Imitation of Life: A History of the First Robots

 Renato M.E. Sabbatini, PhD

Or the history of how the unlikely marriage of behavioral sciences, physiology, mechanics and electronics generated for the first time artificial beings capable of adaptative behavior, thanks to the pioneer work of W. Grey Walter.

Artificial Life

At the end of the 1940s the renowned neurophysiologist Dr. W. Grey Walter, well known for his work on the electroencephalogram, was keenly interested in exploring an electromechanical model of simple reflexes displayed by all living beings. He was convinced that even organisms with extremely simple nervous systems could show complex and unexpected behavior. Dr. Walter had already acquired a reputation of an interdisciplinarian genius, acting as a pioneer and exploring interface between electronics and biology. The word "bionics", the marriage of these apparently disparaging areas had yet to be coined.

Unusually skilled in understanting and practising the merge of these two sciences, Dr. Walter had the insight of conceiving and creating the first autonomous robotic "animals", whom he baptized Elsie and Elmer (for ELectroMEchanical Robot, Light-Sensitive). They were two "tortoise" as he nicknamed them, after an "Alice in Wonderland" character.

From the mechanical and electronic point of view, they were rather crude. The "muscles" [that is, the motion devices] consisted of three wheels mounted in a tricycle-like vehicle, two being propulsion wheels and the other a steering wheel, each controlled by independent motors. The "sense organs" were quite simple: just a light sensor and an externally-mounted contact sensor. Energy was supplied by a common telephone battery, placed at the back of the assemblage. A plastic shell covered and protected the whole set.

The "nervous system" aboard this amazing creature was extremely "primitive": it consisted of an analog circuit with two vacuum tubes, which controlled the wheel motors and the sense of direction by means of information gathered by the sensors. The turtles "knew" how to perform only two actions: 1) to avoid big obstacles, retreating when they hit one and 2) to seek a light source. However, if the light was too intense the robot moved back instead of moving forward. (In behavioral terms, Dr. Walter created "phototropic animals" just the way moths are).

Find out some historical records of Prof. W. Grey Walter project.

Dr Walter's original hypothesis came true. The interaction between the "nervous systems" of his "tortoises" and the environment generated unexpected and complex behavior. They never exactly repeated the same behavior, but rather followed a general pattern, just like animals do.

For instance, Dr. Walter built a small hutch, where Elsie could enter and recharge its battery. At the top of the hutch he put a lamp. He immediately noticed that the turtles wandered a lot about the "room", but eventually they they would turn toward the hutch as the battery gradually lose power, in order to recharge them. Then they would leave again, scanning the environment for new light sources.

Dr. Walter also placed a lamp on the top of each turtle's shell and observed the appearance of a kind of "social behavior", that is, a kind of interaction between them as they danced around each other, in movements of attraction and repulsion, eerily evocative of mating and territorial behavior!

Observing this, an astonished Dr. Walter wrote that "he noticed uncertain, randomic, free-will or independent characteristics [which constituted] aspects of animal behavioral and human psychology". Moreover, he added: "despite being crude [the tortoises} conveyed the impression of having goals, independence and spontaneity".

Owing tho this exploratory, speculative behavior of the robots in relation to the environment, Dr. Walter considered them a new "animal species" and coined the scientific name Machina speculatrix In a second series of experiments, the scientist created turtle-robots capable of learning, which he, once again, baptized with the name of Machina docilis ("machine capable of being tamed"). This machine learned to associate a whistle with a light, behaving just like Pavlov's proverbial dog, scanning for sound instead of light!

Due to these investigations, W. Grey Walter came to be considered as one of the "founding fathers" of cybernetics, the new science beingcreated by Norbert Wiener and Warren McCulloch in the USA, at the time. His turtles were among the first robots and constitute an example of what we call today Artificial Life, since they were the first mechanical beings having some of the typical properties of living beings, such as behavior and self-organization.

Therefore, it was only natural that Dr. Walter would attract much attention from the press, generating a huge interest and big controversies. He received letters from people who wanted to adopted Elsie and Elmer as their home pets. Dr. Walter himself told that he developped a certain kind of affection towards "these little beasts", that seeem to have a personality of their own.

W. Grey Walter's kind of autonomous robot has had its modern followings, as we will see below. The Mars rover, Sojourner I, is one of them. There are even "personal robots" which can be bought, such as Cye, which follow the same phylosophy of Elsie and Elmer

As we'll see next, many people think that a robot has a human nature... First, however, let's take a closer look at this formidable human invention and the potential it offers to replace work and intelligence by means of machines.

Next: W. Grey Walter: Machina speculatrix

To Know More

  1. Walter, W. Grey - A machine that learns. Scientific American, 184(8): 60-63, August 1951.
  2. Walter, W. Grey - An imitation of life. Scientific American, 182(5): 42-45, May 1950.
  3. Walter, W. Grey - The Living Brain, W. W. Norton, New York, 1963.
  4. Sabbatini, R.M.E. - Vida artificial. Correio Popular, Caderno de Informática, 22/07/97
  5. Sabbatini, R.M.E. - Robô não é gente. Correio Popular, Caderno de Informática, 05/08/97. [In Portuguese]
  6. Sabbatini, R.M.E. - Um robô no seu futuro ?. Correio Popular, Caderno de Informática, 19/09/1995. [In Portuguese]
  7. Turkle, S. - The Second Self: Computers and the Human Spirit.
  8. Walter's world. New Scientist, 25/7/98.
  9. Machina speculatrix: W. Grey Walter's history and how to reproduce Elsie using Lego. URL:
  10. Holland, O. - The Gray Walter Archive On-Line. University of West England. URL:
  11. Tamagotchi Central:
  12. Tamagotchi Fever:
  13. Robot Control Based on Neural Networks (CONNY) - European spatial robots project.
  14. Virtual Reality Models of the Mars Rover (NASA):


All pictures used in this article are copyright of the Burden Neurological Institute, Bristol, UK. Our thanks to Dr.  Owen Holland, University of West of England, UK, who has done a wonderful job in providing this and other interesting information about Dr. W. Grey Walter in his on-line archives.

About the Author

Renato M.E. Sabbatini has a doctoral degree on neurophysiology of behavior by the University of São Paulo, Brazil, and was visiting scholar of the Max Planck Institute of Psychiatry, Munich, Germany. Dr. Sabbatini is currently researcher and associate director of the Center for Biomedical Informatics of the State University of Campinas, São Paulo, Brazil, where he is the leader of research groups on Artificial Intelligence, neural networks and the applications of Internet and telemedicine to health.
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Versão para o inglês: José Valter Arcanjo da Ponte, biólogo com DEA em fisiologia vegetal pela Universidade de Paris VII, França. Atualmente é Pesquisador Associado do Núcleo de Informática Biomédica.

Copyrigt 1999 Renato M.E. Sabbatini
All Rights Reserved
First Published: July 25th 1999