In The Shallows, Blake Lively plays Nancy, a young surfer who gets caught in a game of cat and mouse with a great white shark just a few hundred yards from shore. From the moment of the initial bite, the villainous shark zeroes in on Nancy, circling her in the water even as she finds safety on a rock in the shallow waters — hence The Shallows. Granted, the shark's unrelenting pursuit of Nancy is pretty much the entire point of the movie, but it is awfully suspect. Do sharks really zero in on prey so intently? Does this shark truly have nothing better to do than to wait for Nancy to become his dinner? Really, do sharks have personalities that would cause them to have such intense behavior? After all, the shark in The Shallows seems truly obsessed with making Nancy his dinner.
The Shallows certainly makes you think that sharks have personalities — specifically the murderous kind. Yet in real life, sharks don't generally like to eat people. National Geographic reports that research suggests that most shark attacks committed by great whites are actually test bites, where sharks take a taste of something they think might be a seal or other foodstuffs. Generally, after a shark has bitten a human, they're unlikely to come back for more. So why does the shark in The Shallows seem incapable of leaving Nancy alone? The answer could be that the problem isn't that the shark is hungry, but rather that he wants to kill Nancy.
New studies suggest that individual sharks have different personalities, just like humans. In 2016, the Journal of Fish Biology published a paper that hypothesized that sharks have different personalities, specifically when it comes to their level of boldness or "propensity to take risks," New York reports. The paper detailed a study that compared how different sharks reacted to being enclosed in a small tank, and how quickly they were able to escape. Some sharks freed themselves much quicker than others and appeared to be more active in trying to find an escape, suggesting a higher level of boldness than those that took a calmer approach.
The difference among the sharks studied, the paper claims, could be proof that sharks have different personalities — that their response to stress is not instinctual or the same across the board. "The main thing that emerged from this work is that each shark is an individual, with predictable behavioral responses to certain events," said Dr. Culum Brown in an interview with Australian Geographic, one of the leaders of the study.
Not all sharks would hunt humans like the shark in The Shallows, but it seems that Nancy also got very, very lucky.