Sharks have, for many decades, been considered to be rather unintelligent;built and designed solely for hunting. Over recent years, though, scientists have begun to invest more interest in the lives and behaviour of these fearsome fish. As a result, it has been noted that, not only do sharks display a measure of intelligence, but they have frequently been seen expressing curiosity and even problem-solving skills. It has not yet been discovered what the body-to-brain mass ratio has to do with the intelligence of an animal, but the shark’s is similar to most birds and mammals.
In the past, there have been several reports of sharks having learned to recognise certain boats and divers, as well as having differentiated the front of a person from the back so that they can make a surprise attack behind them. Some divers have reported being mauled gently by a shark, in a way that showed an inquisitive exploration, rather than a full-on attack. A notable sight was the seven Great White Sharks that worked together at Smitswinkle Bay in South Africa to pull a large dead Pygmy Southern Right Whale into deeper waters before feeding on it. This suggests that these animals understood the theory of flotation, even if only in very basic terms.
Intelligence and instinct are two very different things. Instinctual behaviour is repetitive, in response to objects in the environment. It is deliberate (i.e. not a reflex), but does not require training and is common amongst all sharks of that species and / or habitat. So, a reflex would be the shark:©’s pumping water over its gill slits for oxygen, while instinct would refer to its rolling its eyes back when the snout is impacted.
When sharks become accustomed to feeding in a certain area, they no longer consider the bait to present a threat to their eyes;therefore this instinct lessens and may even stop. In contrast, regardless of circumstances and training, reflexes will never be halted. Intelligence, however, differs amongst individual sharks and is the linking of cause and effect. Even its ability to ascertain when instinctive responses are no longer necessary displays a measure of intelligence.
Their curiosity has been noted when two objects are placed in the water one resembling the shape of a seal, and the other a square. Because the square is a shape not often seen underwater, many of the sharks (Great Whites, in this case) approached this object out of curiosity, rather than the seal-shaped one. This is a phenomenon observed in several cases and experiments. The creature bumps and looks at the object, usually with no intention of doing it any harm.
Various experiments have also shown sharks to possess a memory. Certain stimuli have been used to signal the release of food and sharks learned to wait for these sounds or signals before returning to a certain area for their reward. This proves that sharks are teachable. Interestingly, in some of the experiments, sharks went for many months before being retested and they still remembered the stimulus and the result. In the wild, similar learning occurs when sharks are seen leaping out of the water to spot and catch birds.