Methods: By reviewing the strengths and limitations of the models: health belief model, theory of planned behaviour and human ecological systems we constructed an appropriate framework that respectful of cultural traditions and religious beliefs in traditional societies found in a changing social environment and struggling with the vast number of global influences.
The Health Belief Model (HBM), a widely used model in health promotion to predict health behaviour, is based on the premise that people are most likely to take health-related action, if they feel that by doing so, they can avoid a negative or risky health condition or adverse event (Becker et al., 1977). This model provides a framework for understanding health behaviours and health-related risk taking, including sexual risk behaviours among various ages, by diverse cultural groups and within their social environment. The pioneering development of the HBM in the early 1950's incorporated the impact of social and other factors associated with inequalities in health and provided explanations on why individuals and groups may or may not engage in actions that improve or protect health. However, available evidence indicates that the HBM components are insufficient to predict "real world" applications (Armitage & Conner, 2000).
The theory of planned behaviour (TPB), a social cognitive model and modification of the theory of reasoned action, provides a framework for understanding an individual's voluntary behaviour. The TPB assumes that human beings are generally quite rational and tend to systematically use the information available to them. The theory contends that people estimate certain factors before deciding to engage or not to engage in a behaviour (i.e., intent factor). According to the TPB, intention when not influenced by unforeseen circumstances that limit an individual's control, predicts future behaviour. The variance in intention is composed of three global constructs: attitude toward the behaviour, subjective norms, and control (Ajzen, 2001). Nevertheless, the TPB is insufficiently specific in its measurement of behaviour; it investigates the interrelationships between model constructs and a single behaviour, but fails to consider alternative behaviours (Sniehotta, Presseau, & Araújo-Soares, 2014). In addition, the model relies strongly on cognition and omits other potentially important determinants of behaviour, such as environmental influences comprising the source of beliefs, their assessments, and associated emotions. Consequently, these "rationale" beliefs fail to capture the universe of factors that influence behavioural decision-making (Sniehotta et al., 2014).
The Human Ecological Systems Model (HESM), also called human ecology theory, provides the framework for studying the relationships within individuals' contexts, their communities and the wider society. This theory asks the question: how are individuals' behaviours affected by their social relationships and the world around them? The HESM, developed by Urie Bronfenbrenner in the 1970's, suggests that a person's development is affected by everything in their surrounding environment. He identified four environmental systems within which an individual interacts: the microsystem, the mesosystem, the exosystem and the macrosystem (Bronfenbrenner, 1977). According to Bronfenbrenner, human behaviour is shaped by the interaction of these varied systems within our social and physical environment and the interrelationships among the systems. Relationships between the human and the environment are reciprocal; the environment influences the human and the human influences the environment. Human beings, Bronfenbrenner suggested, cannot develop in isolation, but within a system of relationships that include family and society. This major theoretical breakthrough provided additional understanding to the complicated issues such as adolescent sexuality in the changing traditional society (James, 2014; Jan-erik, 2017) . However, a major limitation of the HESM is that it conceptualises adolescent's behaviours from a very general perspective, that are more related to western and modern cultural norms (Rowley et al., 2015). From a traditional society perspective, social determinants can include other significant influences such as, social norms, cultural taboos, gender roles, religiosity, health equity and political factors.
Human behaviour, including adolescent's sexual behaviour, is not a matter of an individual's motivations alone. We act within social contexts. Adolescents develop through interaction with many social systems (i.e., families, peers, school, community, religion, society, and international media)(Lesenciuc, 2017). For adolescent sexuality within a traditional society, a new model is needed. One that depicts the holistic approach and the multiple levels of interactive influences that arise from a rapidly changing community that may affect an adolescent's sexuality. The proposed model is based and built on the foundations of the above-mentioned theories, and incorporates knowledge, attitude and behaviour from HBM and TPB, and the HESM's multiple layers of social environment and systems influencing the individual.
Results: The proposed Galaxy model (GM) adds: (1) The different factors and variables have strong bonds, creating a system that is not hierarchical and is hard to tease-apart. That is, global changes do not need to permeate through community and family to influence the adolescent, they have direct effects on the adolescent through online social network; (2) A dynamic, continuous and interchangeable movement of affecting variables influences the adolescent; (3) There is a mutual, however uneven, interaction of influences among the variables on the adolescent; (4) The relationship between the adolescent and environment may not easily be susceptible to change; (5) Changes that can emanate from globalisation versus society versus community may influence youths in completely different ways. As such, the proposed model recognises the importance of individual aspects as well as multi-level environmental influences and the interactions among them as key to understanding adolescents' sexual behaviour and attitudes. The proposed model has the potential, first to identify contributors to adolescents' sexual knowledge, attitudes and behaviour; and second, to recognise and measure the contributions of cultural and social factors which must be considered when designing intervention programs and policies targeting adolescents' sexuality in a traditional society. Moreover, the Galaxy Model adds the complexity of the external factors emanating from the dynamic changes from the global environment (modernisation, media, social networks), the society (traditional society) and the community (family, school, peers). These changes combine to influence the behaviour of adolescents. Additionally, the GM adds specific internal factors (i.e., physical, cognitive and spiritual) on adolescents' sexual knowledge, attitudes and behaviours. The GM connects these dynamic and cyclical internal and external factors on the adolescents' knowledge, attitude, and behaviour.
Conclusion: This model is designed for understanding adolescents' behaviours in a society undergoing the sometimes-dramatic collision between the morays and beliefs of traditional culture, its reactions to modern influences, and the resulting transitions in its norms. The GM aims to better explain the multi-dimensional and specific influences on adolescent's sexuality, a very sensitive subject within traditional societies, as it experiences shifts in its social environments.