Applied Positive Psychology Epigenetics and Obesity
Paper details:
This is a 3000 word positive psychology article for publication in a peer reviewed journal. The paper must be edited and pass for publication. The references should be listed as 1,2,3, in the text and not as it is now done with names and dates.In the reference list they should be numerical and not alphabetical.
This article gives an understanding of Positive Psychology (PP) as an evolutionary discipline, Applied Positive Psychology (APP) as its arm of practice and Positive Psychology interventions (PPI) as the tools of trade. The paper further shows how PP relates to Epigenetics and offers a possible solution to the obesity crisis through four defined sections;
Background to Positive Psychology- Applied Positive Psychology and Positive Psychology Interventions (PP, APP & PPI)
Epigenetics – The study of Epigenetics affecting present and future generations – Genotypes to Phenotypes
Obesity – The Obesity Crisis and how Epigenetics and PPI’s can affect outcomes for present and future generations.
Positive Psychology Interventions (PPI’s) – To combat the obesity crisis
Finally implications and conclusions from the evidence are explored, along with onward looking possibilities for future research incorporating a multi-disciplinary focus.
Background to Positive Psychology, Applied Positive Psychology and Positive Psychology Interventions (PP, APP and PPI)
Positive Psychology emerged in its first wave in 1998 as an antitheses to ‘psychology as usual’ which mostly focused on identifying and correcting dysfunction as its core purpose. Ref. Psychological distress being deemed actionable if meeting categorised and listed criteria set out in the manual of dysfunction, or as it is more commonly termed the Diagnostic and Statistical Manual – DSM
Perhaps the inevitable consequence of focus on dysfunction, would eventually lead to the study of function as a natural progression of dyadic process addressed by Dr. Martin Seligman credited as the founder of modern day positive psychology ref. Dr Seligman and colleagues co-authored a positive focus manual designed to explore the possibilities of optimum function through Core Strengths and Virtues –CSV (Peterson & Seligman, 2004) which sought to counteract the dysfunction focus.
Positivity and living a good life was not however a new concept having connections to the earlier 20th century discipline of humanistic psychology (Resnick et al., 2001).
The term itself, Positive Psychology is credited to the Psychologist Abraham Harold Maslow best known for his contribution to modern psychology with the Hierarchy of Needs (Maslow, 1943)
The new PP pioneers included Martin Seligman with his focus on authentic happiness (2002), Ed Diener with a reputation in the field of subjective well-being (1984), Mihaly Csikszentmihalyi eschewing the virtues of flow (1988), Barbara Fredrickson with her focus on positive emotions (2001), and Sonja Lyubomirsky and her work on the genetic and environmental components of happiness (2008) to name a leading few.
However just as in other scientific disciplines discovery involves theory change – a continuous evolving process including observations, feedback, experiment, interpretation and re-interpretation of data which derive new results (Popper, 1963) thus PP had inevitably started to go through a similar process.
Positive psychology research and practice reached an era of criticising the very discipline as a whole, even questioning whether it had any validity or even a rationale to exist at all. (McNulty & Fincham, 2011).
The criticism levelled at PP had little effect on proponents such as Seligman who were driving forward and evolving the discipline with great enthusiasm into a worldwide movement. (ref)
Not all of the attention to the new discipline was flattering though, and some went even further to imply it could be detrimental to human life. (Ehrenreich, 2009) At an unfortunate time during which the USA increased involvement of its troops in foreign lands, Ehrenreich intonated PP interventions employed by the United States army were implicated in leading soldiers to their deaths. Buoyed up with what was termed false positivity and over estimation of their abilities a position which highlighted the value of ‘negative’ emotions such as fear.
Further opposing views came from English professor Eric Wilson who put the case for those who wished to remain ‘melancholics’ exploring this notion in his book . While he had no wish to romanticise clinical depression, the professor however argued for the inspirational motivational states that arise from melancholia. Worrying that they could be completely wiped out if we continue with the compulsion to treat every negative mood as ‘bad’. Further purporting that if such a state had prevailed historically we may never have been honoured with the works of such greats as Van Gogh, Keats or Beethoven. Wilson (2008)
Such considerations certainly make one appreciate just how complex, intertwined and multipronged are the workings of human emotions and their unique and subjective effects on the holder.
Getting to the middling point depends upon hitting both extremes of high and low and what emerges is a state that incorporates aspects of both. As an astute thinker put it – creating a ‘higher’ unity that transcends and yet preserves the truth of both extremes (Mills, 2000).
Later, evolving further after attracting much criticism and fierce debate PP came into full swing to answer, elaborate and explore how positive and negative emotions could impact and enrich the human condition. We might call this the ‘second wave’ of PP (Held, 2004). The focus of the second stage or PP 2.0 as it is often referred focuses firmly on empirically valid study and research (ref) with an applied rationale using positive psychology interventions (PPI’s)
PPI’s being defined as ‘empirically-validated interventions designed to promote wellbeing in a non-clinical population.’ (Lomas, Hefferon & Itai, 2014) However not to detract from their potential for clinical use it should be stated that PPI’s have been used with great success in treating mental illness. (Seligman et al, 2005)
To make a simile for the relationship between the traditional and the newest branch of psychology consider Newton’s 3rd Law of motion which states that when a body exerts a force on a second body an opposing force of equal magnitude but opposite direction results. (Newton, 1726)
Positive Psychology could be equated to a force of equal magnitude as that of psychology as usual, and as such their existence could actually be dependent upon each other. Or as physicist David Bohm states; ‘nothing simply surges up out of nothing without having antecedents that existed before’ (Bohm, 1959) It is therefore no surprise that the study of function arose out of the study of dysfunction, and will likely remain inextricably linked.
Epigenetics – The study of Epigenetics affecting present and future generations Genotypes to Phenotypes
Epi-genetics is a Greek term meaning ‘above’ or ‘on top of’ genes. (Carey, 2011) This fascinating subject is the study of how genes can be turned on or off through a control switch genes have been found to posses.
Epigenetic changes do not actually alter the genetic code, or as it is known the DNA sequence (genotype). Rather the epigenetic changes are like a switch that sit on top of the genome and affect how the cell reads that genetic code. (Spector, 2012) We cannot alter the sequence of our DNA however a wide variety of environmental factors affect the expression of how those genes are activated or inactivated. Gene expression is related to the chemical messengers (usually proteins) governing the cell which determine the behaviour of the cell – phenotype (Spector, 2012)
As the foetus grows in early development the majority of cell activity is governed from within the existing cells or adjacent cells. (Gidekel, et.al. 2002 In this crucial stage of development, the food the mother consumes plays a large part in the development of the epigenome. (Gidekel, et.al. 2002 However as well as nutrition having a large role to play, stress hormones also affect signals to the cells. (Gidekel, et.al. 2002) Which signifies the wider environment of the mother is already affecting the child’s development.
Post-natal development continues to shape epigenetic expression through wider environmental factors. (Carey, 2011) Physical activity, social interaction and nutritional elements continue to affect the individual by transmitting information from cell to cell. (Spector, 2012) It is these signals that direct intra cellular learning and physical growth. (Spector, 2012)
As the child grows the organs develop and most significantly the brain (Kolb, et.al., 1998). At a younger age neuro plasticity – the way in which brain matter volume increases or reduces and neural connections alter is at its height (Kolb, et.al., 1998). The young brain is very impressionable much more so than it will be as it matures.
The upside is that children and young people advance faster in cognitive processes however conversely the downside is heightened neural susceptibility to being impacted by adverse nurturing experiences and physical or psychological maltreatment. (ref)
Depending on learned experiences the cells go through Mitosis – cell growth and replacement, a lifelong process (Schwartz, 2012). The salient factor to consider is the the prudence of ensuring cells, especially brain cells acquire good information to lay the template for future neural growth and reorganisation. This neural-pruning takes place in childhood, puberty and throughout later life. (Naftali & Rodrigue 2006)
However not only does environmental influence affect neuro plasticity in the current functioning but can have far reaching implications for subsequent generations. (Carey, 2011)
As an example in practice; heritability of epigenetic factors has been explored in mice where the parental mice were trained to be fearful of a certain smell. Later their offspring, conceived long after the experiment ended, were found to have a heightened sensitivity and the same fearful reactions despite no previous olfactory exposure to the target odour. The gene involved was found to be unaltered in any way in its transmission to the later mice but the epigenetic markers on top of the gene were activated. (Callaway, 2013) Giving further weight to earlier studies which found as individuals develop, morphogens activate or silence genes in an epigenetically heritable fashion, giving cells a “memory” (Reik, 2007)
In a recent epigenetic obesity study it was found that the early environment of the child induces altered epigenetic regulation resulting in an altered phenotype. (Lillycrop & Bruge, 2011). The authors further noted the escalating rate of the incidence of obesity over the past 20 years can no longer be solely explained by purely genetic and adult lifestyle considerations.
Of further note “Plasticity – the capacity of organisms to change in response to varying conditions – is a wide topic however an understanding of plasticity is now recognised as being fundamental to an understanding of evolution” (Gissis and Jablonka)
From the evidence it would be reasonable to conclude the DNA strand of code (genotype) does not change or alter, however epigenetic activation/inactivation affect how the genes are expressed due to a range of environmental factors which shape the learning and expression of genes (phenotype) during the lifetime of the individual and in a heritable way which is passed on from generation to generation.
The obesity crisis and how Epigenetics and PPI’s affect outcomes for present and future generations.
What shall be termed in this discussion The Obesity Crisis has reached an all-time high with predictions that 60% of men, 50% of women and 25% of children will be obese by the year 2050 (Forsight, 2007)
In the western world where The Obesity Crisis is at its height food appears to be connected to emotions as well as nutrition, which is a crucial point when considering interventions that target causes (Ganley, 1989). We associate that ‘little treat’ as our reward for various achievements throughout the day or week. Emotional eating is a firmly accepted occurrence (ref) and most of us have at some time or another eaten because of entitlement, anxiety, depression or other emotions not in the least related to physical hunger.
Coupled with the fact that nowadays we have a much more sedentary culture than previous generations. (ref) Travelling by car door to door, sitting at computers for hours at a time and generally eating more calorie laden food while taking less exercise are all factors in an obesity crisis that could potentially bankrupt the health services. Modelled projections suggest that in the UK alone indirect costs could be as much as £27 billion by 2015 (Butland, Jebb & Kopelman, 2007)
Considering that being overweight is associated with low self-esteem and depression (Wiley-Blackwell. 2008) it would appear a good idea to tackle this peculiar myth that food makes us happy and instigate interventions to alter this awry perception.
Professor Kevin Fenton of PHE warned “Obesity is a complex issue that requires action at national, local, family and individual level. Everyone has a role to play in improving the health and wellbeing of the public and children in particular”
The rational for ensuring children are raised within an environment that includes positive and productive early experiences would appear to be firmly established by research (ref), although it is worth considering the wisdom of early intervention as a concept has been around for many years prior to this scientific stance. (Fenske, et.al., 1985)
A damaging way that children are often rewarded is with food or food related treats. A whole culture of food related to fun experiences has sprung up with themed restaurants that stress family time is centred around eating and promoting the concept that eating junk food is a fun and positive activity for the family to spend time participating in. (ref)
Long term self-satisfaction from doing tasks is the goal rather than instant food rewards. Being approved of and praised for effort raises children’s levels of self-esteem. (Dweck, 2007). Children who are verbally praised for trying hard (rather than for innate abilities) were more likely to have a go at tackling difficult tasks was an additional finding within the same study.
Obesity is not just about eating less and moving more, it is also about our emotional connections with food as we have lost touch with our inner selves. We have made lifestyles that have become the inheritance of our children who start their lives with predispositions we have epigenetically engineered for them. If we want them and their children to have a better inheritance we have to change the environmental influences that alter phenotypical expression.
PPI’s – Positive Psychology Interventions for The Obesity Crisis
Present obesity initiatives or Obesity as Usual focus on weight reduction and exercise (Aicken, Arai & Roberts, 2008). This symptomatic approach where the exercise does not produce anything or the diets fail to consider the emotional connections, has had little success if the rising figures and cost predictions discussed earlier are considered. From these earlier discussions there appears to be a rationale to tackle obesity at cognitive, emotional and physical levels and stages of development, starting prenatally. Interventions should be preventative and additionally have the capacity to be useful if children and adults are already or become overweight.
The intervention plan based on developing a community interaction strategy (appendix 1) is presented as a humble starting point which could be adapted and further developed for various communities.
Community based interventions could address present obesity, promote better physical and mental health and carry the potential for preventative and future epigenetic change. Community Participation Hours (CPH) credits offer an additional incentive for reduced taxes in recognition that those costs would be more than recouped through lower obesity, mental and physical health costs to government services.
Conclusions and Implications
Just as psychology as usual has been affected by the new breed of Positive Psychology, obesity as usual needs to give way to new thinking. The Obesity Crisis is not just about eating less and moving more but connected to a vast range of biological, genetic, epigenetic, lifestyle, physical, emotional and psychological processes that we have the ability to affect and change given effective environmental interventions.
From the evidence it would be reasonable to conclude that the main DNA strand of code (genotype) does not change or alter however a range of environmental factors shape the learning and gene expression (phenotype) in present and future generations.
Considering the findings there is a basis to consider how epigenetic expression gives an enormous amount of control, over ourselves and future generations. Adapting environmental influences can affect chemical reactions of proteins and the current expression of genes, as well as the heritable component of epigenetic phenotypes.
Changing behaviour and initiating PPI’s based around children and communities from a young age could alter epigenetic makeup and predisposition to develop obesity for their own lives and future generations.
The implications of these findings suggest future outcomes depend upon the cognitive, emotional and physical experiences people are exposed to across the whole lifespan from conception onwards which have the potential to shape future physical and psychological epigenetic component abilities, inabilities and predispositions of present and subsequent generations.
Onward Focus
Ante-natal care could include epigenetic counselling components for expectant families to stress the vulnerability of offspring to modification.
Future social policy could also be informed by the outcomes of pilot studies for community based programs such as those outlined in the PPI section of this paper (Appendix 1) which have the potential to produce a significant amount of actionable information.
APPENDIX 1 Positive Psychology Community Plan Interventions
Level Location Initiatives/Interventions Benefits
National Schools
Workplaces
Health Service
Government Self-sufficiency training and productive food growing in a dedicated school garden that every school would have
Exercise programs / healthy canteens
Antenatal care dedicated to lifestyle/epigenetic knowledge and responsibility
GP’s encouraging anti-obesity initiatives/ mandatory child obesity check-ups
Credits awarded for Community Participation Hours (CPH) Children growing up with self-sufficiency awareness/ thrift resourcefulness/seasonal knowledge / Peer support and bonding / meaningful work
Fitter happier workforce less time off
Grassroots change for future generations / better choices more awareness / stopping the cycle
Monitoring and encouraging the community / point of reference of changes in nations health
Tax incentives for those who participate in certain amounts of CPH with initiatives for both individuals and companies /extra benefits for the unemployed who participate.
Local Community Spaces
Food Growing Allotments / Community Greenspaces maintained and cared for by the community.
Self –sufficiency co-op centres run by the community e.g. Making eco-bricks from shredding recycling materials to heat schools/centres instead of fossil fuels/ Recycling re-using and repairing focus Community spirit less vandalism more care for own spaces
Community self-sufficiency and sustainability / saving money
Local produce less pollution
Community Appreciation
Comradery / developing organisation skills
No barriers to participation
all fitness levels / economic status open to participate
Family Home
Participating in running and maintaining the local and national initiatives using the produce from the community spaces in healthy cooking/ storing/freezing/ redistributing to others. Making, using and distributing the eco bricks. Children given chores at home and for the community spaces to ensure at least an hour of (CPH) activity every day. Better mental/physical health
More community focus
Less money spent on food
Less spent on entertainment
Empathy development
Satisfaction
Feeling needed and useful
Appreciation
Building resilience
Better future health for now and later epigenetic change
Individual Home More active community participation less sedentary and alone time more people time. Practicing Meditation and Mindfulness
More bikes less cars
Better physical and mental health
Community spirit and empathy development / sense of achievement/ developing optimism/ Self-awareness and spiritual development / encouraging positivity/ Less pollution
Collective Responsibility Community Visiting the sick in hospices hospitals and community
Visiting the elderly and those who are alone and in need or housebound. Offering lifts and community transport More community awareness /caring / empathy development / awareness of mortality / sharing knowledge and wisdom of the aged / joy of giving / developing self-respect/ appreciation
Less reliance on public health services
References
Aicken C, Arai L, Roberts H (2008) Schemes to promote healthy weight among obese and
overweight children in England. Report. London: EPPI-Centre, Social Science Research Unit, Institute of Education, University of London.
Aitkin, M., Anderson, D., & Hintz, J. (1981). Statistical modelling of data on teaching styles. Journal of the
Royal Statistical Society, 144, 419-461.
APA, (2015). Parenting and teaching: What’s the connection in our classrooms?. Retrieved 3 January 2015,
from http://www.apa.org/ed/precollege/ptn/2013/09/parenting-teaching.aspx
Biffle, C., & Plato.,. (2001). A guided tour of five works by Plato. Mountain View, Calif.: Mayfield Pub. Co.
Bohm, D., (1959). Significance of electromagnetic potentials in the quantum theory Y. Aharonov, D. Bohm –
Physical Review, 1959
Butland B, Jebb S, Kopelman P, et al., (2007) Tackling obesities: future choices – project
report (2nd Ed). London: Foresight Programme of the Government Office for Science, 2007.
Callaway, E. (2013). Fearful memories haunt mouse descendants. Nature. doi:10.1038/nature.2013.14272
Carey N. (2011): Epigenetics revolution: How modern biology is rewriting our understanding of genetics,
disease and inheritance. Icon Books, London.
Csikszentmihalyi, M., Selega, I., eds (1988). Optimal Experience: Psychological studies of flow in
consciousness, Cambridge: Cambridge University Press. ISBN 0-521-34288-0
Clonan, S. M., Chafouleas, S. M., McDougal, J. L. and Riley-Tillman, T. C. (2004), Positive psychology goes
to school: Are we there yet? Psychol. Schs., 41: 101–110. doi: 10.1002/pits.1014
Daglas, P., (2006) Effects of self-esteem intervention programme on school age children
Pediatric Nursing, 32 (4) (2006), pp. 341–348
Diener, E. (1984). Subjective well-being. Psychological Bulletin, 95, 542-575.
Dweck, C.S. (2007) “The Perils and Promises of Praise,” Educational Leadership, Oct 2007 Vol 65, No. 2.
Eckersley, R. (2010). Commentary on Trzesniewski and Donnellan: A transdisciplinary perspective on young
people’s well-being.Perspectives on Psychological Science, 5, 76-80.
Edison, T., (1898) quoted in the Ladies Home Journal
Ehrenreich, B., (2009) Bright-sided: How the Relentless Promotion of Positive Thinking has
undermined America. MacMillan
Faitz, L.M., (2012) ‘Individual Reactions to Adversity: An Exploration of the Relationship Between Self-
Esteem, Resilience, and Locus of Control’ McKendree University Online Journal of Undergraduate Research. Issue 19 – winter 2012.
Fenske, E. C., Zalenski, S., Krantz, P. J., & McClannahan, L. E. (1985). Age at
intervention and trearment outcome for autistic children in a comprehensive
intervention program. Analysis and Intervention in Developmental Disabilities, 5, 49-
58.
Fordyce, Michael, W., (1983). Program to increase happiness: Further Studies Journal of Counselling
Psychology, Vol 30(4), Oct 1983, 483-498
Foresight- (2007) Tackling Obesities – Future Choices 2007 London: NICE
Fredrickson, BL (2001). “The Role of Positive Emotions in Positive Psychology”. American
Psychologist 56 (3): 218–226. doi:10.1037/0003-066X.56.3.218. PMC 3122271.PMID 11315248.
Ganley, R.M., (1989) Emotion and eating in obesity: A review of the literature. International Journal of Eating
Disorders 1989;8:8343
Gidekel S, Bergman Y. (2002). “A unique developmental pattern of Oct3/4 DNA methylation is controlled by a
cis-demodification element”. Journal of Biological Chemistry 277: 34521–34530.doi:10.1074/jbc.m203338200.
Gissis S.B., Jablonka E., (2011) Preface. In Gissis SB, Jablonka E, editors. Transformations of Lamarckism:
From subtle fluids to molecular biology. Cambridge, MA: The MIT Press 2011pxi-xiv.
Greenberger, E., Lessard, J., Chen, C., & Farruggia, S.P. (2008). Self-entitled college students: Contributions
of personality, parenting, and motivational factors. Journal of Youth and Adolescence, 37, 1193-1204.
Judge, T. A.; Locke, E. A.; Durham, C. C. (1997). “The dispositional causes of job satisfaction: A core
evaluations approach”. Research in Organizational Behavior 19: 151–188.
Kolb, Bryan; Whishaw, Ian Q. (1998). “BRAIN PLASTICITY AND BEHAVIOR”. Annual Review of
Psychology 49 (1): 43–64. doi:10.1146/annurev.psych.49.1.43.PMID 9496621.
Krieger, R. (2010) top Walking on Eggshells: Taking Your Life Back When Someone You Care About Has
Borderline Personality Disorder, Second Edition( (New Harbinger, 2010)
Live Happy Magazine,. (2015). Positive Psychology Timeline. Retrieved 5 January 2015, from
http://www.livehappy.com/science/resources/positive-psychology-timeline
Lerner,R.M,, Overton, W.F., (2013) Epigenetics, evolution, and embodiment: On the
conceptual vacuity of evolutionary psychology. OA Genetics 2013 Jun 01;1(1):6
Lillycrop, K.A., & Burdge, G.C., (2011) International Journal of Obesity London.
Jan;35(1):72-83. doi: 10.1038/ijo.2010.122. Epub 2010 Jun 15
Lomas, T., Hefferon, K., Ivtzan, I., (2014) ‘The LIFE Model: A Meta-Theoretical
Conceptual Map for Applied Positive Psychology’, Journal of Happiness Studies (doi:10.1007/s10902-014-9563-y).
Lomas,T., (Forthcoming). The dialects of emotion in I.Ivtzan, T. Lomas, K.Hefferon & P. Worth (Eds),
Challenging Positive Psychology: Embracing the Dark Side of Life, London: Routledge.
Lyubomirsky, S. (2008). The how of happiness: A scientific approach to getting the life you want. New York:
Penguin Press
.
Maslow, A. (1943). A theory of human motivation. Psychological Review, 50(4), 370-396.
doi:10.1037/h0054346
Maslow, A. (1970). Motivation and personality. New York: Harper & Row
May, H. (2000). On Socrates. Australia: Wadsworth/Thomson Learning
Naftali, R., Rodrigue, K.M. (2006) “Differential aging of the brain: Patterns, cognitive correlates and
modifiers”. Neuroscience & Biobehavioral Reviews 30 (6): 730 748.
McNulty, J. K., & Fincham, F. D. (2011). Beyond positive psychology? Toward a contextual view of
psychological processes and well-being. American Psychologist, 67(2), 101-110.
New Economics Foundation (2003) A Well-being Manifesto for a Flourishing Society. London, UK: NEF
Newton, I., (1726) Philosophiae Naturalis Principia Mathematica: the Third edition (1726) with variant
readings, assembled and ed. by Alexandre Koyré and I Bernard Cohen with the assistance of Anne Whitman (Cambridge, MA, 1972, Harvard UP)
O’Hear, A. (2004). Modern moral philosophy. Cambridge, UK: Cambridge University Press.
Peterson, C., & Vaidya, R. S. (2003). Optimism as virtue and vice. In E. C. Chang & L. J.
Sanna (Eds.), Virtue, Vice, and Personality: The Complexity of Behaviour (pp. 23-27).
Washington, DC: American Psychological Association.
Pigliucc, M., Müller, G.B.,(2010) Elements of an extended evolutionary synthesis. In
Pigliucci M, Mueller GB, editors. Evolution – the extended synthesis. Cambridge, MA: MIT Press 2010p3-17.
Popper, Karl (1963), Conjectures and Refutations, Routledge and Kegan Paul, London, UK. Reprinted
in Theodore Schick (ed., 2000), Readings in the Philosophy of Science, Mayfield Publishing Company, Mountain View, Calif.
Reik, W., (May 2007). “Stability and flexibility of epigenetic gene regulation in mammalian
development”. Nature 447 (7143): 425 32. Bibcode:2007Natur.447..425R.doi:10.1038/nature05918. PMID 17522676.
Reuters, (Jun 18, 2009) First World Congress on Positive Psychology Kicks Off Today With Talks by
Two of the Worlds Most Renowned Psychologists. World Reuters News Feed.
Resnick, S., Warmoth, A., & Serlin, I. A. (2001). The humanistic psychology and positive
psychology connection: Implications for psychotherapy. Journal of Humanistic
Psychology, 41(1), 73-101.
Roosevelt, M. (2009, February 18). Student expectations seen as causing grade disputes. The New York Times,
p. A15.
Rotter, J. (1966). Generalized expectancies for internal versus external control of reinforcements. Psychological
Monographs, 80, Whole No. 609
Rutter, M. (2008). “Developing concepts in developmental psychopathology”, pp. 3–22 in J.J. Hudziak (ed.),
Developmental psychopathology and wellness: Genetic and environmental influences. Washington, DC: American Psychiatric Publishing.
Seligman, M.E.P., (1972). Learned Helplessness Annual Review of Medicine Vol. 23: 407-412 (Volume
publication date February 1972) DOI: 10.1146/annurev.me.23.020172.002203
Scofield, C., & Rikkers, D. (2003). The Scofield Study Bible. New York: Oxford University Press.
Schwartz, G. (2012). Growth, Development, and Life History throughout the Evolution of Homo. Current
Anthropology, 53(S6), S395-S408. doi:10.1086/667591
Seligman, M. E. P., Rashid, T., & Parks, A. C. (2006). Positive psychotherapy. American Psychologist, 61(8), 774-788.
.
Seligman, M. E. P., Steen, T. A., Park, N., & Peterson, C. (2005). Positive psychology
progress: Empirical validation of interventions. American Psychologist, 60, 410–421.
Spector, T, (2012). Identically Different: Why You Can Change Your Genes. London: Weidenfeld & Nicolson
Trzesniewski, K.H., & Donnellan, M.B. (2010). Rethinking “Generation Me”: A study of cohort effects from
1976–2006.Perspectives on Psychological Science, 5, 58-75.
Twenge, J.M. (2006). Generation Me: Why today’s young Americans are more confident, assertive, entitled —
and more miserable than ever before. New York: Free Press.
Twenge, J.M. (2013). Teaching Generation Me. Teaching of Psychology, 40, 66-69.
Twenge, J.M., & Campbell, W.K. (2010). Birth cohort differences in the monitoring of the future dataset and
elsewhere: Further evidence for Generation meme — Commentary on Trzesniewski & Donnellan. Perspectives on Psychological Science, 5, 81-88.
Wallace, M., Christopher, B., Zeigler-Hill, V., and Green, B. (2012). Locus of Control as a Contributing Factor
in the Relation Between Self-Perception and Adolescent Aggression. Aggressive Behavior, 38(1), 213-221.
Wilson, E. G., (2008). Against Happiness: In Praise of Melancholy. New York, NY: Sarah Crighton Books.
Wiley-Blackwell. (2008) “Obesity And Depression May Be Linked.” ScienceDaily.
ScienceDaily, 6 June 2008. www.sciencedaily.com/releases/2008/06/080602152913.htm