First of all, the majority of human communication is language-based. That means it is symbolic in nature, dependent on vocabulary and grammatical structure of some sort, and it can be verbal or written. While humans can and do communicate through body language and scent, these types of communication make up a very small fraction of our net information exchange. Our communication can be about the past, present, or future, and can include abstract ideas and connections.
Most animals do not have the anatomical structure necessary for spoken language, and many species do not appear to have the ability to process symbolic information. Instead, animals generally rely on body language, limited vocal calls, and scent to communicate. As a result, their communications are always in the present tense and are about immediate real-world information such as status, food, territory, and availability to mate.
There are some exceptions to this. A number of primates, including gorillas and chimpanzees, have been taught American sign language, and have subsequently demonstrated basic grasp of symbolic language. Dolphins, which can communicate by sonar, appear to also be capable of symbolism.
In rebuttal of the statement that animal communication is inclusively instinctual and not learned, studies have been conducted with domestic dogs and wolves brought up in captivity around humans. While dogs that are pets watch the faces of humans and react according to their expressions, the wolves or wolf-mix dogs do not generally pay attention to the owner's expressions. Therefore, it seems safe to say that pet dogs have learned what certain facial expressions mean and they react according.
...a new study has found that dogs are able to tell the difference between happy and angry human facial expressions. (Related: "Animal Minds" inNational Geographic magazine.)
Of high intelligence on the scale of animals, dogs have learned from experience that certain reactions and voice level come from an owner depending upon the facial expression. They have also learned that certain behaviors of theirs elicit certain facial expressions and reactions from their owners.This fact is verified by biologist Corsin Muller of the University of Veterinary Medicine in Vienna Austria. In this study eleven dogs, among which were a fox terrier, border collies, a German Shepherd, a Golden Retriever, and several mixed breeds, were trained to touch a screen that had either a happy face or an angry face for a treat.
To ensure that the dogs were not simply responding to just a smile or some single expression, they were shown either top parts of a face or the bottom parts. The dogs were shown strange faces (the left side of the face was used as dogs seem to prefer looking at this side), yet the ones trained to identify happy faces were consistently able to do so. Other dogs were trained to select the angry ones. Interestingly, more training was necessary for the angry faces, possibly because the results of angry faces were negative (no belly rubs or treats); nevertheless, the dogs identified these angry faces.
While there may be no scientific proof, many a pet owner will adamantly assert that his/her pet communicates with him/her. For instance, one dog owner once had an intelligent mutt who "could not lie about her misbehavior." Whenever she had eaten something not intended for her or done something wrong, if the owner questioned her "Did you do this?" in a certain tone of voice, she would sit up, and make a unique noise, hang her head, and nervously tap her tail quickly on the floor. If she had not done the action under question she would not move her tail, and she looked straight at the owner. Her answers were correct 100% of the time, the owner asserted. Another owner of a horse spoke several times about how her horse seemed to intuitively know what she was thinking sometimes. For instance, she stopped during her ride one time to decide at a fork which path to take (she had never been there before). After a couple of minutes she decided. At the very moment at which she made up her mind, her horse, who had been munching on grass while waiting, suddenly jerked its head up and went toward the path which deviated from the one on which they had been; this was the one upon which the owner had decided. While scientists have contended that man has ignored his sixth sense so long that it is diminished, this horse seems to have it.
Like humans, animals have a system of communication which allows them to interact with each other in their environment. This form of communication, however, lacks the complexity of human communication and is basically useful for survival. For example, a bee dances around to show other bees the route to take in order to find pollen (food). But this particular bee could not describe to the other bees what flowers he saw along the way nor could this bee reflect on and assess the success of the trip and tell the other bees.
Human communication is learned, while animal communication is instinctive. A young animal does not have to learn from his or her parents the meaning of some calls used amongst their group; it comes naturally as even unhatched babies in eggs remain quiet when approached by predators. But a human offspring has to learn and be taught vocabulary, pronunciations and meanings of words through socialization from those around him or her. For instance, the boy raised by wolves was not able to communicate using vocabulary associated with human language and communication.