Embodied Artificial LifeEditorial

A characteristic of a mature scientific field is its ability to generate scientific debates. Just think of Watson and Crick’s DNA discovery in the 1950s. Or what about the engineering achievement of constructing the Deep Blue computer that defeated the world champion chess player? Certainly, these advances have raised debates that go far beyond the boundaries of the fields of genetics and engineering. Without trying to compare to these great achievements, one can, however, note that, likewise, several areas within the artificial life field are able to raise debates outside the artificial life community. One of these areas is the artificial life approach to robotics. For example, a number of biologists accept robots as a tool to verify (or falsify) their hypotheses about animal control mechanisms, which are based on animal behavioral experiments. Often, researchers do animal behavior experiments and, based on these experiments, come up with hypotheses about the animal control mechanism. These hypotheses can then be verified or falsified by building an adequate robot, implementing the hypothesized control mechanism, and then observing if it can account for the behavior. If not, then biologists will go back to the animal lab and continue their behavioral experiments with the animals to come up with new, modified hypotheses. The majority of biologists might not accept this methodology, but the important fact is that the debate continues. The debate concerns the reliability of a robot as a model of the animal under study. In parallel, the artificial life community enjoys its own, similar debate: Can simulation of the real world be reliable, or is embodiment a necessity in order to gain understanding about life? The discussion about simulation versus embodiment is by no means new, and actually many researchers in both “camps” have been players in the other. For instance, some of artificial intelligence’s great theoreticians have previously tried to build robots. In the late 1950s, Minsky and others tried to build a ball-catching robot (derived from the initial wish to build a Ping-Pong-playing robot), and in the early 1970s, McCarthy tried to build an assembly robot (to assemble a television kit) [4]. Neither of the projects succeeded, and as is well known, both researchers have moved away from embodied artificial intelligence. A typical argument for going toward simulation has been that building real robots (apart from being difficult) is largely a question of technology: Intelligence could be implemented as a suitable information-processing system running