Metacognition (Part 2): What Makes Us Truly Human? A Literature Review

original robot picTo learn is to create: Educational robotics are a very recent trend that requires children and adolescents to plan, reason, experiment, create, play and learn from failure. In the process, they acquire and apply new knowledge. As in most such technology-based scenarios, students learn in teams. Photograph by Alain Herzog, 2015

The path of least resistance and least trouble is a mental rut already made. It requires troublesome work to undertake the alteration of old beliefs.

John Dewey

What makes us truly human? Part 1 of this series (‘What or how we think is not quite as important as how we can govern ourselves’) outlined the significance of metacognition on the individual and social level. It was concluded that the freedom to develop alternative solutions to a problem and to become self-aware of one’s own as well as others intentions, perspectives, feelings and interests constitute key competencies of the human condition. Without such freedom, our mind would simply follow environmental stimuli or tradition and we would barely be capable of developing a more complex and rewarding lifeworld.

The following review investigates the deeper structure of metacognition. It is divided into two sections. Section 1 provides an overview of leading concepts that investigate individual and social metacognition (ISM). Section 2 reviews the suitability of various theoretical frameworks in order to propose a unifying approach of how to measure metacognition in the context of autonomous (intrinsic) versus heteronomous (extrinsic) regulation.

1. The dimensionality of individual and social metacognition

Individual Metacognition: Self-Knowledge and Behavioral Control

The first formal model of individual metacognition was developed by John Flavell (Flavell, 1979, 1981) who was influenced by the constructivist psychology of Jean Piaget (Flavell, 1963). Flavell (1979) defined metacognition broadly as a person’s self-knowledge and regulation over her own cognition, an overarching concept that is shared in literature (Brown, 1987; Flavell, 1976, 1979; Kuhn & Dean, 2004; Martinez, 2006; Paris & Winograd, 1990; Schraw & Moshman, 1995; Schraw et al., 2006).  Metacognition is accompanied by metacognitive experiences such as the feeling of difficulty (or ease of learning), the experience of self-efficacy, affective states dealing with uncertainty and task motivation (Efklides, 2006, 2009, 2014; Flavell, 1981; Kleitman & Moscrop, 2010; Schneider, 2008; Zimmerman, 2008). Metacognitive experiences have been identified to play a critical role in self-enhancement motivation (Jiang & Kleitman, 2015) to support self-regulated learning (Boekaerts & Corno, 2005; Boekaerts & Niemivirta, 2000; Dweck, 1998).

Metacognitive knowledge generally refers to the reflective knowledge that people have about their information processing skills which entail the knowledge of tasks, task complexity and the knowledge of strategies on how to cope with tasks. Corresponding metacognitive regulation describes the related executive skills of cognitive monitoring and self-regulation associated with metacognitive knowledge (Schraw et al., 2006; Schneider, 2008). Flavell’s original blueprint has since been extended considerably by other researchers.

Adding to the definition of metacognitive knowledge, several authors (Cross & Paris, 1988; Kuhn & Dean, 2004; Schraw et al., 2006) have identified declarative, procedural and conditional knowledge as its central components. Declarative knowledge refers to a learner’s self-knowledge of resources and abilities. Procedural knowledge refers to the knowledge of the purpose and the processes involved to solve problems and to self-regulate tasks (Metcalfe & Shimamura, 1994; Nelson, 1994, 1996) while conditional knowledge refers to knowing the conditions under which knowledge can be generated, transferred and applied (Schraw & Dennison, 1994).

The concept of metacognitive regulation has likewise been expanded upon and includes the planning and critical evaluation of cognitive tasks and goals (Brown, 1987; Dunlosky & Metcalfe, 2009; Cross & Paris, 1988; Martinez, 2006; Paris &Winograd, 1990; Schraw et al., 2006; Schraw & Moshman, 1995; Whitebread et al., 2009). Metacognitive planning entails the abilities of forethought (Pintrich, 2000), for example by goal setting and resource allocation, while Schraw & Moshman (1995) and Schraw & Dennison (1994) added debugging strategies to correct for comprehension and performance errors, information management strategies to process information more efficiently and comprehension monitoring to allow for the self-assessment of one’s learning.

Metacognitive regulation has been further segmented into (a) Cognitive monitoring, which refers to making self-aware judgments about one’s learning. (b) Metacognitive planning which, as outlined above, refers to the evaluation and employment of most efficient resources and strategies (Cross & Paris, 1988; Li et al., 2015; Schraw et al., 2006; Whitebread et al., 2009) and (c) Metacognitive evaluation, which refers to the ability of making metacognitive judgments and formulating monitored interpretations (Dunlosky& Metcalfe, 2009; Pintrich, 2000; Schraw & Moshman, 1995; Wang, 2014).

Formulating a more holistic approach, Pressley, Borkowski, and Schneider (1989) have proposed the ‘Good Information Processing Model’ which also takes into consideration the elements of prior knowledge about the world, motivational orientation and the ease of employing successful strategies automatically. This model was later extended to include metacognitive self-regulation skills (Efklides, 2001; Schunk & Zimmerman, 1998, Schneider, 2008). The level of prior knowledge plays a large role in pedagogy as it defines the scope of a learner’s inner resources such as coherent concepts and internalised ideas.

Much of current research on metacognition deals predominantly with empowering student learners such as in literacy, reading and comprehension (Baker, 2008; Israel et al., 2005; Leopold & Leutner, 2015), developing self-efficacy (Aydin, 2006), improving problem-solving (Cornoldi et al, 2015; Wismath & Orr, 2015), essay writing (Surat et al., 2014) and mathematics (Desoete & Veenman, 2006; Özcan & Erktin, 2015; Kleden, 2015). Other studies have focused on peripheral topics such as linking metacognition to worrying and sleep (Thielsch, Andor, &Ehring, 2015; Thielsch et al., 2015) or consumer knowledge discrimination (Pillai et al., 2015). Not much research has been conducted in areas such as the workplace, organisational decision-making, culture or politics.


Picture (MIT): Prof. Tommi Jaakkola during a class in AI “Introduction to Machine Learning”. The more complex a society, the more relevant becomes cognitive and metacognitive regulation

As part of self-regulated learning, metacognition has also been linked to critical thinking skills (Bowell & Kemp, 2010; Dwyer et al., 2014; Felton & Kuhn, 2007; Halpern, 1998; Ku & Ho, 2010; Kuhn, 1999; Magno, 2010; Mayer & Goodchild, 1990; Olson & Astington, 1993; Schroyens, 2005) since metacognition is self-correcting and refers to the epistemological question ‘What do I know and how do I know it?’ (Kuhn, 1999, p. 18).Critical thinking skills involve executive functions for difficult cognitive tasks, such as recognizing assumptions, making inferences and deductions, formulating interpretations and evaluating arguments (Magno, 2010). Despite general agreement on the overall construct of metacognition, Kuhn & Dean (2004) pointed out that there is e.g., a large divide between psychological researchers, emphasizing on objective standards, and practitioners who expect students to be empowered to contribute to a democratic society. Both standpoints beg reconciliation. An overview of the general taxonomy of individual metacognition is summarized in Figure 1.

Figure 1: Systematic overview on the concept of  individual metacognition by the author (click to enlarge)

Social Metacognition: The Awareness of Others

No human life, not even the life of the hermit in nature’s wilderness, is possible without a world which directly or indirectly testifies to the presence of other human beings.

Hannah Arendt, The Human Condition

The official advent of social metacognition in social psychology was marked by a publication of an edited volume on metacognition by Dardenne, Lories & Yzerbyt (1998) which connected topics that are of particular interest to social psychologists, such as relating feeling-of-knowing judgments and theories about the social influence on memory with topics such as stereotyping, prejudice and social bias correction.  Since then, social metacognition has been established as an essential topic in social psychology (Bless & Forgas, 2000; Mischel, 1998).

One of the key issues has been, ever since, differentiating social metacognition from individual metacognition. Briñol (2012) argued that metacognition is primarily defined as thinking about one’s own (vs. others’) thinking, since primary thought is causally more efficient if it appears in one’s own head. Social metacognition is represented for Briñol in many ways, for example as an individual’s mentalizing about social objects (e.g., the perception of family and relationships), thoughts shared by a community (thoughts about others’ thoughts) or thoughts communicated to others.

Briñol rejected the proposal by Jost and colleagues (1998) who called for an expansionist approach of social metacognition on the grounds that the true agent of mentalization is still the individual subject. In this proposal the authors called for the inclusion of (a) mentalizing about other people’s cognition, (b) momentary convictions, such as ‘the feeling of knowing’ (Nelson & Nahrens, 1994) and (c) descriptive general beliefs of how the mind works, such as beliefs about intelligence (Dweck, 2013) as well as normative beliefs of how the mind should or should not work, such as deferring to make stereotype judgments about others (Yzerbyt et al., 1994).

Jost and colleagues (1998,  p. 140) argued, with experimental evidence from studies on familiarity heuristics, that ‘fleeting feelings’ are often guided by metacognitive states (Banaji & Greenwald, 1995; Begg, Armour & Kerr, 1985; Jacoby et al., 1989; Metcalfe; Strack & Bless, 1994). The authors argued that self-concepts such as beliefs about self-efficacy (Bandura, 1991; Ferrari, 1996) or the nature of intelligence (Dweck, 2013) are modelled via social learning processes and thus need to be included in social metacognition.

The opposing positions of Briñol et al. (2012) and Jost et al. (1998) can be reconciled by putting into perspective that social metacognition plays out on a gradient scale between implicit, automated processes and explicit, reflected mental processes. In this light, Schraw & Moshman (1995) proposed a taxonomy defining (a) tacit (b) explicit-informal and (c) explicit-formal metacognitive theories. Tacit theories (a) are acquired, constructed and applied without one’s knowledge. For example, a teacher’s epistemological assumption of how adults learn describes his tacit, implicit theory about students’ learning and decision-making (Kagan, 1992; Sternberg & Caruso, 1985). Explicit-informal theories (b) imply a subject’s awareness and knowledge of some of the mental content, while the rudimentary framework still lacks conscious justification of beliefs and their underlying assumptions.   On the level of explicit-informal theories people reflect purposefully and systematically on their actions and modify their future thinking and performance (Kuhn et al., 1992), differentiating between empirical and formal content (Hergenhahn & Olson, 1993). Finally, in explicit-formal theories (c) people become fully aware of their mental states as demonstrated, e.g., in Problem-based Learning where tutors facilitate metacognitive reasoning by asking group-members to provide arguments for their assumptions, beliefs and propositions (Barrows, 1992; Barrows & Wee, 2007).

Another approach to frame the multi-dimensionality of social metacognition, to pick up on Briñol’s argument of personal mental efficacy, is to differentiate how social metacognition is causally evoked by individual, social and environmental input. Kim and colleagues (2013) asked about the eliciting source of metacognition and propose a dual-agent (individual and social) organization of social metacognition. The authors argued that a single individualistic or social perspective by itself cannot sufficiently explain e.g., how learners with weak metacognitive skills can overcome temporary failures (Kim et al., 2013). Based on the concept of socially shared metacognition (Iiskala et al., 2011) and regulation within groups (Vauras et al., 2003) they concluded that the social level acts as an integrated agent in the form of consensual, participatory goal setting and collective planning. The learning environment evokes, as a separate layer, social metacognition by framing problems of different task complexity and conceptual demand. Individual metacognitive reasoning is for the authors causally defined as ‘due to oneself’ while social-level reasoning is defined ‘due to others’ (Kim et al., 2013, p. 388).

A neglected field of research is the relationship between empathy and social metacognition. The underlying question is how can we be motivated to take the plight of others into perspective if there is no prior emotional identification with the other, this is if we cannot recognize the other as an equal human being despite particular differences. The central role of empathy in combination with social metacognition is however fully recognized in Clinical Science (Eichbaum, 2014: Stansfield et al., 2015).

2. The suitability of theoretical frameworks to measure psychological motivations

If the goal of the research is to measure the entire spectrum of autonomous versus (competing) heteronomous types of regulation, few psychological frameworks offer a useful conceptual base. For example, the Theory of Planned Behavior (Ajzen, 1991, 2002) works under the assumption of individual, goal-directed behavior based on a person’s attitude, subjective norm, perceived behavioral control and individual intentionality. Like most rational-choice theories, the approach does not take into consideration heteronomous factors such as the influence of social habits, social milieu and interaction effects involving cultural context, social norms or group influence (Manstead, 2011).

On the other end of the spectrum, Social Identity Theory (SIT) (Taifel & Turner, 1979) works under the assumption that it is one’s group association that creates a sense of belonging and creates self-esteem, honour, pride and identity. SIT defines the subsequent processes that create social identity as (a) social categorization, where people categorize and define themselves and others in relation to each other, (b) social identification, where people adopt the identity of their new ingroup and (c) social comparison, where one’s ingroup is compared against outgroups, evoking judgments about the other groups’ worthiness as well as one’s own. SIT does conceptually not account for individual reasoning to transcend identities beyond group affiliation.

Self-determination Theory (SDT) (Deci & Ryan, 2012; Ryan et al., 2012), by comparison, takes as a motivational theory the entire spectrum of intrinsic and extrinsic types of motivation into account. It is argued that high-quality forms of motivation support the human needs for autonomy, competence and relatedness (Deci & Ryan, 2000; Ryan, 1995) while social context and cultural factors may even undermine motivation and volition. SDT is empirically well supported across disciplines (Deci et al., 1999; Chircov et al., 2003; Guntert, 2015; Hagger et al., 2015; Masden et al., 2014; Ng et al., 2012; Ryan et al., 2006; Van Berghe et al., 2014; Webb et al., 2013) and has demonstrated cross-cultural validity and reliability (Gagné et al., 2014; Grouzet et al., 2005; Sheldon et al., 2009; Soenens, 2012; Vlachopoulos et al., 2013; Zhou & Deci, 2009). SDT differentiates between five basic types of self-regulation (Ryan et al., 2012, p. 221-223) which shall be briefly described in relation to sociocultural context.

(1) Externally motivated and control-dependent behavior is characterized by the regulation by external rewards and punishments (Skinner, 1953) which exclude the Self. Beyond physical conditioning, rewards and punishments are also represented by peoples’ weighing between payoffs versus costs for complying with social norms (Sherif, 1935; Asch, 1951; Milgram, 1963). Hedonic adaptation (Diener et al., 2009; Kahneman et al., 1999), for example, can be regarded as a result of external motivation.

(2) Introjected regulation includes mental models that have been partially internalized by the self. In this case, the motivation for behavior is governed by the avoidance of shame and guilt or providing for socialized self-esteem rewards (Beer, 2014; James & Amato, 2013; Walker & Bright, 2009) such as in the honor cultures of the Mediterranean and the Middle-East.  Introjected regulation is also facilitated by inferences provided by common sense – (Heider, 2013) and folk psychology (Hutto & Ratcliffe, 2007; Kelley, 1992; Kruglanski et al. 2010) which largely supports culturally-shared, naïve assumptions “how people think they think about the social world” (Wegner & Vallacher, 1981, p. 226). On the other hand, loss of honor is typically followed by feelings of shame, feeling disrespected, disempowered and can be responded with aggression and violence.

(3) Identified regulation (social norm regulation) entails that people identify with their enactment of behavior and assume responsibility for their actions and they relate internalized social norms and values to reflected personal consequences for enacting them. Underlying social norms function on this level as injunctive norms (Cialdini and Trost, 2011), an intricate system of reciprocal expectations that society formulates towards the individual and, in return, expectations of the individual to how others should behave (Bicchieri, 2006).

(4) External integrated regulation describes a type of motivation where people do not only reflect upon personal and social norms, values and identifications, but they bring into congruence the claims and perspectives of others as the basis for cooperation. The causation of such reflective thought due to others is a hallmark of social metacognition (Kim et al., 2013).

(5) Intrinsic motivation implies that a person acts according to his or her personal aspirations. Behavior is initiated because it is experienced as personally enriching and engaging, independent of external stimuli. Intrinsic motivation entails the ability to resist habitual responding and to base decision-making on motivating values which are not a function of anxiety, defense and conditioned response. People seek to proactively develop positive social relations, environmental mastery, self-acceptance, personal growth, autonomy and purpose in life (Ryff, 1989; Kállay & Rus, 2014; Li, 2014) by free personal choice (Deci, 1971, 1975).

To this extent, intrinsic motivation is linked to individual metacognition for developing goal-directed behavior via mental strategies (Coutinho & Neuman, 2008; Ee et al., 2009; Gollwitzer & Schaal, 1998), while monitoring and controlling for adverse environmental influences that may frustrate, inhibit or prevent individual development (Vansteenkiste & Ryan, 2013).

From the perspective of SDT, ISM can be conclusively understood as forms of external integrated and intrinsic regulation. Heteronomous forms of regulation, by contrast, are usually encoded as folk- and cultural beliefs (introjected regulation), social norms and conventions (identified regulation) as well as hedonic well-being (both on an individual and social level with others). This conceptual approach entails a less polarized concept since in everyday life peoples’ lives are ruled by more complex types of motivation that combine individual and collective motives. As Chirkov and colleagues noted, “Because autonomy concerns volition, persons who are strongly connected with others often function with those others’ interests in mind. Put differently, if others are integrated within oneself doing for or conforming with those others could be fully volitional.” (Chirkov et al., 2003, p.103).


Picture: Instead of looking for solutions by respecting and integrating the perspective of others, modern societies often behave like tribes. Photo from an indigenous protest in Brazil during the UN Rio+20 summit. Source: KeystoneUSA-ZUMA / Rex Features

Conclusion: What makes us truly human?

In terms of research approaches, what appears of interest are not necessarily all possible forms of human motivation but those that are most relevant to generate specific outcomes. Since we are interested to empower human agency on all levels, we need to be aware of motivations compromising individual and social freedom and autonomy. In this light, the institutional embeddedness of metacognitive practices is of particular interest here, both in terms of the internal democratic management of organisations as well as developing socially inclusive services and sustainable design for clients. As pointed out in Part I of this series, the connection between empathy, social metacognition and the development of ethical concepts has not yet been fully investigated and lacks empirical research.

Self-awareness, self-regulation, forethought, logical reasoning, creativity, empathy, perspective-taking and the mindfulness of others are some of the key features that make us truly human. We have just begun to grasp the basic grammar of human agency.


Due to the long list, all references to Part 1 and Part 2 of this series are listed as PDF here Literature Review, References Joana Kompa.

On Aggression between Groups

A conceptual Postscriptum to ‘Is Thailand heading Towards a Failed Nation?


Dear Readers,

for the May Issue of ‘Live Encounters’ I have published an article with the title ‘Is Thailand heading Towards a Failed Nation?’ which can be found here. You can also locate it in the magazine’s PDF version. I found the topic exciting enough to add the post-scriptum below. Special thanks go to Mark Ulyseas for inviting me as an author.

Ingroup favouritism and outgroup derogation (Brewer, 1999) are obvious in the Thai conflict and appear typical of the behavior of competing groups. Social Identity Theory (Taifel, 1974) provides arguably the best theoretical framework to investigate the political divide since rural populations not only seek status equality, but also seek to find a new social identity as a suppressed majority group. There are a few new issues to consider as well.

1. In a Global Environment the Dynamics of Groups Keep Changing

The first issue is that traditional motivations of group-formation such as safety, shelter, social verification of self-esteem, the creation of local identity (Tajifel, 1974, Tajifel & Turner, 1986, Haslam et al., 2010, Haslam et al., 1996) or protection from nature and competing groups are nowadays extended to overlapping regional and global groups that manage the division of labour. The fact that we are, as Aristotle put it, Zoon Politikon, political animals (‘Lifeforms of the Polis’) is a given. Our lives naturally scaffold around our families, work-and study places and culture. To satisfy the human needs of Maslow’s pyramid we have no choice but to organize social orders. However, compared to more static traditional groups, global and international organizations start dominating life for most populations while such groups keep changing their make-up and frame of reference. New economic group-motivations generally foster collaboration and cooperation rather than rivalry. We could argue with Uri Bronfenbrenner that groups never exist in isolation and form along ecological systems (Bronfenbrenner, 1979). This may explain the conflict of interest between urban and rural populations.

In Thailand’s case the two rivaling groups, the UDD and PDRC, battle out their antagonisms at the expense of the social, political and economic stability of their nation. The self-categorization as ‘red’- or ‘yellow-shirts’ follows par excellence Self-Categorization Theory (Haslam et al., 1996). The inevitable conflict leads to an alienation between democratic institutions internally and to isolation by regional and international organizations externally as they withdraw from long-term investments and planning. Thailand has lost the power of ‘we’ and refocusing on superseding goals or collaboration, what most social psychologist may be tempted to suggest (Dovido et al., 2009, p.5), is unlikely to work in such aggravated atmosphere.

Traditional group formations based on e.g., ethnocentrism are equally fighting a losing battle in an increasingly networked world where groups influence each other, diversify and subdivide. In the Thai case study it is the nationalism on both sides, at times with xenophobic undertones, which prevents reasoning beyond the country’s borders. Even the pending integration of ASEAN for example and its very real ramifications for Thailand (creating a regional job market, competition between education systems and a united economic zone) are absent from public debate, not to talk about Thailand’s international dependencies.  The political divide appears to be framed as an introspective problem ‘by Thais for Thais’. The strength of my example of Suporn Attawong setting up a Thai militia in the North remains to be seen since there are divided reports that the government, facing potential impeachment, may not be sticking out their heads for Suporn in this delicate moment of time. The example of previous militia recruitment as under Seh Deng would have been perhaps more adequate. The fact that there even exists a recent ‘Thai history of militia recruitment’ supports powerfully the argument of violence permeating civil society. Every narrative is evidence.

The hijacking of groups by suitable authoritarian personalities such as Thaksin Shinawatra (Adorn, Frenkel-Brunswik & Levinson, 1950) follows compatible patterns:  in order to maintain a group’s superior self-esteem against all rational argument, group leaders need to be aggressive, without compromise and need to demonstrate toughness while demanding unquestioned loyalty and submission in return. Group conformity and the authoritarian personalities of leaders feed on a reciprocally beneficial relationship. Looking at groups without accounting for the salient beliefs, needs and motivations that drive participants to apparent group-consensus makes little sense in social psychology. Psychoanalytical motives such as representations of power struggles by parental figures appear likewise as valid interpretation.

2. People are embedded in Ethics of Responsibility

The second argument states that people are rational agents. Groups are, like individuals, responsible and accountable for their behavior and actions. Ethics are an integral part of social interaction. This touches issues of rights, duties and reciprocal obligations, shared values, norms and responsibilities, the fairness of contracts as well as the inclusion of superordinate, meta-contextual goals (Gaertner et al., 1990). Without standards of what can be expected in terms of a group’s communicative and ethical competence any performance-measurement and assessment in situ would render arbitrary. Including ethics between groups such as, e.g., measuring a group’s intercultural competence also entails that the observer has to define her own positioning during observation and has to openly declare the interest and purpose of research. Applied Social Psychology is thus a demanding task. Not only do we need to ask what causes inter-group aggression, how it is created, perpetuated and passed-on, but also how aggression can be avoided, diminished (Brewer & Gaertner, 2001, Gaertner et al., 1990) and turned into more productive effort to support human development. The outcome, ideally, is not only reflected in rational public discourse but moreover the institutionalization of rational behaviour and social norms.

Instead of pretending that there are ‘neutral’ or ‘impartial’ men representing the courts and independent agencies, it would be advisable to play with open cards and seek for a balanced and direct representation by political parties. Simple majority vote leads to ‘majority dictatorship’, so a 2/3 or 3/4 majority rule would force the majority to negotiate with the minority. Referendums of the people can compliment elections (Streckfuss D., 26th March, Post Publishing PLC, ‘ Risky road ahead in avoiding civil war’) while revitalizing the more democratic “People’s Constitution” of 1997 would be advisable to minimize the role of ‘power-brokers’, the powerful men behind the scenes that invite corruption and minimize transparency.

The act of responsibility is realized in fair intergroup negotiation and dialogue.



Adorno, T. W., Frenkel-Brunswik, E., Levinson, D. J., & Sanford, R. N. (1950). The authoritarian personality. New York: Harper and Row

Bronfenbrenner, U. (1979). The ecology of human development: Experiments by nature and design. Cambridge, MA: Harvard University Press.

Brewer, M. B.; Gaertner, S. L. (2001). “Toward reduction of prejudice: intergroup contact and social categorization”. In Brown, S. L.; Gaertner. Blackwell Handbook of Social Psychology: Intergroup processes 3 (1): 451–472.

Brewer, M. (1999). The Psychology of Prejudice: Ingroup Love or Outgroup Hate? Journal of Social issues, Vol. 55, No. 3, 1999, pp. 429-444 Retrieved from:

Dovido, J. F., Gaertner S.L., Saguy T., (2009) Commonality and the Complexity of “We”: Social Attitudes and Social Change. Personality and Social Psychology Review. Yale Univerity. Retrieved from:

Gaertner, S. L., Mann, J. A., Dovidio, J. F., Murrell, A. J., & Pomare, M. (1990). How does cooperation reduce intergroup bias? Journal of Personality and Social Psychology, 59, 692-704

Haslam, S. A.; Ellemers, N.; Reicher, S. D.; Reynolds, K. J.; Schmitt, M. T. (2010). “The social identity perspective today: An overview of its defining ideas”. In Postmes, T.; Branscombe, N. R. Rediscovering social identity (Psychology Press): 341–356.

Haslam, Alex; Oakes, Penny; Turner, John; McGarty, Craig (1996). “Social identity, self-categorization, and the perceived homogeneity of ingroups and outgroups: The interaction between social motivation and cognition”. In Sorrentino, Richard; Higgins, Edward. Handbook of motivation and cognition: the interpersonal context, Handbook of motivation and cognition (New York: Guilford Press) 3: 182–222.

Tajfel, H. (1974). “Social identity and intergroup behavior”. Social Science Information 13 (2): 65–93. doi:10.1177/053901847401300204.

Tajfel, H., & Turner, J. C. (1986). The social identity theory of intergroup behaviour. In S. Worchel & W. G. Austin (Eds.), Psychology of Intergroup Relations (pp. 7–24). Chicago, IL: Nelson-Hall.