Historical Background

Just like Drosophila – the fruit fly – is a model organism in genetics, chess has long served as a model task environment (similar to how is a model in genetics Drosophila – fruit fly) for research into psychological processes (Charness, 1992). Some of the earliest systematic work on individual differences in imagery (Binet, 1893/1966; 1894), memory (Djakow, Petrowski, & Rudik, 1927), and problem solving (de Groot 1946/1965) took place in the domain of chess. Cleveland (1907) was one of the first to identify the importance of complex units, now called chunks, in skilled play and speculated that intellectual abilities might be poor predictors of chess skill, even providing the score of a game played with a “mentally feeble” individual.

De Groot (1946/1965) ushered in the modern era of investigation using small groups of expert and grandmaster-level players in experimental studies. Of de Groot's many findings, it was the dissociation between thinking skills and perceptual-memory skills that laid the groundwork for subsequent research. When asking players to think aloud while they attempted to choose the best move in an unfamiliar position, de Groot discovered that, contrary to popular lore, the most-proficient players did not think further ahead than less-skilled practitioners. It was a different experimental task – memory for briefly presented chess positions – that markedly differentiated skill levels. De Groot found that skilled players proved to have strikingly superior memory for chess positions after brief presentations (two to fifteen seconds), compared to their less-proficient counterparts.

Introduction

Outstanding accomplishments by older individuals, such as the wisdom of elderly statesmen, the virtuoso performances of older musicians, or the swan-song oeuvres of famous composers have been the subject of admiration throughout human history. Commonsense or folk psychology rarely considers such achievements as incompatible with older age. On the contrary, in the public's opinion advanced age has been identified with maturity or heightened levels of experience that complement the exceptional talents or gifts that had presumably enabled outstanding individuals to surpass ordinary people in the first place. Allegedly, these dispositions are the driving force leading to high achievements, and the presumed stability of related capacities is believed to guarantee that outstanding individuals' superior skills remain at their disposition throughout adulthood. In traditionalist cultures (as in Germany or Japan) such appreciations of early achievement and seniority overshadow actual accomplishments and remain an integral part of society and job promotion until this day.

The scientific study of interindividual differences and the experimental investigation of human performance in normal adults portray a less optimistic picture of adult development, at least in the normal population. Ubiquitous findings of negative age-graded changes in psychometric ability factors and reduced speed or accuracy in most cognitive-motor tasks have motivated theories of broad decline, like the notion of general, age-related slowing (Salthouse, 1985a). In the light of these findings, the accomplishments by older experts and the high performance levels in many older professionals present a puzzle.