Science vs. Hollywood: Shark Experts Separate ‘Jaws’ Fact from Fiction

Released on June 20, 1975, Jaws chewed through the gritty, cerebral aesthetic of the “New Hollywood” of the late ’60s like it was a lone teenager taking a midnight swim—and left behind a thirst for summer movies that were thrilling, sequel-ready, and scored by John Williams.

Movie audiences watching a small-town police chief, an oceanographer, and an eccentric shark hunter pursuing a great white terrorizing a New England beach town also got their first taste of killer shark lore. Jaws taught those viewers that sharks were essentially mindless marine eating machines.

Conservationists and marine biologists even coined a term, “the Jaws effect,” for an exaggerated fear of the animals and apathy about their declining populations. In the five decades since the release of Jaws, overfishing has caused a 70 percent drop in worldwide shark populations. Thanks to Jaws’ masterfully Hitchcockian scenes, in which the antagonist is both a nearly invisible stalker and terrifying monster, “Save the Sharks” is a still tough sell as a bumper sticker. 

Fifty years after its release, we spoke with shark scientists to set the record straight. 

1. Myth: Sharks Have a Taste for Human Flesh 
2. Myth: Rogue Sharks Are the Serial Killers of the Sea
3. Fact: More Beach Visitors Mean More Shark Attacks
4. Fact: Tiger Sharks Are the “Garbage Cans of the Ocean”
5. Myth: Sharks Love to Take a Bite out of a Boat
6. Myth: Great Whites Grow to 25 Feet and Three Tons
7. Fact: Survivors of the USS Indianapolis Were Attacked by Sharks
8. Myth: The Indianapolis’s Mission Was Too Secret to Rescue the Men 
9. Myth: Sharks Want to Fight You

Myth: Sharks Have a Taste for Human Flesh 

First, let’s tackle the premise of Jaws: A particularly large, vicious great white shark on the prowl for human flesh near a beach town.

In reality, shark attacks on humans are incredibly rare. The Florida Program for Shark Research at the Florida Museum of Natural History finds that in an average year, there are 70 to 100 sharks bites on humans, resulting in about five deaths. That is globally. About half of the attacks are provoked by humans. Throwing chum from a boat, freeing a shark from a fishing net or trying to shove a GoPro in its face while scuba diving are considered provocations. 

“Shark bites are so astronomically rare that shows like [Discovery Channel’s] Shark Week have to recycle the same stories over and over again because there aren’t enough to otherwise fill a week of documentaries,” Dr. David Shiffman, a marine conservation biologist and science writer, tells Mental Floss.

And while sharks are flexible predators that view everything around them as possible food, humans are not appetizing. When compared to their usual food sources—like crustaceans, mollusks, marine mammals, and other fish—we land animals are lean and bony. 

“When they bite us, they almost immediately go, ‘Eww, what was that?’” Shiffman says.

That is one reason why a vast majority of the attacks documented by the Florida program are categorized as “hit and run.” The shark bites or slashes the person and swims off. 

Myth: Rogue Sharks Are the Serial Killers of the Sea

Chief Brody (Roy Scheider) references a mid-20th century theory about “rogue sharks” when he asks Hooper (Richard Dreyfuss) about a type of shark that “picks out an area where there’s food and hangs out there as long as the food supply lasts.” Hooper retorts, “It’s called territoriality. It’s a theory.”

At least, it was when Peter Benchley wrote his novel. Victor Coppleson, an Australian surgeon, popularized the idea in the 1950s. Coppleson wrote two books on shark attacks and claimed that, while most sharks acted “normally,” some “patrol a certain area.” Such a shark “must be hunted until it is destroyed.” 

The idea was dismissed by researchers in subsequent decades. “That’s not and has never been a thing. … Sharks simply do not behave that way,” Shiffman says. 

However, the idea of “problem individuals” recently resurfaced in shark research. For a 2023 paper, Eric E.G. Clua, a French veterinarian, examined mucus left from two separate shark bites in the Caribbean and found a high probability that the same perpetrator was responsible. In the same paper, Clua presented two other cases, one near Egypt and the other Costa Rica, in which divers had photo and video documentation of sharks attacks. Unique stripes, fin shapes and other features pointed to a serial attacker in each. 

In the case from Costa Rica, local divers were familiar with a certain tiger shark that sometimes approached them menacingly and named her Lagertha, after a mythic Viking warrior queen. In 2017, she allegedly killed a diver by tearing into their left thigh.

“These case studies provide some of the first evidence for the existence of ‘problem individuals’ among sharks,” Clua wrote. He has advocated identifying and targeting aggressive sharks as an alternative to the mass culling that some seaside localities have instigated after shark attacks; studies have not shown a consistent correlation between culling and lowering the already low probability of a future shark attack. 

Because of the harm caused by the Jaws effect, “problem individuals” are a touchy subject among shark researchers, says Dr. Chelsea Black, a research fellow at the University of North Carolina at Chapel Hill’s Institute of Marine Sciences. A death from a shark attack is less likely than a death by flu, sun exposure, fireworks, and other things that illicit less fear.

“So it's kind of like: what is the benefit other than curiosity on the scientist’s part?” Black tells Mental Floss. “But I do think people are apprehensive about looking into that.”

Fact: More Beach Visitors Mean More Shark Attacks

In the same conversation about rogue sharks, Brody says, “Before 1900, when people first starting swimming for recreation, before public bathing and resorts, there were very few shark attacks, cause sharks didn't know what they were missing.” 

His timeline is correct—but it says nothing about the nature of sharks.

The first well-publicized shark attacks occurred in the early 20th century; many scholars link the start of galeophobia to a spate of five well-publicized attacks, four them fatal, near New Jersey in 1916.

It is not like sharks suddenly discovered an irresistible new food source, like when the first Thai restaurant opens in your town. Sharks and humans just rarely came into contact before increases in population along urban coasts resulted in the creation of modern-day public beaches, Black says.

“You just have more people now living at the coast and using these resources” she says. “When you put it in proportion, to an increase in people using the water, there is no statistical rise in shark attacks.”

Fact: Tiger Sharks Are the “Garbage Cans of the Ocean”

The shark attacks in Jaws are initially blamed on a tiger shark, a species identifiable by their namesake stripes, caught by a fisherman and allowing unscrupulous Mayor Vaughn to declare the problem resolved before it could bite into tourist traffic. 

Hooper says tiger sharks are “very rare in these waters” and theorizes that it swam up the Gulf Stream after finding a Louisiana license plate in its stomach—alongside half a flounder, a burlap bag, and a paint can.

“Tiger sharks are the garbage cans of the ocean,” he remarks. “They eat anything.”

This is an accurate description of tiger sharks, says Black, but there is a reason they are not picky eaters.  

“Tiger sharks have the unique ability that not all shark species do, that they can actually invert their stomach,” she says. “They’ll throw up their entire stomach so it’s inside out and dispel everything that they've consumed, and then they can put their stomach back in, so they are less concerned about consuming something that is unconsumable, because they know that they can just throw it up.”

Black adds, “I’ve seen it happen. It’s quite shocking.”

And it is true that, while tiger sharks migrate as far as Canada, they generally inhabit warmer waters.

Myth: Sharks Love to Take a Bite out of a Boat

Brody and Hooper discover that the killer shark is still at large when they investigate a half-sunken fishing boat and find a shark tooth in its hull (plus a dead fisherman). This is the first of two instances in Jaws in which the shark attacks a boat.

Sharks do sometimes bite inanimate objects, Shiffman says. They “are not used to things being in their environment that aren’t food” and might mistake the noises made by nautical equipment, like engine propellers, for the sounds made by a prey animal.

“A key point here is that sharks don't have hands,” he says. “The way that they explore their environment is by biting.” 

As a result of using their mouths for everything, sharks often lose teeth and are constantly growing new ones. 

Myth: Great Whites Grow to 25 Feet and Three Tons

When the crew of the Orca finally sees the beast, Hooper estimates its girth, mutters a formula, and calculates that the shark is 25 feet long and weighs three tons (6000 pounds). 

“That’s very large and that shark would have to live a really long time to get to that length and size,” Black says. “Of course, I never want to say, ‘Oh, that’s impossible,’ because we discover something new about sharks every day. It's certainly possible.” But a great white shark of that size is “extremely unlikely.”

An average fully mature male great white is 11 to 13 feet long and weighs between 1500 and 1700 pounds. 

As for extremes in size: According to marine biologist and shark expert John Randall, the largest reliably measured great white, encountered near Ledge Point, Australia, in 1987, was 19.7 feet long. In 2020, scientists with the marine animal tracking organization OCEARCH discovered a female great white, known as Deep Blue, measuring 17 feet, 2 inches and weighing 3541 pounds. Earlier this year, OCEARCH documented a male, nicknamed the Contender, at 13 feet and 9 inches and weighing 1653 pounds.

And yes, marine biologists do have formulas to do napkin math on the size of an animal. One of the most famous is the von Bertalanffy growth equation.

Fact: Survivors of the USS Indianapolis Were Attacked by Sharks

One of the key scene in Jaws sees Quint (Robert Shaw), the grizzled professional shark hunter and captain of the Orca, explain his Ahab-like obsession with sharks to Brody and Hooper. He tells them that during World War II, he survived the sinking of the USS Indianapolis. As the surviving crew floated helplessly in the Pacific, Quint watched his shipmates picked off by sharks. “By the first dawn the sharks had taken more than a hundred,” he said, and continued chomping them to death at a rate of “six an hour.”

The sinking of the Indianapolis actually happened and left survivors stranded in a situation that was desperate even by the standards of a shipwreck. Sharks were there, too, but their role has been overstated.  

On July 30, 1945, Japanese torpedoes sank the heavy cruiser with 1196 men aboard. About 300 died in the initial attack. Survivors formed clusters, floating in the ocean, and clung to life vests and each other. They were plagued by dehydration, sun exposure, and injuries suffered during the torpedo attack. As time went on, hallucinations caused some to exhaust themselves trying to swim to an imagined shore; many drowned.

Over the course of five days following the initial torpedo attack, another 500 or so men perished, some because of sharks.

“In that clear water you could see the sharks circling. Then, every now and then, like lightning, one would come straight up and take a sailor and take him straight down,” one survivor told the BBC in 2013. Oceanic whitetip sharks, found in that area of the Pacific, are scavengers and may have been attracted by the blood and dead bodies.

Of the 890 total Indianapolis sailors who were lost, historians estimate the number of deaths from sharks at a few dozen and, at most, about 150—far fewer than Quint claims.

“The number of humans that Quint attributes to being killed by sharks in that one incident is more than the number of humans that are confirmed killed by sharks in the rest of the history of the world combined,” Shiffman says. 

Richard A. Hulver, a historian who headed the Navy’s USS Indianapolis Project, concurred: “Sharks certainly took the lives of men in the water, but historical records indicate that they fed on the dead more than the living.”

Myth: The Indianapolis’s Mission Was Too Secret to Rescue the Men 

Quint says that at the time of the sinking, the Indianapolis was returning from a mission delivering atomic bomb components to a U.S. naval base in the Northern Mariana Islands. “The bomb mission had been so secret, no distress signal was sent,” he says. For the same reason, the Navy failed to list the ship as overdue, delaying their rescue. He also says sailors could not free the lifeboats because they were lashed too tightly to make the ship faster for the mission. 

It’s true that the Indianapolis delivered atomic bomb components, a mission unknown to most of its crew. The rest is poetic license.

The Japanese torpedo attack was devastatingly quick and effective. Both torpedoes hit fuel tanks, creating explosions that instantly ripped the Indianapolis into pieces. The ship sank within 12 minutes. Crewmembers did not have time to get to the lifeboats. Radio operators sent distress signals, but equipment was badly damaged and it remains a matter of historical contention whether anyone ever received one. 

As for an alleged hush-up, Hulver pointed out, “The Indianapolis had delivered her cargo; her top-secret mission was complete” prior to the sinking. Afterwards, there was no reason for its movements to be any more secret than any other Navy ship.

Myth: Sharks Want to Fight You

The finale sees the trio aboard the Orca, locked in combat with the shark and trying to harpoon it as it attacks the boat and its occupants. Then the shark jumps out of the water to devour Quint.

Leaping out of the water, a.k.a. breaching, is a rare behavior for great white sharks, says Shiffman. It has only been observed in one location, False Bay off South Africa, where watching for “flying sharks” is a unique tourist draw. Researchers think this is due to the challenges of catching fur seals, quick and agile creatures capable to leading sharks on a chase.

The finale of Jaws is, by design, a thrilling climax, but Black says that humans can provoke aggressive behavior in sharks. She recounted her own experience near the Maldives while swimming among spinner sharks.

“For whatever reason, there’s one shark that I maybe startled when I jumped in. He just maybe happened to be there when I got off the boat. I startled him or something, and he did not like that, and he started circling me, and I know that’s an aggressive behavior and that the shark is uncomfortable with me.” 

She kicked the shark with a diver fin. As it circled around again, she prepared a punch to show she was “an equal predator” and not prey. But then, other sharks surrounded the aggressive one and she swam toward other humans. At that point, the shark likely saw the the threat Black posed as not worth further effort. 

It’s a language spoken by sharks and the humans who study them. Marine biologists speak it so well that most feel safe swimming among sharks.

“I have been in the water with hundreds of sharks all over the world,” Shiffman says, “and most of the photos I've taken are of sharks swimming away from me really fast, because that's normally what they do with most people.”

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