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.