Hermann Ebbinghaus

Early life

Hermann Ebbinghaus was born on 24 January 1850 in Barmen, in the Rhine Province of the Kingdom of Prussia, near Bonn. He was the son of a wealthy merchant, Carl Ebbinghaus. Little is known about his childhood, except that he was raised in the Lutheran faith and attended the town gymnasium.

Education

At seventeen, in 1867, he entered the University of Bonn intending to study history and philology, but his interest gradually turned to philosophy. In 1870 his studies were interrupted when he served with the Prussian army in the Franco-Prussian War, a brief period of military service. After it, he completed a dissertation on Eduard von Hartmann's philosophy of the unconscious and received his doctorate on 16 August 1873, at the age of twenty-three. Over the next three years he spent time in Halle and Berlin.

Tutoring years and the discovery of Fechner

With his doctorate in hand, Ebbinghaus moved through England and France, tutoring students to earn a living. In England he may have taught at two small schools in the south of the country, though the details are uncertain. In a secondhand bookshop in London he came across Gustav Fechner's Elements of Psychophysics, which led him to begin experiments on memory. He took Fechner's approach as a starting point for measuring a mental process that had until then been discussed mainly in philosophical terms.

A method for measuring memory

In 1879, now in Berlin, Ebbinghaus began his research in the psychological laboratory he founded there, the third of its kind in Germany after those of Wilhelm Wundt and Georg Elias Müller. His aim was to show that higher mental processes could be studied experimentally, a view that was widely contested at the time. To separate memory from prior knowledge, he needed material with no existing meaning, so he used nonsense syllables of the consonant-vowel-consonant type, such as DAX or BOK, excluding any that suggested familiar words. He assembled around 2,300 of them. He drew random syllables from a box, read them aloud in time with a metronome and in the same tone, and then tried to recall them, treating the number of repetitions needed as a measure of memory. He was his own sole subject, and a single investigation required some 15,000 recitations. It was later found that people give even nonsense syllables some meaning, since they differ in their associative value.

Principal work and findings

In 1880 he was admitted as a lecturer at the University of Berlin, and in 1885 he published his foundational work, On Memory (Über das Gedächtnis), describing experiments he had carried out on himself to study learning and forgetting. Several of its findings remain well known. The forgetting curve describes the exponential loss of learned material: the decline is steepest in the first twenty minutes, remains significant through the first hour, and levels off after about a day. The learning curve shows that the greatest gain comes at the first attempt, with each later repetition adding less new information. He also described the serial position effect, in which items at the beginning and end of a list are better remembered than those in the middle, and the phenomenon of savings, whereby material that can no longer be consciously recalled leaves a trace that makes relearning faster. He further distinguished involuntary memory, which arises spontaneously, from voluntary memory, which is brought into consciousness through an effort of will. The book earned him the title of extraordinary professor at Berlin in 1886.

Later work

Although he did not continue his memory research, Ebbinghaus remained active. In 1890 he co-founded, with Arthur König, the journal Zeitschrift für Psychologie und Physiologie der Sinnesorgane. In 1893 he published a theory of colour vision, and in 1894 he took up the chair at Breslau after being passed over for promotion in Berlin. In Breslau he sat on a commission that studied how schoolchildren's mental ability declined over the course of the school day, and in 1897 he proposed a completion test for assessing children's mental capacity. In 1902 he published Fundamentals of Psychology (Grundzüge der Psychologie), which was an immediate success and remained widely read long after his death. In 1904 he moved to Halle, where he spent his final years, and in 1908 his last work, Outline of Psychology, appeared in eight editions.

Reception and legacy

Ebbinghaus died of pneumonia in Halle on 26 February 1909, at the age of fifty-nine. His greatest legacy is having shown that memory, a higher mental process, could be studied through experimental and quantitative methods, opening a path that cognitive psychology later followed. Concepts such as the forgetting curve and the spacing effect remain part of current research. His limitations are also well recognised: because he was the only subject of his study, his results have limited generalisability, and his approach left more complex aspects of memory, such as semantic and procedural memory, largely unexplored.