expression of hyperkinetic behaviour on behalf of children with low vision. Others such as Webster and Roe (1998), Banda et al. (2014), De Vaan et al. (2013), Gense and Gense (1994), Li (2009), and McHugh and Lieberman (2003) suggest that it is possible that younger children with congenital blindness or with multiple disabilities exhibit RB as a self-stimulating activity, in cases when they cannot cope with an overstimulating environment.
Causation of RB in ASD
Similarly, in the case of autism, research focused on the proximal cause or triggers for a child with ASD presenting an RB. Behavioural reasons (stress, anxiety, unpredictability, pain), environmental factors in tandem with genetic – neurobiological factors (sensory overwhelming in certain environments), cognitive barriers (communication issues, interference with educational achievement, attention, learning difficulty), or social situations (crowds, maintaining meaningful interpersonal relationships) could be the reasons for a child with ASD to manifest an RB (Charman et al., 1997; Leekam et al., 2011; Rogers, 1998; Sigman & Capps, 1997).
An additional cause might be difficulties in understanding language where it is possible that the child does not understand what the other people around them are trying to say, hence causing them to resort to an RB. Whenever this happens it is because the child experiences high levels of stress, anxiety, and aggravation (Boucher, 2017). Barton (2012), a mother of a boy on the AS quotes the words of her child who says that ‘they are obsessions that use (. . .) repetition to manage a chaotic world (. . .) to filter sensation and block out frightening or unmanageable sensory input’ (p. 231).
In addition, there is an indication of difficulty in the process of thinking, which might affect the behaviour of a child on the AS. Gena (2002) argues that children with ASD engage in activities, which can be categorised by ‘absence’ or the ‘redundancy’ of behaviour (p. 28). Redundancy of behaviour refers to RB in situations, involving visual stimuli, speech, olfactory, taste, touch, motion, and daily routines (Gena, 2002). This seems to be an area of difficulty for children with ASD, who experience senses as fragmented; thus, they plan and implement their thinking and behaviour in a fragmented way too (U. Frith, 2008).
Comparisons with autism
Jure et al. (2016) and Molinaro et al. (2020) consider that Keeler (1956) was the first to mention the link between VI and ASD, claiming that children with VI present RB just like children with ASD. In the 60s–70s, Burlingham (1965), Nagera and Colonna (1965), and Wills (1979) relate that similarity with the fact that lack of vision produces difficulties in personal development and social interaction, just like the behavioural elements observed in children with ASD. Later on, Fraiberg (1977) and Fraiberg and Adelson (1973) hold that lack of vision impacts on the self-image and self-representation of a child with VI, and thus has consequences on the ego that are externalised in the form of RBs.
On the contrary, Pérez-Pereira and Conti-Ramsden (2005) assert that children with VI do not have ‘autistic features’ (p. 99). They argue that their difficulties are related to the peripheral nervous system rather than the central, and as a consequence, they need more time to develop certain capacities, such as the Theory of Mind (Baron-Cohen, 1991; C. Frith & Frith, 2005; Hobson, 1991) and shared attention mechanism (Boothby et al., 2014; Eskenazi et al., 2013; Shteynberg, 2015).
This relation to developmental aspects was made by Dale and Salt (2008) also who observed that some children with VI show ‘autistic-like behaviours’ due to ‘unusual early social and linguistic behaviours’ (p. 136). This could be because vision drives the integration of input from other senses (Oluonye & Sargent, 2018; Tavoulari et al., 2015). Consequently, and as Oluonye and Sargent (2018) maintain, VI has an important impact on early childhood development and it would be important to consider the impact of neurodevelopment on young children with VI. What they suggest is that vision matures rapidly within the first year of life as the eyes, visual pathways, and the brain mature. VI might impact on all aspects of early development in the sense that skills may emerge much later than in children without VI. A very specific mention is made to echolalia, where, for example, the process of making requests could be prolonged, compared to children with no VI.
Young children often show a high degree of RBs that may trigger an alertness regarding the potential existence of autism in the child. These behaviours, however, diminish over time as other skills develop. Around the second year of life, some children exhibit a ‘developmental setback’, that might include loss of skills (Oluonye & Sargent, 2018, p. 382). Children with VI, then, are at greater risk of a developmental setback because of the limited or total loss of sight (Oluonye & Sargent, 2018).
Finally, Warren (1994) interprets RBs based on the motor activity which occurs in the attempt of the ‘non-seeing child’ to activate some of the senses that are still available to them. People without a VI construct their self-identity and the understanding of other people mainly based on vision. Babies and pupils with no VI use sighted behaviour (i.e., eye contact, joint attention, gaze following) to interact with others, especially during the pre-linguistic stage (Dale & Salt, 2008). Therefore, vision seems crucial for the child’s early development since the child tries to see and responds to social signs. Lack of vision might result in hindering the social development of a young child, who tries, as Bigelow (2003) and Urwin (1983) have noted, to use and compensate with the other senses (i.e., touch, olfactory, taste, hearing). That lack of mutual gaze between the baby and the caregiver was believed to have as a consequence an ‘asocial behaviour’ expressed as RB and characterised as ‘autistic’ (Fraiberg, 1977; Keeler, 1956; Wills, 1979) since similar behaviour is also observed in children on the AS.
Research in the VI field has shown that similar patterns of behaviour, namely RBs, such as spinning or head banging, occur in children with total vision loss and children with ASD (Cass, 1996). However, according to the study by Bogdashina (2005), RB is interpreted as ‘strange’, ‘bizarre’, and ‘obsessive’ with regard to children on the ASD, whereas for children with VI, it is thought to be ‘typical’ (p. 23).
Likely impact on the individual and their family
There is no specific research evidence regarding the impact RB might have on children’s families and their educators, but contextual evidence could arise from content-related research studies. As the above discussion shows, lack of sensory stimulation has been related as a cause of RBs in children with VI. It has also been asserted by Stone (1997) that RB frequently has as a consequence both the reduction of personal effectiveness and that of social exclusion. She says that the world is very demanding for individuals with partial or total vision loss, thus making them choose passivity and withdrawal by indicating ‘socially unacceptable’ behaviour (Stone, 1997, p. 95).
In addition to being socially unacceptable, some RBs can be harmful as well. For instance, Stone (1997) observed a child with VI, who had frequent episodes when he became very agitated at his play school, constantly poking at his eyes with his fingers. It was deduced that this was due to the noise of the central heating. This kind of behaviour can be characterised as self-harming and has been recorded in children with VI frequently by Gal and Dyck (2009) and should be stopped according to their suggestion. Singer (2009) and Stone (1997) highlight the need for distraction every time a child with VI presents a self-harming RB. Kingsley (1997) suggests that a self-harming RB looks alarming and might socially stigmatise the individual.
Research on the impact of RB on individuals with ASD and their families remains scarce, as asserted by Sethi et al. (2019). Leekam et al. (2011) claim that RB is a core feature for ASD that sometimes constitutes a major barrier to social adaptation. As C. Frith and Mira (1992) point, this was mentioned by both Kanner (1943) and Asperger. In some cases, actually, RBs are thought to be so disruptive for children, that medication is considered, even though, as Milton et al. (2016) argue, there is no medication to ‘treat challenging behaviour’ (p. 9).
Johnston and Hatton (2003) mentions in her biography the impact of perceptions where she points out that she was labelled ‘disruptive, attention seeking, rude, cheeky and deliberately awkward’, every time she was engaged in an RB (p. 11). These views suggest that the child is in control of their RB. However, Mullin (2014) in her book devotes an entire chapter to the description of imagery and repetitiveness found in all the artwork of the artists with ASD she researched, which shows the impact that RBs can have on individual thought process and that this is not an individual choice.
In another personal testimony of a child with ASD in Simmons and Sicoli (1996)’s book, the child says: ‘They call it ‘stimming’. All I know is that it makes me feel good even though mom says most people think it is strange’ (p. 4). It can be seen here that the mother’s assumptions about how others will view her son’s behaviour impacts her explanation. Perhaps because of this, RB has also been linked to elevated levels of parental stress (Orsmond et al., 2007). This could be because of how the behaviour is viewed by the wider society or the practical challenges that parents may have as a result of their child’s RB (Boucher, 2017).
Self-harming behaviour is not mentioned in the DSM-V as part of the diagnostic criteria for autism; however, it is considered to be a really important RB by Boucher (2017), which might have impact on the child and their social environment. It is usually expressed in the form of headbanging, self-biting, self-scratching, self-pinching, and self-hair pulling (Rojahn et al., 2016). Edgar Schneider (1999) explains in his book regarding an RB that occurred every time he becomes agitated: My first nervous breakdown (. . .) I slashed my forearm with my straightedge razor. (. . .) I and everyone else took it as a suicide attempt. (. . .) I did not want to die. Whenever I got angry, I would hurt myself before I would hurt anyone else. (p. 78)
This highlights that self-harming could be used as a self-management strategy by some. However, some research studies (Bodfish et al., 2000; Mooney et al., 2009; Turner, 1999) include self-harming behaviour as an RB, while some others (Bishop et al., 2006; Cuccaro et al., 2003, 2007; Richler et al., 2007; Shao et al., 2003; Szatmari et al., 2006) do not consider it at all, or just consider RB as a precursor to self-harming behaviour (Rojahn et al., 2016).
Interventions
Views on how to address or manage RBs seem to vary over the time. One of the early attempts at addressing the RBs of children with VI suggested that the RB should be curbed even through the use of pain or the introduction of new behaviours which would gradually replace the repetitive ones (Hayes & Weinhouse, 1978, Miller & Miller, 1976). Later, arguing that RBs do not seem to have a precise purpose, researchers (Brambring & Tröster, 1992; Gal et al., 2009; Tröster et al., 1991; Warren, 1994) suggested that there are compelling grounds to discourage, prevent, or redirect them, so that they become socially acceptable. Moss and Blaha’s (1993) mention of prejudice that seems to exist in people’s thinking about RBs and the fact that society needs to understand what an RB is and what kind of purpose it serves and addresses this behaviour accordingly.
For many years, it has been proposed that congenital VI can seriously disrupt infant and early development; therefore, early intervention and counselling (Fraiberg, 1977; Sonksen & Dale, 2002) have been a priority for children and parents, respectively, since the 1970s and have undoubtedly had an impact on the general developmental patterns in young children with VI and their caregivers (Dale & Sonksen, 2002; Pérez-Pereira & Conti-Ramsden, 2001, 2005; Sonksen & Dale, 2002). This has led to the reinforcement of the process of designing and implementing early intervention (Wiley et al., 2016). The intention was to develop the child’s strengths and increase the ability to overcome any constraints due to the lack of vision (Preisler, 1991; Sonksen & Dale, 2002; Sonksen & Stiff, 1991).
RBs in autism may inform intervention decisions as well (Wolfe et al., 2014). Some as, for example, Amaral et al. (2011) would argue that if the RB is curbed, then the child’s adaptability and flexibility could potentially increase, which will in turn enhance the overall trajectory of adaptive behaviour development and functioning.
Sethi et al. (2019) suggest that an intervention for eliminating RBs might not be the solution to the case, but accepting and adapting RBs on the part of family members could be as important step. Schneider (1999) supports such position by recounting that sometimes while exhibiting an RB ‘I was (. . .) treated as a pariah, and was subjected to epithets such as, ‘ You Nazzi bustard [sic]’ (p. 65). Such testimonies strengthen the argument for changing social attitudes as an intervention priority. The goal would basically be to understand and probably change people’s perceptions and attitudes towards RBs (Moss & Blaha, 1993). The aim to eliminate RBs would be the option only in the self-harming cases.
In conclusion, while RBs are part of the diagnostic criteria for autism, there is also a focus on their cause and how these can be reduced. Researchers (Carrington & Graham, 2001, p. 45; Kogan et al., 2008, p. 1149; Sethi et al., 2019) suggest that these are a result of stress due to unpredictability, but some still take the view that they either have to be eliminated or stopped. This view is taken by some researchers despite what individuals on AS state as the reasons for their RB.
Discussion
Perceptions are defined as a subjective experience and an entirely subjective process (Solms & Turnbull, 2010). Hopp (2011) claims that everybody has a ‘second nature’, which is defined by their upbringing, cultural perceptions, practices, and language (p. 97). That ‘second nature’ enables people to perceive facts instantly and passively and this might impact on how they respond to them. There is a reason-giving relation between experiences and beliefs that explains why a person finds something to be as they think it to be. Eleftheriou (2009) asserts that different societies have different support and knowledge. She also claims that the offered knowledge and support reflect people’s perceptions, and any type of prejudice and social barrier.
Ecological system theory provides a useful framework to understand these individual or collective beliefs and the way different aspects of the society interact. Education is considered a social matter that could be viewed through this theory as well (Yue-Guo, 2005), so as to enable individuals to bring either their knowledge, or values or perceptions and emotions into every situation. Students, who are always placed in the centre of the ecological systems, interact with individuals from the microsystem and are affected by the personal values of these individuals. Therefore, understanding perceptions of key stakeholders is important, mostly because the way people experience an RB seems to be having an impact on their ability to support the person with VI or with ASD. The perceptions of caregivers and professionals concerning children’s RB and its impact on the life of both the former and the latter do not seem to be a primary research aim in the past research studies and the reason for this is not clear.
Following the literature search, no specific source emerged with regard to the perceptions of wider community concerning RB that children with VI might present. The key information that was found in relation to children with VI in general, was that their parents react depending on the way the surrounding environment handles the situation involving the child with VI (Sioutis, 2012). If the surrounding environment accepts the child’s disability, then the family itself can accept them more easily. No research evidence was found in relation to people’s perceptions about the RB of children on the ASD either. This gap in the literature is initially commented on by Fletcher-Watson et al. (2017), who observed that researchers should endeavour to continue to take community perceptions into account.
While research may not have specifically explored wider community perceptions, existing literature that defines RBs, explores its causes, and suggests ways to intervene provides an insight into the perceptions of the society and how they are similar or different when it comes to children with VI and ASD. Understanding these conceptual frameworks is important (Cote & Nightingale, 2012, p. 475), which highlights the importance of ‘human-environment dynamics’ where they suggest that a child’s environment affects how that child grows and develops. Part of this environment is the definition of disabilities and how support is provided to children with disabilities. According to the study by Kamenopoulou (2016), policies (e.g., special education governmental policy, schools’ policy on special education, World Health Organisation’s diagnostic criteria for disabilities) are flexible frameworks that are continually being reconstructed to meet the professionals’ requirements. This highlights that the ‘human-environment dynamics’ includes professionals and researchers working in the field as their views and research priorities have an impact on the policies and diagnostic criteria developed to support children with VI or ASD and their families. In this context, the lack of research interest in comparative studies of ASD and VI is worrying.
This literature review has found that there are differences in how RBs are defined in the fields of VI and autism. Within the field of VI, the focus seems to be mainly on sensory-motor behaviours. Whereas, in autism, RBs are defined as a broader category that includes cognitive processes, such as special interests and following routines or rituals. What is also notable is that while RBs are part of the diagnostic criteria for autism, this is not the case for VI. Even with this broader definition of RBs in autism, self-injurious behaviour is not considered as an RB in most of the research, nor included in the ASD diagnostic criteria. This highlights the fluidity and murkiness of some of the concepts.
The fact that RBs are part of autism diagnostic criteria may have also led to a lack of interest in comparative studies with VI in the autism research. In VI, RBs were referred to as ‘autistic behaviours’ by some of the authors, but there is still very little deeper analysis of the similarities and differences of causes between the two conditions.
This difference in definitions and whether RBs are part of the diagnostic criteria or not, may have affected research about the causes and thereby the development of interventions in the field of autism compared to VI. Although wider contextual factors such as difficulties in communication and boredom have been mentioned as possible reasons for RBs in children with VI, lack of visual stimulation has been considered as the primary reason for RBs. Therefore, intervention strategies focused on developing early intervention. In autism research, a wider range of causes, such as sensory-processing differences, lack of social understanding, and stress, are quoted as potential causes for RBs. Therefore, teaching flexibility, social skills, and making the world predictable are suggested as potential intervention strategies.
Many of the existing research studies have been focused on interventions with the children rather than on adjusting the adults’ behaviour (Bradshaw, 1998; Kossyvaki et al., 2016). However, it is not only the way the child is treated that is important but also the way parents are treated by those who are involved professionally with the child, and also how the wider society accepts differences. We could not find much literature that specifically explored the impact of RBs on families. However, the autobiographical works where individuals on the AS have mentioned about their experiences suggest a wider level of stigma and misinterpretation of RBs. It is likely then that families would feel stigmatised because of their child’s behaviour. Although fewer personal narratives of experiences of RBs are available from individuals with VI, some of the existing research does point towards families who experience high levels of stress and feeling stigmatised because of their child’s behaviour.
Conclusion
This literature review draws attention to the paucity of comparative research in the fields of VI and ASD when understanding RBs. This lack of research interest could be because of how VI and autism are defined, and the causes for RBs are understood in the respective fields.
There are some similarities in family experiences as parents of both groups of children have stated high levels of stress and feeling stigmatised because of their child’s behaviour. The commonality is also found in the way interventions are developed in both fields where the emphasis is often on changing the behaviour of the child.
There is a need for further research in the field to develop understanding of RBs in different conditions, such as VI and autism.
This is the reason we believe it could be elucidating if comparative studies on VI and ASD could be conducted, concerning, in particular, the link between VI and ASD. Both disabilities share characteristics that could lead to important findings and insights about the impact they have on the people who live with or care for the children with VI or ASD. This kind of comparative study could be illuminating as well, regarding the way people conceptualise RBs.
Footnotes
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The research study based on the gap emerged from that literature review received grant from the Swiss Leventis Foundation and funding from the Greek Bakalas Foundation.
