Heider, Fritz

From New World Encyclopedia
Line 2: Line 2:
 
{{epname|Heider, Fritz}}
 
{{epname|Heider, Fritz}}
  
'''Fritz Heider''' (1896-1988) was an Austrian American [[psychology|psychologist]] whose work was related to the [[gestalt psychology|Gestalt]] school. Heider's 1958 book ''The Psychology of Interpersonal Relations'' is a theoretical masterpiece that laid the foundations for much of contemporary [[social psychology]], in particular, the large bodies of work on '''attribution''', '''balance''', and '''cognitive consistency'''. Heider is considered to be one of [psychology]]'s pre-eminent theorists.
+
'''Fritz Heider''' (1896-1988) was an Austrian American [[psychology|psychologist]] whose work was related to the [[gestalt psychology|Gestalt]] school. Heider's 1958 book ''The Psychology of Interpersonal Relations'' is a theoretical masterpiece that laid the foundations for much of contemporary [[social psychology]], in particular, the large bodies of work on [[attribution (psychology)|attribution]], '''balance''', and '''cognitive consistency'''. Heider is considered to be one of psychology's pre-eminent theorists.
  
= Life =
+
== Life ==
  
Fritz Heider was born in [[Vienna]], [[Austria]] on 19 February, 1896. He grew up in ''Graz'' as the second son of ''Moriz Heider'', a prosperous archtect, and his wife Eugenie. Around the age of 10, he suffered damage to the retina of his left eye while playing with a cap pistol. This had the effect of making him more introverted as well as more interested in the processes affecting visual perception. His interest in perception was further developed in the painting and sketching he did throughout his adolescent and young adult years.
+
Fritz Heider was born in [[Vienna]], [[Austria]] on 19 February, 1896. He grew up in [[Graz]] as the second son of Moriz Heider, a prosperous [[architecture|architect]], and his wife Eugenie. Around the age of ten, he suffered damage to the [[retina]] of his left eye while playing with a cap pistol. This had the effect of making him more introverted as well as more interested in the processes affecting visual perception. His interest in perception was further developed in the painting and sketching he did throughout his adolescent and young adult years.
 +
 
 +
His approach to [[higher education]] was rather casual, and he wandered freely throughout Europe studying and traveling as he pleased for many years. On his father's encouragement, Fritz Heider studied first [[architecture]], and then [[law]] in Graz, but soon became bored with both subjects. He persuaded his father to let him simply audit university courses for four years, promising that afterward he would raise pigs for a living. Gradually, as his interests began to focus, his studies became more concentrated in the areas of [[philosophy]] and [[psychology]]. After seeing other students begin work on their doctoral dissertation, Heider asked his adviser, [[Alexius Meinong]], if he could attempt to write one as well. This request was granted, and Heider eventually submitted his thesis in March 1920. At the age of 24 he received a Ph.D. from the University of Graz, and traveled to [[Berlin]], where he lived with his uncle Karl and his cousin Doris, while attending lectures at the Psychological Institute.
  
His approach to higher education was rather casual, and he wandered freely throughout Europe studying and traveling as he pleased for many years. On his father's encouragement, Fritz Heider studied first [[architecture]], and then [[law]] in ''Graz'', but soon became bored with both subjects. He persuaded his father to let him simply audit university courses for 4 years, promising that afterward he would raise pigs for a living. Gradually, as his interests began to focus, his studies became more concentrated in the areas of [[philosophy]] and [[psychology]]. After seeing other students begin work on their doctoral dissertation, Heider asked his asviser, ''Alexius Meinong'', if he could attempt to write one as well. This request was granted, and Heider eventually submitted his thesis in March 1920. At the age of 24 he received a Ph.D. from the ''University of Graz'', and traveled to Berlin, where he lived with his uncle Karl and his cousin Doris, while attending lectures at the ''Psychological Institute''.
 
 
His studies there focused on the [[Gestalt psychology]] of [[Max Wertheimer]] and [[Wolfgang Köhler]]. Fritz Heider was also strongly influenced by his association with [[Kurt Lewin]] continued after both men had emigrated to America in the early 1930s, up to the the time of Lewin's death in 1947.
 
His studies there focused on the [[Gestalt psychology]] of [[Max Wertheimer]] and [[Wolfgang Köhler]]. Fritz Heider was also strongly influenced by his association with [[Kurt Lewin]] continued after both men had emigrated to America in the early 1930s, up to the the time of Lewin's death in 1947.
  
In 1930, Heider was offered an opportunity to conduct research at the ''Clarke School for the Deaf'' in ''Northampton'', [[Massachusetts]], which was associated with ''Smith College'', also in ''Northampton''. This prospect was particularly attractive to him because [[Kurt Koffka]], one of the founders of the ''Gestalt school of psychology'', held a position at ''Smith College'' (Heider, 1983).  
+
In 1930, Heider was offered an opportunity to conduct research at the [[Clarke School for the Deaf]] in Northampton, [[Massachusetts]], which was associated with [[Smith College]], also in Northampton. This prospect was particularly attractive to him because Kurt Koffka held a position at Smith (Heider 1983).  
  
It was in Northampton that he met his wife Grace (neé Moore). Grace was one of the first people Heider met in the United States. As an assistant to Koffka, she helped Heider find an apartment in Northampton and introduced him to the environs (Heider, 1983). They were married in 1930, and the marriage lasted for more than 50 years, producing three sons: Karl, John, and Stephan (in birth order). ''Karl Heider'' went on to become an important contributor to visual anthropology and ethnographic film. ''John Heider'' wrote the popular ''The Tao of Leadership''.
+
It was in Northampton that he met his wife Grace (neé Moore). Grace was one of the first people Heider met in the United States. As an assistant to Koffka, she helped Heider find an apartment in Northampton and introduced him to the environs (Heider 1983). They were married in 1930, and the marriage lasted for more than 50 years, producing three sons: Karl, John, and Stephan (in birth order). [[Karl Heider]] went on to become an important contributor to visual [[anthropology]] and [[ethnography|ethnographic]] film. [[John Heider]] wrote the popular ''The Tao of Leadership''.
  
 
Fritz Heider died on 2 January 1988, at the age of 91.
 
Fritz Heider died on 2 January 1988, at the age of 91.
  
= Work =
+
== Work ==
 +
 
 +
Heider published two important articles in 1944 that pioneered the concepts of social perception and causal attribution (Heider 1944; Heider & Simmel 1944). After this point, however, Heider published little for the next 14 years.
  
Heider published two important articles in 1944 that pioneered the concepts of social perception and causal attribution (Heider, 1944; Heider & Simmel, 1944). After this point, however, Heider published little for the next 14 years.
+
Having been fascinated with the cognitive dynamics of interpersonal relations since his young adult years in Graz during [[World War I]], Heider subsequently spent more of his time attempting to analyze them. Using [[concept]]s drawn from [[folk psychology|commonsense psychology]], he analyzed the plots of [[Aesop]]'s [[fable]]s, [[play]]s by [[Henrik Ibsen]], [[Jean Racine]], and other playwrights, and dozens of short stories and jokes. His goal was to reduce them to a set of fundamental concepts that could be linked by a set of equally fundamental relations.
  
Having been fascinated with the ''cognitive dynamics of interpersonal relations'' since his young adult years in ''Graz'' during [[World War I]], Fritz Heider subsequently spent more of his time attempting to analyze them. Using [[concept]]s drawn from '''commonsense psychology''', he analyzed the plots of [[Aesop]]'s fables, plays by [[Henrik Ibsen]], [[Jean Racine]], and other playwrights, and dozens of short stories and jokes. His goal was to reduce them to a set of fundamental ''concept''s that could be linked by a set of equally fundamental relations.
+
In 1957, Heider was hired by the [[University of Kansas]], after being recruited by social psychologist [[Roger Barker]] (Heider 1983). Shortly thereafter, Heider published his most famous work, which remains his most significant contribution to the field of [[social psychology]].
  
In 1957, Heider was hired by the ''University of Kansas'', after being recruited by social psychologist ''Roger Barker'' (Heider, 1983). Shortly thereafter, Heider published his most famous work, which remains his most significant contribution to the field of social psychology.
+
=== ''The Psychology of Interpersonal Relations'' ===
  
== The Psychology of Interpersonal Relations ==
+
Heider's ''The Psychology of Interpersonal Relations'' (1958) was written in collaboration with the uncredited [[Beatrice Wright]], a founder of [[rehabilitiation psychology]]. Beatrice Wright was available to collaborate because the University of Kansas' [[nepotism]] rules prohibited her from a position at the University (her husband, [[Erik Wright]], was a professor there), and the [[Ford Foundation]] gave Heider funds and assistance to complete the project. (Wright is credited only in the Foreword; she later went on to become an endowed professor of psychology at the University of Kansas).
  
Heider's ''The Psychology of Interpersonal Relations'' (1958) was written in collaboration with the uncredited ''Beatrice Wright'', a founder of '''rehabilitiation psychology''. ''Beatrice Wright'' was available to collaborate because the University of Kansas's nepotism rules prohibited her from a position at the University (her husband, ''Erik Wright'', was a professor there), and the [[Ford Foundation]] gave Heider funds and assistance to complete the project. (Wright is credited only in the Foreword; she later went on to become an endowed professor of psychology at the ''University of Kansas'').
+
''The Psychology of Interpersonal Relations'' contains several ideas that influenced the further development of [[social psychology]]. Heider argued that [[social perception]] follows many of the same rules of physical object [[perception]], and that the organization found in object perception is also found is social perception. Because biases in object perception sometimes lead to errors (for example in [[optical illusion]]s), one might expect to find that biases in social perception likewise can lead to errors (such as underestimating the role social factors and overestimating the effect of [[personality]] and [[attitude]]s on [[human behavior]]). Fritz Heider also argued that the order people put on their perceptions followed the rule of "psychological balance." His basic idea is that positive and negative sentiments need to be represented in ways that minimize ambivalence and maximize a simple, straightforward affective representation of the person:
 +
<blockquote>To conceive of a person as having positive and negative traits requires a more sophisticated view; it requires a differentiation of the representation of the person into subparts that are of unlike value (Heider 1958, 182).</blockquote>
  
''The Psychology of Interpersonal Relations'' contains several ideas that has influenced the further development of [[social psychology]]. Heider argued that '''social perception''' follows many of the same rules of physical object perception, and that the organization found in object [[perception]] is also found is social perception. Because biases in object perception sometimes lead to errors (e.g., ''optical illusions''), one might expect to find that biases in social perception likewise can lead to errors (e.g., underestimating the role social factors and overestimating the effect of [[personality]] and [[attitude]]s on '''behavior'''). Fritz Heider also argued that the order people put on their perceptions followed the rule of '''psychological balance'''. Although tedious to spell out in completeness, the idea is that positive and negative sentiments need to be represented in ways that minimize ambivalence and maximize a simple, straightforward affective representation of the ''person''. He writes "To conceive of a person as having positive and negative traits requires a more sophisticated view; it requires a differentiation of the representation of the person into subparts that are of unlike value (1958, p. 182)."
+
But the most important idea in ''The Psychology of Interpersonal Relations'' is the notion of how people see the causes of behavior, and the explanations they make for it—what Heider called "[[attribution (psychology|attributions]]." [[Attribution theory]] (as one part of the larger and more complex Heiderian account of social perception) describes how people come to explain (make attributions about) the behavior of others and themselves. Behavior is attributed to a disposition (such as [[personality]] traits, [[motivation|motives]], [[attitude]]s), or behavior can be attributed to situations (for example, external pressures, [[social norm]]s, peer pressure, accidents of the environment, "acts of God," [[randomness|random]] chance, and so forth). Heider first made the argument that people tend to overweight internal, dispositional causes over external causes—this later became known as the "fundamental attribution error" (Ross 1977) or "correspondence bias" (Fiske & Taylor 1991; Jones 1979, 1990).
  
But the most important idea in ''The Psychology of Interpersonal Relations'' is the notion of how people see the ''causes of behavior'', and the explanations they make for it — what Heider called ''attributions''. [[Attribution theory]] (as one part of the larger and more complex Heiderian account of ''social perception'') describes how people come to explain (make attirbutions about) the behavior of others and themselves. Behavior is attributed to a disposition (e.g., ''personality traits'', ''motives, [[attitude]]s), or behavior can be attributed to ''situations'' (e.g., ''external pressures'', ''social norms'', ''peer pressure'', ''accidents of the environment'', ''acts of God'', ''random chance'', etc.) Heider first made the argument that people tend to overweight internal, dispositional causes over external causes — this later became known as the ''fundamental attribution error'' (Ross, 1977) or ''correspondence bias'' (Fiske & Taylor, 1991; Jones, 1979, 1990).
+
== Legacy ==
  
= Legacy =
+
''The Psychology of Interpersonal Relations'' essentially founded the modern field of [[social cognition]]. A giant of [[social psychology]], Fritz Heider had few students, but his book on social perception had many readers, and its impact has continued into the twenty-first century.
  
''The Psychology of Interpersonal Relations'' essentially founded the modern field of social cognition. A giant of social psychology, Fritz Heider had few students, but his book on social perception had many readers, and its impact continues into the 21st century, having been cited nearly 4,000 times.
+
Heider credited his intense study of [[proposition]]s set forth in [[Spinoza]]'s ''Ethics'' as a major source of his insights regarding ''balanced versus imbalanced cognitive structure'' (Heider 1983).
  
Heider credited his intense study of propositions set forth in [[Spinoza]]'s ''Ethics'' as a major source of his insights regarding ''balanced versus imbalanced cognitive structure'' (Heider, 1983).
+
Heider systematized and expanded upon his creation of "balance theory" and [[attribution theory]]. He is also remembered for his early and important contributions to the study of [[perception]].  
Heider systematized and expanded upon his creation of '''balance theory''' and [[attribution theory]]. He is also remembered for his early and important contributions to the study of [[perception]].  
 
  
The [[American Psychological Association]] awarded Heider the ''Distinguished Scientific Contribution Award'' in 1965 and the ''Psychological Science Gold Medal Award'' in 1987. The contents of Heider's notebooks, which had accumulated over decades, were edited by Marijana Benesh-Weiner and published in six volumes, from 1987 to 1990.Unlike his friend [[Kurt Lewin]], who was assertive, energetic, and charismatic, Fritz Heider was gentle, reflective, and unassuming. No less than [[Kurt Lewin]], ''Fritz Heider'' has had a theoretical influence on [[social psychology]] that is both pervasive and enduring.
+
The [[American Psychological Association]] awarded Heider the Distinguished Scientific Contribution Award in 1965 and the Psychological Science Gold Medal Award in 1987. The contents of Heider's notebooks, which had accumulated over decades, were edited by Marijana Benesh-Weiner and published in six volumes, from 1987 to 1990. Unlike his friend [[Kurt Lewin]], who was assertive, energetic, and [[charisma]]tic, Fritz Heider was gentle, reflective, and unassuming. No less than Kurt Lewin, however, Fritz Heider has had a theoretical influence on social psychology that is both pervasive and enduring.
  
== Fritz Heider's Works ==
+
== Major works ==
  
 
* Heider, F. 1926. Ding und Medium.. ''Symposium, 1'', 109-157.
 
* Heider, F. 1926. Ding und Medium.. ''Symposium, 1'', 109-157.

Revision as of 18:46, 27 June 2008

Fritz Heider (1896-1988) was an Austrian American psychologist whose work was related to the Gestalt school. Heider's 1958 book The Psychology of Interpersonal Relations is a theoretical masterpiece that laid the foundations for much of contemporary social psychology, in particular, the large bodies of work on attribution, balance, and cognitive consistency. Heider is considered to be one of psychology's pre-eminent theorists.

Life

Fritz Heider was born in Vienna, Austria on 19 February, 1896. He grew up in Graz as the second son of Moriz Heider, a prosperous architect, and his wife Eugenie. Around the age of ten, he suffered damage to the retina of his left eye while playing with a cap pistol. This had the effect of making him more introverted as well as more interested in the processes affecting visual perception. His interest in perception was further developed in the painting and sketching he did throughout his adolescent and young adult years.

His approach to higher education was rather casual, and he wandered freely throughout Europe studying and traveling as he pleased for many years. On his father's encouragement, Fritz Heider studied first architecture, and then law in Graz, but soon became bored with both subjects. He persuaded his father to let him simply audit university courses for four years, promising that afterward he would raise pigs for a living. Gradually, as his interests began to focus, his studies became more concentrated in the areas of philosophy and psychology. After seeing other students begin work on their doctoral dissertation, Heider asked his adviser, Alexius Meinong, if he could attempt to write one as well. This request was granted, and Heider eventually submitted his thesis in March 1920. At the age of 24 he received a Ph.D. from the University of Graz, and traveled to Berlin, where he lived with his uncle Karl and his cousin Doris, while attending lectures at the Psychological Institute.

His studies there focused on the Gestalt psychology of Max Wertheimer and Wolfgang Köhler. Fritz Heider was also strongly influenced by his association with Kurt Lewin continued after both men had emigrated to America in the early 1930s, up to the the time of Lewin's death in 1947.

In 1930, Heider was offered an opportunity to conduct research at the Clarke School for the Deaf in Northampton, Massachusetts, which was associated with Smith College, also in Northampton. This prospect was particularly attractive to him because Kurt Koffka held a position at Smith (Heider 1983).

It was in Northampton that he met his wife Grace (neé Moore). Grace was one of the first people Heider met in the United States. As an assistant to Koffka, she helped Heider find an apartment in Northampton and introduced him to the environs (Heider 1983). They were married in 1930, and the marriage lasted for more than 50 years, producing three sons: Karl, John, and Stephan (in birth order). Karl Heider went on to become an important contributor to visual anthropology and ethnographic film. John Heider wrote the popular The Tao of Leadership.

Fritz Heider died on 2 January 1988, at the age of 91.

Work

Heider published two important articles in 1944 that pioneered the concepts of social perception and causal attribution (Heider 1944; Heider & Simmel 1944). After this point, however, Heider published little for the next 14 years.

Having been fascinated with the cognitive dynamics of interpersonal relations since his young adult years in Graz during World War I, Heider subsequently spent more of his time attempting to analyze them. Using concepts drawn from commonsense psychology, he analyzed the plots of Aesop's fables, plays by Henrik Ibsen, Jean Racine, and other playwrights, and dozens of short stories and jokes. His goal was to reduce them to a set of fundamental concepts that could be linked by a set of equally fundamental relations.

In 1957, Heider was hired by the University of Kansas, after being recruited by social psychologist Roger Barker (Heider 1983). Shortly thereafter, Heider published his most famous work, which remains his most significant contribution to the field of social psychology.

The Psychology of Interpersonal Relations

Heider's The Psychology of Interpersonal Relations (1958) was written in collaboration with the uncredited Beatrice Wright, a founder of rehabilitiation psychology. Beatrice Wright was available to collaborate because the University of Kansas' nepotism rules prohibited her from a position at the University (her husband, Erik Wright, was a professor there), and the Ford Foundation gave Heider funds and assistance to complete the project. (Wright is credited only in the Foreword; she later went on to become an endowed professor of psychology at the University of Kansas).

The Psychology of Interpersonal Relations contains several ideas that influenced the further development of social psychology. Heider argued that social perception follows many of the same rules of physical object perception, and that the organization found in object perception is also found is social perception. Because biases in object perception sometimes lead to errors (for example in optical illusions), one might expect to find that biases in social perception likewise can lead to errors (such as underestimating the role social factors and overestimating the effect of personality and attitudes on human behavior). Fritz Heider also argued that the order people put on their perceptions followed the rule of "psychological balance." His basic idea is that positive and negative sentiments need to be represented in ways that minimize ambivalence and maximize a simple, straightforward affective representation of the person:

To conceive of a person as having positive and negative traits requires a more sophisticated view; it requires a differentiation of the representation of the person into subparts that are of unlike value (Heider 1958, 182).

But the most important idea in The Psychology of Interpersonal Relations is the notion of how people see the causes of behavior, and the explanations they make for it—what Heider called "attributions." Attribution theory (as one part of the larger and more complex Heiderian account of social perception) describes how people come to explain (make attributions about) the behavior of others and themselves. Behavior is attributed to a disposition (such as personality traits, motives, attitudes), or behavior can be attributed to situations (for example, external pressures, social norms, peer pressure, accidents of the environment, "acts of God," random chance, and so forth). Heider first made the argument that people tend to overweight internal, dispositional causes over external causes—this later became known as the "fundamental attribution error" (Ross 1977) or "correspondence bias" (Fiske & Taylor 1991; Jones 1979, 1990).

Legacy

The Psychology of Interpersonal Relations essentially founded the modern field of social cognition. A giant of social psychology, Fritz Heider had few students, but his book on social perception had many readers, and its impact has continued into the twenty-first century.

Heider credited his intense study of propositions set forth in Spinoza's Ethics as a major source of his insights regarding balanced versus imbalanced cognitive structure (Heider 1983).

Heider systematized and expanded upon his creation of "balance theory" and attribution theory. He is also remembered for his early and important contributions to the study of perception.

The American Psychological Association awarded Heider the Distinguished Scientific Contribution Award in 1965 and the Psychological Science Gold Medal Award in 1987. The contents of Heider's notebooks, which had accumulated over decades, were edited by Marijana Benesh-Weiner and published in six volumes, from 1987 to 1990. Unlike his friend Kurt Lewin, who was assertive, energetic, and charismatic, Fritz Heider was gentle, reflective, and unassuming. No less than Kurt Lewin, however, Fritz Heider has had a theoretical influence on social psychology that is both pervasive and enduring.

Major works

  • Heider, F. 1926. Ding und Medium.. Symposium, 1, 109-157.
  • Heider, F. (1944). Social perception and phenomenal causality. Psychological Review, 51, 358-374.
  • Heider, F. 1946. Attitudes and cognitive organization. Journal of Psychology, 21, 107112.
  • Heider, F, & Simmel, M. (1944). An experimental study of apparent behavior. American Journal of Psychology, 57, 243-259.
  • Heider, F. (1958). The psychology of interpersonal relations. New York: John Wiley & Sons.
  • Heider, F. 1959. On perception, event stucture, and psychological environment. Psychological Issues, 1, 1-123.
  • Heider, F. (1983). The life of a psychologist: An autobiography. Lawrence, KS: University of Kansas Press.
  • Heider, F. & Simmel, M. 1944. An experimental study of apparent behavior. American Journal of Psychology, 57, 243-259.
  • Heider, F. & Benesh-Weiner, M. 1987/1990. The notebooks: Volumes 1-6. Munich: Psychologie Verlags Union.

References
ISBN links support NWE through referral fees

  • Argyris, C. 1970. Intervention Theory and Method. Reading, MA: Addison-Wesley.
  • Argyris, C. 1980. Inner Contradictions of Rigorous Research. San Diego CA: Academic Press.
  • Ben-David, J. and R. Collins. 1966. Social factors in the origin of a new science: The case of psychology. American Psychological Review, 31, pp. 451-465.
  • Brennan, J.F. 1982. History and Systems of Psychology. Englewood Cliffs, New Jersey: Prentice-Hall, Inc.
  • Brunswik, E. 1956. Perception and representative design of psychological experiments. Berkeley, CA: University of California Press.
  • Fiske, S.T., & Taylor, S.E. (1991). Social cognition (2nd ed.). New York: McGraw-Hill.
  • Cartwright, D. [1951] 1997. Field Theory in Social Science and Selected Theoretical Papers-Kurt Lewin. Washington, D.C.: American Psychological Association.
  • Gibson, J. J. 1950. The perception of visual world. New York: Houghton-Mifflin.
  • Jones, E.E. 1979. The rocky road from acts to dispositions. American Psychologist, 34, 107-117.
  • Jones, E.E. 1990. Interpersonal perception. New York: Freeman.
  • Leahey, Th. H. 1991. A History of Modern Psychology. Englewood Cliff, New Jersey: Prentice Hall.
  • Lewin, K. 1936. Principles of topological psychology. New York: McGraw Hill.
  • Lewin, K. 1959. A Dynamic Theory of Personality. McGraw-Hill.
  • Reason & Bradbury. 2001. Handbook of Action Research. London: Sage.
  • Ross, L. 1977. The intuitive psychologist and his shortcomings: Distortions in the attribution process. In L. Berkowitz (Ed.), Advances in experimental social psychology (Vol. 10, pp. 173-220). Orlando, FL: Academic Press.
  • Spinoza, B. 1936. Philosophy of B. de Spinoza (R. H. M. Elwes, Trans.), New York: Tudor. Original work published in 1677.

External links

Credits

New World Encyclopedia writers and editors rewrote and completed the Wikipedia article in accordance with New World Encyclopedia standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License (CC-by-sa), which may be used and disseminated with proper attribution. Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here:

The history of this article since it was imported to New World Encyclopedia:

Note: Some restrictions may apply to use of individual images which are separately licensed.