| Adriaan Kortlandt | |
| Birth Date: | January 25, 1918 |
| Birth Place: | Rotterdam |
| Death Date: | October 18, 2009 |
| Death Place: | Amsterdam |
| Nationality: | Dutch |
| Fields: | Ethology |
| Education: | University of Amsterdam |
| Doctoral Advisor: | Johannes Abraham Bierens de Haan |
| Known For: | Research on cormorants and apes |
Adriaan Kortlandt (January 25, 1918, Rotterdam – October 18, 2009, Amsterdam) was a Dutch ethologist. He has been described together with Vernon Reynolds and Jane Goodall as "...one of a trio of pioneers ... who founded field studies of chimpanzees in the 1960s."[1]
Adriaan Kortlandt was born on January 25, 1918, in Rotterdam, Netherlands. From a young age he was fascinated by animal behaviors, spending time observing cormorants near his home.
Kortlandt studied biology at the University of Utrecht, carrying out his PhD research at the University of Amsterdam on cormorant behaviors. After obtaining his doctorate in 1949, he researched avian instincts using field observation.
Kortlandt studied the instinctive behaviors of cormorants from a young age. His detailed observations pioneered new methods for studying animal behavior patterns in birds.[2] His work provided insights into the rigid nature of instinctive behaviors in cormorants and their importance for species survival. However, when Kortlandt suggested his findings could inform human psychology and medicine, it brought him into conflict with contemporaries like Niko Tinbergen. They believed animal behaviors should be studied as biological phenomena in their own right, not crudely anthropomorphized. This disagreement led Kortlandt to shift his focus to studying primate behaviors.
In 1940, both Kortlandt[3] and Tinbergen[4] independently identified[5] the behavioural phenomenon that is now called displacement activity (Dutch: overspronggedrag)and the hierarchy of instincts.[6]
In 1965, Adriaan Kortlandt conducted experiments with chimpanzees to understand the defense mechanisms of early humans against predators. He introduced a stuffed leopard electronic moving head to a group of chimpanzees. The chimpanzees responded by attacking the leopard using sticks and amplified their assault with loud screams and hoots. These observations, combined with the behavior of wild chimpanzees, indicated to him that early humans might have used objects like sticks and rocks for defense and attacked predators collectively.
In 1980, Kortlandt carried out experiments on the defense strategies of early small-posture hominids in collaboration with George Adamson. He tested ideas that thorn weapons might have deterred predators from early humans by putting meat under thorn branches and observing lion reactions.[7] Kortlandt also built a robotic model early human ancestor with movable thorns for arms. When experimentally placed near wild lions, they were frightened away by its jerky motions and whipping thorns. Kortlandt concluded even simple thorn branches could have helped early humans intimidate predators on the dangerous African savannahs.
He also was the author of the "Rift Valley theory",[8] better known under the name given by French paleoanthropologist Yves Coppens: "East Side Story".
WITH CHIMPANZEES IN THE WILD (1992) University of Amsterdam (Audiovisual Centre)