In 1985 I began a long-term project in the Bahamas to observe and study, underwater, a resident group of Atlantic spotted dolphins, Stenella frontalis. Over the last 16 years we've recorded life history information, communication (visual and postural) signals during fighting, foraging, and play, and how mothers teach their calves to hunt, fight, and babysit younger dolphins. The richness of behavior we've observed over 16 years at sea speaks of a culture of intelligent aquatic beings, with complex communication and flexible coping strategies in the world. Dolphins are the aquatic equivalent of an advanced terrestrial culture. Such observations reinforce the idea that perhaps dolphins would be good candidates with the motivation to interact with, and potentially communicate with humans.

   The possibility of communicating with nonhuman animals has long fascinated humans as long ago as Aristotle. Interspecies interaction, specifically human/dolphin, is a very old phenomenon but a reemerging field of scientific inquiry. The more we inquire into the lives and minds of dolphins, and other toothed whales, the more we find evidence of complex societies, communication, and cultures. Only recently have we begun to search in the wild for such evidence and opportunities to work. This interest stems from years of exploring the possibilities of communication with other species, usually in non-wild environments.

   Many of our popular beliefs about dolphins come from the work and writings of John Lilly. Originally a neurophysiologist with an interest in the dolphin brain, Lilly began to understand that dolphins were too intelligent to experiment on, and forged his own path to interspecies communication. Although his later work remains controversial, many of his original ideas remain intriguing. Lilly pursued a controversial career, trying to teach dolphins English and matching vocal output by the dolphins to humans. Although able to mimic the prosodic aspects of human speech such as rhythm and intensity, the dolphins were unable to produce consonants involved in the production of English sounds, most likely due to the lack of necessary anatomy.

   Since Lilly's time a picture has emerged from long-term research projects around the world. Ken Norris and his colleagues in Hawaii have studied spinner dolphins, Stenella longirostris, Randall Wells and his colleagues in Sarasota, Florida continue to study bottlenose dolphins, Tursiops truncatus, and my ongoing work in the Bahamas studying Atlantic spotted dolphins, Stenella frontalis. We know many realistic aspects about life as a dolphin in the wild both biologically and ecologically. But what will it really take to break the code, to build a bridge between species, in this case an aquatic mind evolved over a 30 million year old aquatic in a socially complex environment?

   In captive settings, giving the dolphins control over the choice of reinforcement and social interaction with nonhuman subjects has been paramount in the investigation of interspecies communication. Success has often been determined by the selection of the appropriate sensory modality within which to communicate and work. Participatory research, in combination with observations of a species natural communication system, may be a fresh method of investigation available to us.

   We can see parallels from primate researchers over the years who have focused on training their nonhuman subjects with artificially derived codes. This mutual system of approach, or two way communication methodology, has often been chosen because of the difficulty of comparing and deciphering the complexities of nonhuman natural systems.

   In the history of work with captive primates there is a continuum of methodologies researchers have used, from very objective and strict, to more interactive, involving bonding with the animals under study. One of the first studies, by David Premack, was a chimpanzee named Sarah who was acquired from the wild. She was trained with the use of a board, testing her ability to discriminate "same and different" objects. Premack used an interrogative concept and remained separate and "objective" during his work with Sarah. His work could be considered on the far end of the continuum.

   Duane and Sue-Savage Rumbaugh brought an interactive approach to their work with two other chimpanzees, Sherman and Austin. The researchers invested time developing rapport with Sherman and Austin, and also tried to develop experiments that included referents or objects that were important to chimpanzees themselves. Allowing Sherman and Austin to work as a team, possibly mimicking the way communication systems evolved under natural conditions, was also very successful. In later years they started working with Kanzi, a pygmy chimpanzee, the most closely related primate to humans. Using a portable keyboard and a semi-natural environment, Kanzi is skilled at understanding complex symbolic associations.

   Another innovated approach to interspecies communication has been the work with chimpanzee Washoe. The key to this work was trying sign language, which Alex and Beatrice Gardner, and then Roger and Debbie Fouts, believed was close to the chimpanzees' natural gestural abilities. Washoe could express herself with gestures and this proved the key to the interspecific communication between chimpanzees and humans. Roger Fouts also reasoned that the chimpanzees would be much more interested in working with humans if they liked them and found them interesting. This would provide the social motivation for expressing themselves, to communicate with someone they liked, about something they desired or wanted to express. His study would later document the spread of sign language from chimp to chimp, without human intervention, as an example of cultural transmission within the chimp society itself.

   Some of the controversies around nonhuman animal communication has centered around the "Clever Hans" story. Clever Hans was a horse that was taught to "count", among other skills, by his trainer. When a psychologist observed this interaction, he noticed that the trainer was giving Hans subtle cues, everything from face nods to slight movements. Without these "cues", Hans could not perform properly. When the "double blind" method, not allowing the trainer or experimenter the knowledge of the answer, was applied to avoid the suspected exchange of subtle cues from trainer to animal, Clever Hans could not perform.

   What does the Clever Hans phenomenon suggest about biological communication in general? Could it be that these "cues" are information bits that create complex communication in the first place? If so, then we are asking nonhuman animals to do what we cannot; to be restricted to one modality, such as gestural signs or acoustic cues, and learn a multi-modal language that involves these exact subtle cues. This perhaps, could be our biggest lesson about communication and might result in the creation of a more interactive and functionally expressive methodology for interspecies communication in the future.

   Despite the continuum of methodologies in all primate interspecies work, most researchers agree that creating rapport with nonhuman subjects is critical to the animal's motivation for interacting and expressing themselves. Other species are capable of interacting and communicating on a variety of levels. Perhaps it is our human challenge to develop methodologies and sensitize ourselves to the motivation of other species to maximize our opportunity to make a connection.

   Perhaps the similarities we find between species may turn out to be more critical than the differences. We might find levels of mental and social continuity and convergence across social species on our very own planet, Earth.