Hermann Ebbinghaus

Hermann Ebbinghaus (1850 – 1909) was a German philosopher and psychologist who pioneered numerous experimental studies of memory. He is famous for his discovery of the "forgetting curve." Ebbinghaus also introduced fundamental scientific techniques to the field of psychology. Establishing multiple laboratories throughout Central Europe for purposes of psychological research and study, Ebbinghaus is often credited with the advancement and promotion of the psychological field in its earliest years. Thus, the legacy of Ebbinghaus continues to inform our understanding of human cognition, with implications for the betterment of education and many other areas of human society.



Hermann Ebbinghaus was born on January 24, 1850 to a family of Lutheran merchants in Barmen, Germany. At the age of 17, Ebbinghaus entered the University of Bonn where he studied aspects of philosophy, history, and psychology. In 1870 his studies were interrupted by the Franco-Prussian War in which he enlisted as a member of the Prussian army. Following the war Ebbinghaus continued his formal education at the universities of Halle and Berlin, eventually earning a Ph.D in philosophy from the University of Bonn in 1873. After receiving his degree, he studied independently throughout parts of Berlin, France, and England, conducting his first set of memory experiments in 1878.

Ebbinghaus returned to Germany to serve as a lecturer at the University of Berlin, conducting his second set of memory experiments in 1883. Known for his candid humor and personal charm, Ebbinghaus became a popular professor, highly regarded by university teachers, and dearly loved by students. In 1886, he established and opened an experimental psychology laboratory at the University of Berlin for purposes of psychological research and study. In the years following, Ebbinghaus co-founded the Zeitschrift fur Psychology und Physiologie der Sinnersorgane (Journal of Psychology and Physiology of the Sense Organs), a literary establishment often credited with the international advancement of psychological study. From 1894 to 1905 Ebbinghaus served as a professor at the University of Breslau, (now Wrocław, Poland) where he founded a second psychology laboratory in 1894. From 1905 until 1908 he served as a professor for the University of Halle. In 1909, Ebbinghaus succumbed to pneumonia, dying in Breslau at the age of 59.


In 1885 while at the University of Berlin, Ebbinghaus published his groundbreaking Über das Gedchtnis (On Memory), in which he described experiments he conducted on himself to describe the process of forgetting. This publication was later translated into the English language as Memory: A Contribution to Experimental Psychology and is regarded as one of the most influential psychology texts in print.

Within this work, Ebbinghaus set out to counter the assertion made by German physiologist Wilhelm Wundt who claimed human memory to be incapable of experimental study. Influenced by the work of German psychophysicist Gustav Fechner, Ebbinghaus incorporated mathematical analysis into studies of sensation and perception to identify the presence of a forgetting curve within the human memory. Working as both experimenter and subject, Ebbinghaus’ forgetting curve identified a distinct correlation between memory retention and time, illustrating a decline in the amount of information retained by the human memory over time.

Ebbinghaus’ On Memory also studied areas of immediate memory and analyzed comparative learning rates regarding significant and insignificant sets of information. Ebbinghaus found more significant material to be retained longer by the human memory and less insignificant data to be more easily disregarded. Coining the term "nonsense syllable," Ebbinghaus reinvented the psychological study of association and learning through his experimental techniques.

His experiments demonstrated empirically that meaningless stimuli are more difficult to memorize than meaningful information. His data also revealed that increasing the amount of material to be learned generally increased the amount of time it took to learn it. This is known as the "learning curve." He established that relearning is easier than initial learning, and that it takes longer to forget material after each subsequent re-learning.

In 1897, while at the University of Breslau, Ebbinghaus began studying the mental capabilities of children, eventually developing a sentence completion test aimed at measuring child intelligence levels. Upon its completion in 1909, Ebbinghaus’ test marked the first prominent test of mental ability ever created. Variations of this test are still used in certain psychological evaluations today.

In addition to co-founding the Journal of Psychology and Physiology of the Sense Organs in 1890, Ebbinghaus also authored two highly influential psychology textbooks, The Principles of Psychology published in 1902 and A Summary of Psychology published in 1908. Later editions of these texts remain in contemporary circulation.

Forgetting Curve

Ebbinghaus' first significant study in this area was published in his 1885, Memory: A Contribution to Experimental Psychology. Ebbinghaus studied his own memorization of nonsense syllables, such as "WID" and "ZOF." By repeatedly testing himself after various time periods and recording the results, he was the first to describe the shape of the forgetting curve. The forgetting curve illustrates the decline of memory retention over time and is related to the concept of strength of memory which refers to the durability that memory traces in the brain. Throughout various experiments, Ebbinghaus discovered that the stronger one’s memory is the longer one can remember a given material.

Ebbinghaus discovered the exponential nature of forgetting, describing the formula of forgetting by

R = e(−t/S)


A typical graph of the forgetting curve shows that humans tend to halve their memory of newly learned knowledge in a matter of days or weeks unless they consciously review the learned material. In a typical schoolbook application of learning word pairs, most students show a retention of 90 percent after three to six days, depending on the material. In other words, during this period, the forgetting curve "falls" by 10 percent.

Ebbinghaus observed that the speed of forgetting depends on a number of factors such as the difficulty of the learned material, how meaningful the material is to the subject, representation of material, and other physiological factors including stress and sleep. His results showed the forgetting curve to be steepest for nonsensical material. The curve proved nearly flat for vivid or traumatic memories. According to Ebbinghaus, the flatness of the curve is not necessarily evidence for a decrease in the forgetting rate, but can be evidence of implicit repetition, or reliving memories, that indefinitely restore memory traces.

On average, Ebbinghaus found the basal forgetting rate to differ little between individuals. He explained the difference in performance, as measured in schooling, through mnemonic representation skills; while some people are able to "imagine" memories in the correct way, others are not.

Basic training in mnemonic techniques has been shown to overcome such differences. The best methods for increasing the strength of memory include the improvement of material representation with mnemonic techniques, and the increase of repetition based on active recall or spaced repetition. Each repetition in learning has shown to increase the optimum interval before the next repetition is needed. For near-perfect retention, studies have shown initial repetitions may need to be made within days, but can later be made after years.


Hermann Ebbinghaus’ lasting contributions to the field of psychology are multiple. In addition to being the first psychologist to study areas of human learning and memory, Ebbinghaus contributed greatly to the establishment of experimental psychology. Identifying both the "nonsense syllable" and the "forgetting curve," Ebbinghaus revolutionized the study of psychology to incorporate mathematical evaluation and experimental research into the study of higher cognitive processes in human beings. His most famous work, On Memory, launched an international awareness of the psychology field as well as the widespread use of experimental psychology in both research and study. While pioneering precise experimental techniques used in memory and learning, Ebbinghaus also established two psychology laboratories in Germany, co-founded a highly influential psychology journal, and promoted the international advance of psychological study in its earliest years.

Ebbinghaus’ work suggested that learning is more effective when it is spaced out over time rather than conducted during a single longer session. He also discovered that forgetting happens most rapidly right after learning occurs and slows down over time. These empirical findings have important consequences for pedagogical practice.

Major Publications

  • Ebbinghaus, H. 1987. Memory: A Contribution to Experimental Psychology. New York, NY: Dover Publications. ISBN 0486255557
  • Ebbinghaus, H. 1902. Grundzüge der Psychologie. Leipzig: Veit & Co.
  • Ebbinghaus, H. 1908. Psychology: An Elementary Textbook. New York, NY: Arno Press. ISBN 0405051387


External Links

All links retrieved September 11, 2013.


