Applied Psychology OPUS

The Relation Between Perceived Decision Freedom and Resilience: An Analysis of Eight Urban Adults Living in Morocco

Jazmine Russell

According to the most recent report by The United Nations Population Division, approximately 54% of the current global population lives in urban areas, and numbers are expected to increase over the years (United Nations, 2014).  Research on urbanization shows that individuals living in urban neighborhoods may be more exposed to a variety of daily life stressors that can lead to psychological and physical health risks (Wandersman & Nation, 1998). For example, urban cities are often environments fraught with air pollution, poor sanitation, transportation issues, and noise pollution, all of which cause stress to inhabitants (Baum, Singer, & Baum, 1981; Vlahov et al., 2007). Additionally, urban contexts often contain layers of social and economic structures that can lead to negative outcomes, including SES disparities, cultural clashes, crowding, social isolation, violence, and crime (Mullen & Arce, 2008; Stockdale, Wells, Lingqi, Belin, Zhang, & Sherbourne, 2007).  Many studies on urban populations have concluded that the myriad of stressors related to urban life can significantly contribute to various mental health issues such as depression, anxiety, and substance abuse (Baum et al., 1981; Mullin & Arce, 2008; Wandersman & Nation, 1998).
The vast amount of negative outcomes associated with urban life have encouraged researchers to investigate factors that can improve an individual’s ability to adapt (Baum et al., 1981; Wandersman & Nation, 1998). Resilience is a term often used to describe one’s development of adaptive coping strategies despite being challenged with various life-stressors (Luthar & Zigler, 1991; McGloin & Widom, 2001; Mullin & Arce, 2008). Researchers find that resiliency and positive coping strategies are contingent upon both external social support and internal dispositions (Dyer & McGuinness, 1996; Lever, Piñol, & Uralde, 2005; Masten & Garmezy, 1985). More specifically, one’s perception regarding the controllability of life circumstances prove to be a significant indicator of resilience (Cornelius & Averill, 1980; Lefcourt, 1973; Lefcourt, Martin, & Saleh, 1984; Steiner, 1970). The belief that one is in control of their circumstances and free to make decisions towards desired outcomes is what researchers call perceived decision freedom (Steiner, 1970). Typically, those who display high levels of perceived decision freedom also feel more in control and are less affected by life stressors, and therefore, demonstrate more resilience (Lefcourt, 1973; Luthar & Zigler, 1991; Perlmuter & Monty, 1977). This study will review the literature on the relationship between resilience and perceived decision freedom in urban individuals who are faced with life stressors and analyze this relationship in a sample of urban adults living in Morocco.

Factors Mediating Life Stress and Resilience

Research indicates that resilience is fostered both by social support and individual dispositions, which serve as protective factors against life stress (Dyer & McGuinness, Luthar & Zigler, 1991; Mullen & Arce, 2008; Wandersman & Nation, 1998). Both social support and individual dispositions can shape an individual’s coping strategies and adjustment to daily stress in urban neighborhoods (Mullen & Arce, 2008; Wandersman & Nation, 1998). Social support in an urban context can manifest as familial warmth, trusting relationships with neighbors, and access to community services (Stockdale et al., 2007). With more social support, individuals tend to have more resources for overcoming the potential difficulties of urban life and are less likely to have related mental health issues (Luthar & Zigler, 1991; Wandersman & Nation, 1998). Similarly, individual dispositions such as one’s sense of self, determination, and pro-social attitudes can also shape stress responses and affective coping (Baum et al., 1981; Dyer & McGuinness, 1996; Rutter, 1987). For example, urban stressors such as commuting issues or neighborhood violence can bring up feelings and beliefs regarding the unpredictability of the situation, confidence in one’s ability to overcome the challenge, and one’s ability to regulate emotions around the event (Baum et al., 1981; Lever et al., 2005; Mirowsky & Ross, 1990). Since urban neighborhoods are generally more stressful environments with greater instances of social isolation and greater risk for mental health issues, it is even more crucial to develop social support systems and positive dispositions in these contexts (Stockdale et al., 2007).
Researchers have indicated one specific factor, an individual’s belief about the controllability of life stressors, as particularly important in fostering resilience (Cornelius & Averill, 1980; Lefcourt et al., 1984; Lever et al., 2005; Veitch & Gifford, 1996). In recent literature, this construct is referred to as locus of control. Locus of control is a term used to indicate whether an individual believes events to be a result of their own decisions or other uncontrollable circumstances (Lefcourt et al., 1984; Lever et al., 2005). However, a corresponding term, perceived decision freedom, addresses the same construct and both terms have been used interchangeably in the literature. Both locus of control and perceived decision freedom research states that individuals with a sense of control: a) believe they are free to make their own decisions, b) take responsibility for these decisions, and c) believe their decisions can lead to desired outcomes (Lever et al., 2005; Perlmuter & Monty, 1977; Steiner, 1970). For the purposes of this study, perceived decision freedom will be used as the operationalized term.

Choice, Control, and Resilience

Studies show that individuals with higher levels of perceived decision freedom tend to be more resilient (Cornelius & Averill, 1980; Mirowsky & Ross, 1990; Veitch & Gifford, 1996). This association is attributed to the fact that individuals who believe their decisions can produce positive outcomes have a greater sense of volition (Lefcourt, 1973; Lefcourt et al., 1984). They are, therefore, more likely to be motivated to achieve desired outcomes and not feel helpless when faced with difficulties (Perlmuter & Monty, 1977). Research shows that individuals with high perceived decision freedom have more adaptive coping strategies and even benefit more from other protective factors, such as social support systems, than those who believe events are uncontrollable and unrelated to their decisions (Lefcourt et al., 1984).
Perceived decision freedom is important in an urban context because studies show that stress is highest when an event is both unpredictable and uncontrollable (Lefcourt, 1973; Perlmuter & Monty, 1977). When an individual perceives himself or herself to have limited choice and control in a situation, for instance being stuck in traffic or becoming a victim of crime, there is a greater risk for feelings of anxiety, fear, hopelessness and depression (Çelik, Çetin, & Tutkun, 2014; Cornelius & Averill, 1980; Luthar & Zigler, 1991; Stockdale et al., 2007). Conversely, if an individual has a greater amount of perceived decision freedom in an event, they typically are more motivated to seek help, access resources, and have less aversive reactions to the stressor, therefore displaying more resilience (Cornelius & Averill, 1980; Perlmuter & Monty, 1977). Many researchers agree that a sense of control and active problem-solving are crucial to resilience and mental health (Perlmuter & Monty, 1977; Rothbaum, Weisz, & Snyder, 1982).

Multi-cultural Views on Decision Freedom

On an international level, studies show that perception of control is a primary factor in life-satisfaction and well-being across nations (Minkov, 2009; Spector et al., 2001). While some researchers agree that more freedom to decide can aid in motivation for success, low stress levels, and more resilience, others point out that these assumptions about freedom and autonomy are very Western concepts that presuppose certain assigned values (Markus & Schwarz, 2010). Many Americans believe that more choice means more freedom and more freedom means more well-being, however, these assumptions stem from the cultural values of autonomy, individuation, and personal expression (Markus & Schwarz, 2010). Alternatively, for more collective cultures, choices can be a representation of social compliance and respect for others, as life outcomes can be predetermined by one’s family or social group and less contingent on one’s personal decisions (Markus & Schwarz, 2010; Spector et al., 2001). For cultures that value social relationships more than individuality, freedom may not always be considered positive or adaptive. For example, some individuals perceive too much freedom as negatively impacting their sense of control (Markus & Schwarz, 2010). Therefore, it’s important to consider how these cultural meanings and values assigned to choice and freedom may affect the ways in which individuals display resilience (Çelik, Çetin, & Tutkun, 2014; Markus & Schwarz, 2010).

Many researchers agree that resilience is contextual and culturally defined, meaning it is dependant upon specific social contexts and attitudes towards well-being (Çelik, Çetin, & Tutkun, 2014; Vlahov et al., 2007). Although there has been some cross-cultural research done on differences in autonomy and well-being between individualistic and collective cultures, most research assumes a general positive relationship between sense of control and well-being. Very little research has explored cultures outside of the polarizing collectivist-individualist distinction or attempted to describe beliefs about sense of control, freedom, or well-being, and what they might mean to individuals of different cultures.

Present Study

Therefore, the present study explores the relationship between perceived decision freedom and resilience in 8 adults living in urban areas in Morocco, which is a country that is highly under researched, has a variety of cultural influences, and cannot be categorized as typically collectivistic or individualistic. This study is part of a larger project, conducted at The Ultra Laboratory in Casablanca, Morocco, that looks at the ways in which multicultural  individuals living in Morocco express their values, beliefs, experiences, and meaning-making systems that constitute their reality. This study is exploratory, as little research has been conducted on these topics outside of the United States. Morocco contains large, diverse urban cities, which may include similar life stressors as in American cities, however, there may be reason to believe that perceptions of decision freedom and resilience may differ in Moroccan individuals due to potential differences in cultural values.   

Method
Participants

 The participants were selected by convenience sample and most were recruited through social media and email via connections that The Ultra Laboratory had previously established with the community. Two participants were specifically sought based on their participation and activism in the artistic communities in Morocco. The sample for the current study includes 2 females and 6 males ranging from 20 to 54 years old. 6 of the 8 participants are artists including writers, visual artists, and performers. All of them are at least bilingual. 5 speak French, Arabic, and English, 2 speak French and English, and 1 speaks French and Arabic. Their language proficiency in English and French is indicative of high education levels and a relatively high SES, since, in Morocco, only those in moderately wealthy families can afford to either travel or attend schools which teach languages other than Arabic. 5 out of 8 participants have lived outside of Morocco for an extended period of time, typically in urban cities in France or the US, and consider themselves to be multicultural.

Procedure


 The study consists of 30-60 minute long semi-structured interviews asking open-ended questions regarding how individuals perceive reality, how they view subjectivity and objectivity, how they feel about the ambiguity in life, if they feel a sense of freedom and control in their lives, and how their culture has shaped their beliefs. The interviews were structured loosely in order to give the participants the flexibility to bring up any stories, beliefs, or ideas they considered relevant.  The interviews were recorded on a Sony ICD voice-recording device. Participants were assured that, if preferred, their identities would be kept private and a pseudonym would be used instead. All interviews were conducted in English at a location that the participant chose where they would feel most comfortable. Only one interview was conducted in French, whereby an assistant of the project acted as an interpreter between the primary investigator and the interviewee. As a precautionary step, this interview was again translated by a second assistant who listened to the recording of the interview to provide further clarification on the interviewee’s responses.
The interviews were thematically analyzed to explore three questions: 1.  In which ways do the participants perceive themselves to be limited or free to make their own choices in life? 2. In which ways do the participants display attributes of resilience? 3. How do instances of perceived decision freedom relate to instances of resilience across the participants? To address the first question, participants were asked “How much freedom or choice do you feel you have in life?” This question is used in this study as a measure of perceived decision freedom. The responses to this question were analyzed with the intent of finding whether or not the participant felt in control of his or her life and what he or she perceived as limitations to control and freedom.  To address the second question, the data were analyzed for ways in which the participants coped with difficulties, thereby displaying resilience. Resilience is operationalized according to the definition by Luthar & Ziglar (1991) as any instance of overcoming difficulties and developing adaptive coping strategies. The constructs were then analyzed in tandem to assess the relationship between perceived decision freedom and resilience as demonstrated in the interviews.
 
Results
Perceived Decision Freedom

Mental/Emotional Freedom.  Many participants perceived themselves to be either free in their mental/emotional life or hindered by mental/emotional conflict. Some examples of mental/emotional conflict include feeling “trapped” in their mental states, being overpowered by negative emotions such as anger, feeling afraid to seek out opportunities, and feeling at the mercy of these emotions. However, almost all participants cited examples or discussed the importance of keeping the mind free, exerting control over emotions, letting go of all “mental baggage” and being open to possibilities. Participants practiced mental freedom by using specific techniques, for example by “visualizing throwing out all these bad feelings that you’ve been carrying around with you” or, more simply, by “open[ing] yourself to possibility and relax[ing].”  

Spiritual Freedom. Throughout the interviews, spiritual beliefs were discussed as major components in perceived decision freedom. 6 out of 8 participants directly reported believing in God or a higher power and four participants also discussed their belief in destiny, believing that “everything happens for a reason.” These participants also reported feeling free to make their own small decisions in daily life, but simultaneously felt a predetermined purpose in their life, particularly that certain people affected their lives and choices in predetermined and meaningful ways. However, regardless of religion or spiritual orientation, many participants also discussed their spiritual belief as a choice in itself. Many stated that it was a personal decision to choose a religion or ideology after exploring many different belief systems. Therefore, spiritual beliefs can be freely chosen, but also influence perceived decision freedom.

Social/Cultural Freedom. Some participants mentioned the usefulness of social support in giving them resources and opportunities in life, while others found ways to exert their freedom independently of others. More specifically, familial support or lack thereof was often discussed as a primary influence in the participants’ decision freedom. Some reported that their families and socio-economic status either allowed for opportunities such as travel and education, or limited their choices by enforcing traditions and impeding certain desires. However, some participants who did receive social support did not always interpret the freedom gained through this support as necessarily positive. For example, one interviewee described her family as relatively wealthy, supportive, and open, allowing her to study art in school and to decide whether or not she wanted to take part in Islamic traditions. Although she values her “open-minded education,” she also recognizes that “it gives you so much freedom that you have a hard time knowing who you belong to – where you belong to.” Feeling the freedom to explore was a commonality between participants, since they are multicultural and have been exposed to multiple cultures and beliefs. Many participants report gaining freedom and opportunities from these multicultural experiences, or feeling “trapped” when they do not have the chance to travel or communicate with different kinds of people. However, all of the participants reported sometimes feeling alienated, unable to fit in, or pressured to conform, thereby hindering personal freedom and limiting choice.

Resilience

Spiritual Coping Strategies. Spirituality was often reported by participants as a means both to cope with daily life stressors and to find long-term hopefulness. Some described techniques such as yoga, meditation, visualization, connecting the body and mind, and other religious practices as ways to keep a sense of inner peace despite life stress. In addition, many concluded that spirituality is essential in maintaining hope, and reported that spiritual beliefs give them “resources” and “another dimension to think, to feel, to hope.”

Self-Growth. Throughout the interviews, all participants revealed the desire and motivation to improve themselves despite being faced with personal and life difficulties. Several different themes relating to self-growth emerged throughout the interviews. For example, many participants described their personal goals, dreams, and persistence in the presence of challenges. Not only did most participants show perseverance, but also revealed confidence in their ability to succeed and maintained optimism and faith in the eventual attainment of their goals. Additionally, many participants revealed a desire for self-knowledge and inner peace, attempting to “get in touch with [the] inner self”. Times of difficulty for the participants were often associated with a lack of self-understanding. One participant describes a difficult but rewarding transition from a time when she was “not conscious of what [she] was feeling” to finally discovering her inner emotions, attempting to “listen to [her] inner world.” The act of embracing a personal transformation was common throughout the participants’ stories. Typically, this act of transformation meant either learning to accept oneself and one’s life circumstance or adapting to changing life circumstances. Since many of the participants are artists, they also expressed the desire to cope with these transformations and explore the inner self through art.

Having/Gaining Social Support. Social support was often cited by participants as a major factor that helped them overcome difficulties, find resources, and reach their goals.  Reaching out to others was a common practice across participants, since many felt as though their own lives have been improved by “learning from people,” “sharing knowledge,” or “staying connected” and asking others for help. Solidarity and working together were common themes that arose, giving participants a sense of strength in the face of difficulty. However, several participants admitted to feeling a lack of social support, either from their family, from those who misunderstand or reject their goals, or as a result of growing up multicultural and being surrounded by people who are different from them. Feeling a lack of social support was often associated with a sense of alienation, but it also encouraged the use of other coping strategies. Those who felt alienated reported eventually becoming willing to adapt, either by conforming to the norm or by accepting one’s own differences. Therefore, even during times where participants did not feel supported or accepted, they overcame these difficulties by learning to find comfort in “this mere singularity of each person” and the understanding that despite cultural differences “we are all trying to make it in a very difficult world and everybody is struggling with his own self.”

The Interaction Between Perceived Decision Freedom and Resilience

In general, this study shows perceived decision freedom and resilience to have a bidirectional relationship, meaning that the more perceived decision freedom that the participant has, the more positive coping strategies he or she seems to have developed. Additionally, the more resilience each participant displays, the more possibilities and choices he or she seems to have in his or her life.  For instance, those who felt mentally and emotionally free from constraint or open to possibilities also tended to have more resilient dispositions such as hopefulness, optimism, or self-confidence. Similarly, those who sought inner peace and embraced transformation through difficult times also felt more freedom and control over their mental/emotional life. In the spiritual domain, those who felt free to explore and choose from different belief systems also utilized these beliefs to develop different coping strategies. In addition, those who developed the positive coping strategy of seeking social support also generally gained more possibilities and choices through these connections. However, this positive relationship between perceived decision freedom and resilience is yielded across categories as well, with mental/emotional, spiritual, and social domains of freedom and resilience all interacting together. Generally, individuals who displayed higher levels of perceived decision freedom and resilience in one category also displayed them in other categories as well.

Discussion

Several themes yielded in this study remained consistent with previous literature. Resiliency yielded themes consistent with the commonly mentioned protective factors of social support (e.g. familial support and reaching out to others) and individual dispositions (e.g. hope/optimism, self-confidence, and persistence). Perceived decision freedom was also found to act similarly in this study as in prior research, meaning those who felt free to make decisions and choices in life cited examples of feeling in control and motivated to carry out their goals based on these decisions. In addition, this study more clearly demonstrates several specific ways in which perceived decision freedom and resilience are related, as merely theorized in previous literature. For example, consistent with Rutter’s (1987) description of resilience, results show that feeling free to open oneself to possibilities is an important attitude that fosters resilience. Secondly, this study is in agreement with the idea by Rothbaum, Weisz, and Snyder (1982) that adaptation and coping are ways of maintaining a sense of control. For example, many participants cited examples of adapting to life circumstances either internally, through changing emotions or perceptions, or externally, by changing behaviors. Through adaptation, they, therefore, felt more in control and free to make more adaptive decisions.  

However, both resiliency and perceived decision freedom acted within an uncommon category that was not heavily mentioned in prior literature: spirituality. Contrary to the literature, several participants held the belief that certain events were predetermined and uncontrollable, which for them still promoted a sense of hope and resilience in the face of difficult circumstances. However, this association may be explained by the fact that no participant relinquished all control to a higher power. Within what they considered to be unavoidable circumstances, participants mentioned still feeling free in how they thought, felt, and reacted to circumstances. It is, therefore, difficult to determine what role perceived decision freedom played in resiliency and coping strategies stemming from spiritual beliefs.

Another interesting result is the participants’ focus on multicultural interactions, which appear to be specific to the study sample and not mentioned in previous literature. All participants described the act or the desire to travel and communicate with people of different cultures. Many described exposure to different cultures as positive, both providing opportunities for personal growth and giving them more choices in life. In this way, multicultural exposure seems to increase both resilience and perceived decision freedom. However, these same participants also cited instances when they felt alienated and pressured to conform or adapt as a minority in the context of a larger culture. In response, most participants stated even the negative aspects of multicultural exposure gave them the opportunity to respect their own and others’ differences. They, therefore, gained positive opportunities for self-growth despite the negative emotions involved. This emphasis on travel and exposure to different cultures may be an interest that is specific to these individuals, since they all identify as multicultural. Additionally, the focus on multiculturalism and travel could be related to the participants’ identity as Moroccans. As one participant explained, Morocco can be likened to a “tree with it’s branches rising up towards Europe but its roots deep in the African soil, and to the east there’s the Arab world and beyond it is Asia, and to the west there’s the United States and the new world.”

Limitations

This study contains a small sample size and is, therefore, not generalizable. There is also a sampling bias since participants were selected through connections held by the artist residency owner. The selection pool, therefore, only contained artists and art-enthusiasts, which may have affected the results. All 8 participants are of similarly high SES and education level, which does not represent other populations also living in urban neighborhoods in Morocco. Additionally, though the participants were of Moroccan heritage, they were also exposed to many different cultures, which could have influenced their belief systems, coping strategies, and ways of perceiving freedom. Since the interviews were structured loosely and participants were not directly asked to discuss coping strategies or instances where they had to overcome difficulties, some participants were more open than others about life stressors and challenges, which could have influenced results.
 
Future Directions

Since this was an exploratory study, future research should develop more specific interview questions regarding perceived decision freedom and resilience allowing the constructs to be statistically compared. Research would also benefit from a larger sample of a broader variety of individuals in Morocco from different SES backgrounds. Studies show that SES is an important factor related to both perceived decision freedom and resilience (Lever et al., 2005; Wandersman & Nation, 2008). Those with lower SES tend to have more limited resources, access to community services, and are more socially isolated in urban communities (McGloin & Widom, 2001; Wandersman & Nation, 2008). These individuals tend to have fewer choices and lower levels of perceived decision freedom, which studies show can lead to more maladaptive coping strategies and increased mental health risks (Lever et al., 2005; Mullen & Arce, 2008).  It is, therefore, even more crucial to look at perceived decision freedom in these populations as they are more vulnerable to risk-factors that can hinder resilience (Luthar & Zigler, 1991; McGloin & Widom, 1991).

References

Baum, A., Singer, J. E., & Baum, C. S. (1981). Stress and the environment. Journal of Social Issues, 37(1), 4-35.

Çelik A.D.,  Çetin, F. & Tutkun, E. (2014). The role of proximal and distal resilience factors and locus of control in understanding hope, self-esteem, and academic achievement among Turkish pre-adolescents. Current Psychology, 1-25.

Cornelius, R.R. & Averill, J.R. (1980). The influence of various types of control on psychological stress reactions. Journal of Research in Personality, 14. 503-517.

Dyer, J. G. & McGuinness, T. M. (1996). Resilience: Analysis of the concept. Archives of Psychiatric Nursing, 10(5), 276-282.

Lefcourt, H.M. (1973). The function of the illusions of control and freedom. American Psychologist, 28, 417-425.

Lefcourt, H.M., Martin, R.A., & Saleh, W.E. (1984). Locus of control and social support: Interactive moderators of stress. Journal of Personality and Social Psychology, 47(2),  378-389.

Lever, J.P., Piñol, N.L., & Uralde, J.H. (2005). Poverty, psychological resources, and subjective well-being. Social Indicators Research, 73, 375-408.

Luthar, S.S & Zigler, E. (1991). Vulnerability and competence: Review of research on resilience in childhood. American Journal of Orthopsychiatry, 61(1), 6-22.

Markus, H.R. & Schwartz, B. (2010) Does choice mean freedom and well-being? Journal of Consumer Research, 37(2), 344-355.

Masten, A. S. & Garmezy, N. (1985). Risk, vulnerability, and protective factors in developmental psychopathology. In B. B. Lahey et al. (eds.) Advances in Clinical Child Psychology (1-52). New York: Plenum Press.

Minkov, M. (2009). Predictors of differences in subjective well-being across 97 nations. Cross-Cultural Research, 43(2), 152-179.

Mirowsky, J & Ross, C.J. (1990). Control or defense? Depression and the sense of control over good and bad outcomes. Journal of Health and Social Behavior, 31, 71-86.

McGloin, J.M. & Widom, C.S. (2001). Resilience among abused and neglected children grown up. Development and Psychopathology, 13, 1021-1038.

Mullin, W.J. & Arce, M. (2008). Resilience of families living in poverty. Journal of Family Social Work, 11(4), 424-440.

Perlmuter L.C. & Monty, R.A. (1977). The importance of perceived control: Fact or Fantasy? American Scientist, 65(6), 759-765.

Rothbaum, F., Weisz, J.R. & Snyder, S.S. (1982). Changing the world and changing the self: A two-process model of perceived control. Journal of Personality and Social Psychology, 42(1), 5-37.

Rutter, M. (1987). Psychosocial resilience and protective mechanisms. American Journal of Orthopsychiatry, 57(3), 316-331.

Spector, P.E., Cooper, C.L., Sanchez, J.I., O’Driscoll, M., Sparks, K., Bernin, P….Yu, S. (2001). Do national levels of individualism and internal locus of control relate to well-being: An ecological level international study. Journal of Organizational Behavior, 22, 815-832.

Steiner, I. (1970). Perceived freedom. Advances in Experimental Social Psychology, 5, 187-248.

Stockdale, S. E., Wells, K. B., Lingqi, T., Belin, T. R., Zhang, L., Sherbourne, C. D. (2007). The importance of social context: Neighborhood stressors, stress-buffering mechanisms, and alcohol, drug, and mental health disorders. Social Science & Medicine, 65, 1867-1881.

Veitch, J.A. & Gifford, R. (1996). Choice, perceived control and performance decrements in the physical environment. Journal of Environmental Psychology, 16, 269-276.

Vlahov, D., Freudenberg, N., Proietti, F., Ompad, D., Quinn, A., Nandi, V., Galea, S. (2007). Urban as a determinant of health. Journal of Urban Health: Bulletin of the New York Academy of Medicine, 84(1), 16-25.

Wandersman A. & Nation, M. (1998). Urban neighborhoods and mental health: psychological contributions to toxicity, resilience, and interventions. American Psychologist, 6, 647-656.

United Nations, Department of Economic and Social Affairs, Population Division (2014). World Urbanization Prospects: The 2014 Revision, Highlights. Retrieved from http://esa.un.org/unpd/wup/Highlights/WUP2014-Highlights.pdf