Is the White Shark Intelligent?

Many people pride themselves on being intelligent, yet most have no clear idea of what they mean by that term. We recognize that there are different degrees of intelligence, ranging from moderate to extreme, although we find it very difficult to measure this quality in a way that everyone can agree upon. And most of us accept that, although clearly not as clever as ourselves, certain animals - such as dolphins, monkeys, octopuses, and at least some dogs - show signs of intelligence, whatever that is.

Defining intelligence is not easy. The challenge becomes particularly difficult if we attempt to define this elusive quality in a way that facilitates comparison across species boundaries. But if we are to tackle the question of White Shark intelligence, we must begin with at least a working definition of that slippery concept. I would suggest that, at its crux, 'intelligence' is the faculty of understanding the relationship between cause and effect. In practice, intelligence often involves making a choice from among several options by drawing upon experience to make judgments about likely consequences. The efficiency with which an animal can apply its past to shape its own future in ways desirable to itself is thus an index of intelligence. In evolutionary terms, the intelligence of animals can be measured and compared in terms of speed (how long it takes to make decisions) and adaptive fitness (the number of copies of an animal's genes that survive into future generations as a result of the sum-total of its decisions). The faster and more adaptively an animal can make such decisions, the more intelligent it is.

White Shark  ReefQuest Centre for Shark ResearchAs far as I know, this definition of intelligence is original with me. And although it may seem a fairly good attempt to define a complex and subtle concept in theory, it is extremely difficult to apply in practice. For example, not all decisions are of a simple either-or type; some are mind-bogglingly complex, involving the careful weighing of many factors and options before a decision likely to yield 'desirable' results can be reached. Therefore, comparing the number of units of time it takes an animal to arrive at decisions of different complexity - even assuming we can understand all of the parameters, sub-decisions, and implications involved - is all but meaningless. Further, it is extremely difficult to trace the reproductive consequences of a wild animal's decisions. While it is fairly easy to trace human descendants and captive animals from virtually any pair of biological parents, this is much, much harder to do in the wild. It is conceivable that, sometime in the future, it may be possible to model all decisions as a series of binary options and to track the genetic legacy of any wild animal parent. But until such methodologies become available, my definition is not terribly helpful toward measuring the intelligence of the White Shark.

Fortunately, there are some generally agreed-upon correlates of intelligence that we can compare across species boundaries. Two physical correlates of intelligence are the relative size and complexity of the brain. Per unit of body mass, the White Shark has a rather small - but very differently-wired - brain compared with that of humans, and a medium-sized, moderately-developed brain compared with that of most sharks. Because we understand relatively little about how the physical structure of the brain affects decision-making processes, we cannot meaningfully compare the brains of sharks and humans, nor can we knowledgeably compare the decision-making mechanisms among various sharks.

The behavior of an animal is often the only indicator we have of what goes on in another creature's mind. Unfortunately, like other sharks, the White Shark is very difficult to study in the wild. And since sharks generally behave oddly in captivity - and the White Shark, in particular, has never been successfully maintained in an aquarium for more than a few days - we have little more to go on that a few, scattered anecdotes. Yet those anecdotes are highly suggestive that the White Shark often behaves in ways that are, by my working definition, intelligent.

So, what can we conclude about the 'intelligence' if the White Shark from reports such as these? Only that this species seems to possess curiosity and a sense of exploratory play, the ability to investigate novel objects in an apparently systematic way, a keen sense of caution and quickly learns to avoid unpleasant stimuli, it can learn to recognize inedible objects and not waste effort in trying to eat them, it has a sense of property and will defend a food resource in an oriented, apparently calculated - but non-violent - way, and may even co-operate to enable group members to maximize their feeding efficiency.

If I am interpreting these reports correctly, it is not hard to conceive how such responses could be adaptive. Balancing curiosity with caution seems a prudent means to increase the likelihood of surviving long enough to breed successfully. The ability to explore novel objects and to learn which are edible and which are potentially harmful may lead to a richer, more varied, and therefore more reliable diet. Because reproductive success in sharks is directly related to feeding success - with better fed individuals generally attaining maturity at an earlier age and having larger litters of bigger pups, which are themselves better able to survive than smaller pups - being better able to be feed and avoid danger can be expected to result in greater genetic representation in future generations.

So, is the White Shark 'intelligent'? Based on the evidence available to me at present, I just don't know. In its own way, it probably is. After all, White Sharks have been successfully making a living in the single largest interconnected living space on our planet for more than 10 million years. In contrast, our species has only been around for perhaps 1/100th as long - and in that time (among some very laudable and even noble achievements), we have been able to pollute our environment, devise ever more elaborate ways to save time that we don't quite know what to do with, and repeatedly use our cleverness to cheat, abuse, or kill off one another at a profligate rate. Now I ask you: is that intelligent?

 

ReefQuest Centre for Shark Research
Text and illustrations R. Aidan Martin
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