In Memoriam: Adriaan Dingeman de Groot (1914 – 2006)

On August 14th, 2006, Adriaan de Groot passed away peacefully at the age of 91. De Groot changed Dutch empirical psychology significantly and also had a major impact on cognitive psychology in general.

Just before the start of the new millennium, de Groot was proclaimed the most influential Dutch psychologist ever by an international panel of renowned psychologists writing in the popular Psychologie Magazine, which was at that time the Dutch equivalent of Psychology Today (Busato, 1999). One panel member, Jan Elshout, emeritus professor of psychonomics, University of Amsterdam, said: “The most influential Dutch psychologist of this century, without any doubt, is Adriaan de Groot. He has done pioneering research in the areas of industrial psychology, educational psychology, and cognitive psychology, which is still being cited today.” Another panelist, K. Anders Ericsson, Conradi Eminent Scholar and professor of psychology at Florida State University, explained: “De Groot is the founding father of the empirical research on beginners and experts. His dissertation on the thinking patterns of chess players is a classical one in psychology.”  These sentiments are repeated in a variety of scientific publications. (Crombag 1984; van Strien & Hofstee 1995).

Mathematics
De Groot was born on the 26th of October, 1914, in Santpoort, a little village not far from Amsterdam. He grew up in an intellectually stimulating family together with two older brothers and sisters. At the age of five, just before entering primary school, he was already able to read and write. At the age of 17, he passed his high school exams with outstanding grades.

In 1932 he started studying mathematics and physics at the University of Amsterdam. After obtaining his bachelor’s degree, he switched to philosophy, with psychology as his main subject. His choice was influenced by personal contacts with psychoanalysts like Carl Jung and Alfred Adler at the International School of Philosophy in Amersfoort. In 1941, he obtained his doctorate in psychology, cum laude.

During World War II, it was not easy to get a job as a psychologist in the Netherlands, but de Groot had to earn a living for his young family. He was just married, with an infant daughter and a second child on the way. He taught mathematics for a few years at two secondary schools, one in Arnhem and one in Scheveningen. However, as he admitted, he had difficulty keeping order and teaching mathematics was clearly not his passion. At about the same time, de Groot also started working as an occupational psychologist for the Dutch Railways and Philips, doing recruitments and personality tests for management jobs. However, he didn’t like the commercial aspects of this work, however.

Chess
His ambitions were more scientific and, in fact, he already was working on a dissertation in his spare time (de Groot, 1946). In this study, which was awarded a cum laude laureate, de Groot compared the thinking and perceiving patterns of chess masters with those of amateurs. Chess masters, according to his conclusions, do not necessarily think more “deeply,” but rather they analyze the essence of a problem much faster — an observation that characterizes most areas of expertise. Also, chess masters perceive larger and more meaningful units of information at the same time. It was, in a sense, an “autobiographical” dissertation; de Groot himself was a master-level chess player and member of the Dutch national team in the 1930s.

Herbert Simon, the famous economist and psychologist at Carnegie-Mellon University, is generally seen as one of the founders of cognitive psychology due to his research on problem solving, thinking and decision processes. By coincidence, he heard about de Groot’s dissertation, sought it out, and with his knowledge of the German language, made his own translation. From then on, the two men were friends. Simon, a Nobel Prize laureate in 1978, explicitly acknowledged de Groot, with his dissertation, as the pioneer of cognitive psychology.

The English translation, Thought and Choice in Chess, published some 20 years later, is still often cited (de Groot, 1965) and is de Groot’s most influential work internationally. As Allen Newell observes, “It remains a goldmine for anyone working on human thinking and for anyone fascinated by chess” (1967).

And, indeed, this book still inspires psychologists worldwide. For example, Han van der Maas, professor of the analysis and modeling of non-linear psychological processes (especially in developmental psychology) at the University of Amsterdam, is co-author of two recent publications strongly based on de Groot’s dissertation (Maas & Wagemakers, 2005; van Harreveld, Wagemakers & van der Maas in press). “I was a student of de Groot’s students, and now I will be his successor,” van der Maas explains. “Soon I will be appointed the Chair in methodology that used to be his. Although, honestly, I wasn’t that conscious of the fact for some time, but my research agenda resembles very much that of de Groot: methodology, cognitive psychology, and educational psychology. De Groot has played a major part in the development of psychology in the Netherlands. Moreover, his dissertation is still very readable today. In my opinion, it is one of the most unique contributions ever made to cognitive psychology.”

K. Anders Ericsson (eg. 1980, 2006) also regularly references de Groot’s dissertation. When he was a graduate student at the University of Stockholm, Sweden, most of the cognitive psychologists he admired were American, such as Herbert Simon, Allen Newell, George Miller, and Gordon Bower. “However,” Ericsson says, “one of the few Europeans I also very much admired was Adriaan de Groot. I still recall reading his book on the analysis of ‘think-aloud’ protocols from chess masters.”

In the late 1970s Ericsson worked as a post-doc with Simon. “I was curious to learn how much Simon respected de Groot and how much effort he had invested in getting an English translation of de Groot’s dissertation. At the time of my post-doc de Groot’s research on chess experts’ memory and especially Bill Chase and Herb Simon’s (1973) famous continuation of that line of research defined the central issue of the information-processing theories of human cognition — namely the limited capacity of short-term memory. In fact, my work with Chase on the acquisition of exceptional digit spans collected protocols and designed experiments that allowed us to develop an alternative theoretical framework to account for de Groot’s and other researchers’ findings about experts’ superior memory. During the last three decades, de Groot’s pioneering work on reproducing the experts’ thought processes by presenting them with challenging representative tasks from their domain of expertise has led me and many of my colleagues to adopt an expert-performance approach to the study of expertise.”

Perpetuum Mobile
From 1949 till 1979, de Groot was a professor at the University of Amsterdam. First, his chair was in applied psychology. From 1960 till 1972, his chair switched to methodology and foundations of psychology. Besides his research on chess, de Groot has done some remarkable research in methodology, applied psychology, and educational psychology.

One of his most important contributions was his emphasis on empirical research, as expressed in his 1961 work on methodology, instead of trusting on speculation — which was relatively common in Dutch psychology until 1950 (de Groot, 1961; 1969). Several generations of Dutch students in the social sciences have been educated with his empirical cycle, which can be considered as a kind of perpetuum mobile. The cycle starts with observation: the systematic collecting of empirical facts and the formulating of hypotheses. The second phase is called induction: the hypotheses are formulated more accurately. Next is the phase of deduction: on the basis of those hypotheses, some specific predictions are formed. Subsequently, these predictions are empirically tested by collecting new data. In the fifth phase, the results are evaluated on their theoretical validity — then, the cycle starts again from the beginning. In Holland, this book became the “Bible” for empirical researchers in the social sciences in general, and in psychology in particular.).

Another contribution was de Groot’s work on selection and judgments in education. he felt that teachers shouldn’t have too much influence on that process; objective, multiple choice tests are better suited for judgments. De Groot elaborated on his ideas on this subject in another scientific bestseller(1966). In this book, which has not been translated, he pleads for a national institute for educational measurement. This institute — CITO — was actually founded by the Dutch Government in 1968. Today, CITO is one of the leading testing and assessment companies in the world.

Truth
From the 1970s up to his retirement, de Groot’s pace slowed somewhat, although he was often consulted by the government on educational matters. Moreover, he moved from Amsterdam to Schiermonnikoog, a small and beautiful island off the north coast of the Netherlands. In 1979, he accepted a Chair as professor at the University of Groningen, where his publications dealt more with the philosophy of science (1984; 1986a;1986b).

After his “definitive” retirement de Groot was not, as a Dutch expression says, “sitting behind his window, watching his geraniums grow.” Together with philosopher Henk Visser he published his last book (2003), which explained his ideas on the notion of scientific truth. To avoid false claims in the social sciences, according to de Groot, claims about the truth should be exposed to a forum of experts and they should agree unanimously on the truth of a claim. De Groot argued that, in the social sciences, this is the highest form of truth within human reach. Deteriorating heath threatened his ability to finish the book, but de Groot persevered on what he told Psychologie Magazine was his best idea ever (Bergsma, 2000).

Last, but definitely not least: at the age of 88, on the initiative of his five children, he recorded a CD of piano improvisations, expressing his lifelong love of classical music. De Groot explicitly considered this CD to be part of his impressive oeuvre.

References
Bergsma, Ad. (2000). De waarheid van Adriaan de Groot. Psychologie Magazine, June.
Busato, Vittorio. (1999). De psycholoog van de eeuw. Psychologie Magazine, December.
Chase, W. G., and Simon, H. A. (1973a). The mind’s eye in chess. In W. G. Chase, ed., Visual information processing, pp. 215–281. New York: Academic Press.
Chase, W.G. and Simon, H. A. (1973b).  Perception in chess. Cognitive Psychology, 4, 55-81.
Crombag, H.F.M. (1984). The conscience of Dutch psychology. Methodology and Science, 17(4), 218-229.
de Groot, A.D. (1946). Het denken van den schaker. Een experimenteel-psychologische studie. Amsterdam: Noord-Hollandsche Uitgeversmaatschappij.
de Groot, A.D. (1965). Thought and choice in chess. Amsterdam: Noord-Hollandsche Uitgeversmaatschappij.
de Groot, A.D. (1961). Methodologie. Grondslagen van onderzoek en denken in de gedragswetenschappen. Den Haag: Mouton & Co.
de Groot, A.D. (1969). Methodology. Foundations of inference and research in the behavioral sciences. The Hague-Paris: Mouton & Co.
de Groot, A.D. (1966). Vijven en zessen. Cijfers en beslissingen: het selectieproces in ons onderwijs. Groningen: Wolters-Noordhoff.
de Groot, A.D. (1984). The theory of the science forum: subject and purport. Methodology & Science, 17(4), 230-259.
de Groot, A.D. (1986). Begrip van evalueren. Den Haag: Vuga Uitg.
de Groot, A.D. & Medendorp, F.L. (1986). Term, Begrip, Theorie. Inleiding tot signifische begripsanalyse. Amsterdam-Meppel: Boom.
de Groot, A.D. & Visser, H. (2003). Het forumwaarmerk van wetenschap: argumenten voor een nieuwe traditie. Amsterdam: Koninklijke Nederlandse Akademie voor Wetenschapppen.
Ericsson, K. A., Charness, N., Feltovich, P., & Hoffman, R. R. (2006). Cambridge handbook of expertise and expert performance. Cambridge, UK: Cambridge University Press.
Ericsson, K. A., & Simon, H. A. (1980). Verbal reports as data. Psychological Review, 87, 215-251.
Newell, A. (1967). Without benefit of the computer. Science, 156(3776), 803-804. Quote p. 804.
van der Maas, H.L.J. der & Wagenmakers, E.-J. (2005). The Amsterdam Chess Test: A psychometric analysis of chess expertise. American Journal of Psychology, 118, 29-60.
van Harreveld, F., Wagenmakers, E.-J., & Maas, H. L. J. van der (in press). The effects of time pressure on chess skill: An investigation into fast and slow processes underlying expert performance. Psychological Research.
Simon, H. A., and W. G. Chase, W.G. (1973).  Skill in chess.  American Scientist, 61, 394-403.
van Strien, P.J. & Hofstee, W.K.B. (1995). An interview with Adriaan D. de Groot. New Ideas in Psychology, 15(3), 341-356.