When you train animals good and lovingly they, more generally than not, become worthwhile, valuable and trustworthy creatures. Scientists have done lot of research and have come to a conclusion that the smartness in animal is measured three aspects such as emotions, self recognition and language. When the first aspect, which is emotion, is considered, it has been found that chimpanzees tend react to emotions in a correct manner. It is quite obvious that chimpanzees react to emotions because they have genes that resemble human genes, and this resemblance is up to 98 percent.

Chimpanzee, sometimes colloquially chimp, is the common name for the two extant species of ape in the genus Pan. Chimpanzees make tools and use them to acquire foods and for social displays; they have sophisticated hunting strategies requiring cooperation, influence and rank; they are status conscious, manipulative and capable of deception; they can learn to use symbols and understand aspects of human language including some relational syntax, concepts of number and numerical sequence; and they are capable of spontaneous planning for a future state or event.

The brain of a chimpanzee has been measured at ~337 cc, ~393 cc, with a general range of 282-500 cc. Human brains, in contrast, have been measured as being 3 times larger, variously reported volumes include ~1,299 cc, ~1,158 cc, and averages of ~1330 cc.

Parrot. Studies with captive birds have given insight into which birds are the most intelligent. While parrots are able to mimic human speech, studies with the African Grey Parrot have shown that some are able to associate words with their meanings and form simple sentences. The brain-to body size ratio of psittacines and corvines is actually comparable to that of higher primates. One argument against the supposed intelligent capabilities of bird species is that birds have a relatively small cerebral cortex, which is the part of the brain considered to be the main area of intelligence in other animals.

However, birds use a different part of the brain, the medio-rostral neostriatum / hyperstriatum ventrale, as the seat of their intelligence. Not surprisingly, research has shown that these species tend to have the largest hyperstriata, and Dr Harvey J. Karten, a neuroscientist at the University of California, San Diego, who studied bird physiology, has discovered that the lower part of the avian brain is functionally similar to that in humans.

Dog. The domestic dog has a predisposition to exhibit a social intelligence that is uncommon in the animal world. Dogs are capable of learning in a number of ways, such as through simple reinforcement and by observation. Dogs can also learn by mimicking human behaviors.Research has shown that dogs are capable of interpreting subtle social cues, and appear to recognize when a human or dog’s attention is focused on them.

Psychology research has shown that humans´ gaze instinctively moves to the left in order to watch right side of the person’s face, which is related to use of right emisphere brain for facial recognition, including human facial emotions. Research at the University of Lincoln (2008) shows that dogs share this instinct when meeting a human being, and only when meeting a human being. As such they are the only non-primate species known to do so. Stanley Coren, an expert on dog psychology, states that these results demonstrated the social cognition of dogs can exceed that of even our closest genetic relatives, and that this capacity is a recent genetic acquisition that distinguishes the dog from its ancestor, the wolf. Studies have also investigated whether dogs engaged in partnered play change their behavior depending on the attention-state of their partner. Those studies showed that play signals were only sent when the dog was holding the attention of its partner. If the partner was distracted, the dog instead engaged in attention-getting behavior before sending a play signal.

Octopuses are highly intelligent, likely more so than any other order of invertebrates. The exact extent of their intelligence and learning capability is much debated among biologists, but maze and problem-solving experiments have shown that they show evidence of a memory system that can store both short- and long-term memory. It is not known precisely what contribution learning makes to adult octopus behavior.

An octopus has a highly complex nervous system, only part of which is localized in its brain. Two-thirds of an octopus’s neurons are found in the nerve cords of its arms, which have limited functional autonomy. Octopus arms show a variety of complex reflex actions that persist even when they have no input from the brain.In laboratory experiments, octopuses can be readily trained to distinguish between different shapes and patterns. They have been reported to practice observational learning, although the validity of these findings is widely contested on a number of grounds. The octopus is the only invertebrate which has been shown to use tools.

Rat. Because of the ability to learn, rats were early on investigated to see whether they may exhibit general intelligence like larger or more complex animals.

Robert Thorndike, for example, provided strong evidence for g in rats by the use of a variety of tests such as mazes, problem-solving tasks, and simple avoidance conditioning. Performances tended to correlate across tasks, with stronger associations found between mazes and problem-solving than with simple avoidance tasks. Thorndike also reviewed a dozen earlier studies which also suggested that the highest correlations are found between more complex problem-solving tasks. However, it should be noted that there were other contemporary studies that found split or near zero-order correlation matrices for other populations of rats across cognitive batteries.

Elephant. With a mass just over 5 kg (11 lb), elephant brains are larger than those of any other land animal. A wide variety of behaviours associated with intelligence have been attributed to elephants, including those associated with grief, making music, art, altruism, allomothering, play, use of tools, compassion and self-awareness. Elephants are believed to rank equally in terms of intelligence with cetaceans and nonhuman primates.

The elephant’s brain is similar to that of humans in terms of structure and complexity; the elephant brain exhibits a gyral pattern more complex and with more numerous convolutes, or brain folds, than that of humans, primates or carnivores, but less complex than cetaceans. However, the cortex of the elephant brain is “thicker than that of cetaceans” and is believed to have as many cortical neurons (nerve cells) and cortical synapses as that of humans, which exceeds that of cetaceans