Animal intelligence has always been a captivating and often debated subject. From pondering the cleverness of dog breeds to marveling at the human-like capabilities of chimpanzees or the problem-solving skills of octopuses, we continuously seek to understand the cognitive abilities of creatures around us. Among these fascinating species, dolphins consistently emerge as exceptional candidates for high intelligence, often sparking the question: just How Smart Are Dolphins Compared To Humans?
Indeed, dolphins are frequently cited as the second most intelligent animals on our planet, trailing only humans – or perhaps, as humorously suggested by Douglas Adams, humans might just be in third place.
“Man has always assumed that he is more intelligent than dolphins because he has achieved so much — the wheel, New York, wars and so on — while all the dolphins had ever done was muck about in the water having a good time,” the renowned science fiction author Douglas Adams wrote in So Long and Thanks for all the Fish. “But, conversely, the dolphins had always believed that they were far more intelligent than man — for precisely the same reasons.”
Humor aside, there’s substantial evidence to support the notion of remarkable dolphin intelligence. These marine mammals possess sophisticated language skills and demonstrate an impressive ability to learn complex behaviors, even performing in television shows. Dolphins have been utilized by both the U.S. and Russian navies, and while the claim that they can detect cancer remains scientifically unproven, their capabilities are undeniably significant.
:max_bytes(150000):strip_icc():format(webp)/dolphins-jumping-out-of-water-58a7b3595f9b58a3c9257c49.jpg)
“They exhibit culture, employ tools, and live in intricate societies,” emphasizes Neuroscientist Lori Marino, president of The Whale Sanctuary Project, who has dedicated three decades to studying dolphin brains and intelligence. “Their social complexities, behaviors, and level of self-awareness make these animals remarkably similar to us in many ways.”
Unpacking Brain Ratios: What Does Size Really Mean?
So, what fuels the argument for dolphins being exceptionally intelligent, possibly second only to humans?
A key factor often considered is relative brain size. Sperm whales boast the largest brains on Earth, weighing up to 20 pounds, according to the American Museum of Natural History. However, sperm whales are enormous creatures, requiring considerable brainpower simply for basic bodily functions like movement.
In a groundbreaking 2002 study, Marino and her colleagues delved into the encephalization quotient – the ratio of brain size to body mass – in dolphins. Comparing dolphins to other highly intelligent species such as chimpanzees, humans, gorillas, and orangutans, the study revealed that humans topped the list, closely followed by several dolphin species: Tuxuxi, white-sided, common, and bottlenose dolphins. Intriguingly, the encephalization quotient of these dolphins approached that of Homo habilus, a close human ancestor, and significantly surpassed that of sperm whales.
“Their brains are disproportionately large,” Marino explains. However, she also points out a growing consensus among researchers to move away from solely ranking animal intelligence based on brain size. Octopuses, for instance, may not score as high on the encephalization quotient scale, yet they demonstrate remarkable problem-solving capabilities in various experimental settings.
Bottlenose dolphins possess a high encephalization quotient, indicative of significant brain development relative to body size.
Hans Thewissen, a professor at Northeast Ohio Medical University specializing in cetacean evolution, notes that the evolutionary path towards larger brain size in whales and dolphins began around 33 million years ago during the Eocene Epoch. Another significant increase occurred in the early delphinids, the ancestors of modern dolphins, porpoises, and belugas, approximately 27 million years ago.
While brain size alone isn’t the sole determinant of intelligence, Thewissen suggests that this evolutionary leap in delphinids and other cetaceans likely coincided with the development of echolocation, a sophisticated hunting technique.
Dolphins: A Reflection of Our Own Cognitive Landscape
Understanding dolphin intelligence often requires us to reflect on our own human-centric perspectives.
“We’ve recognized their intelligence for millennia,” Marino states, noting observations of dolphin curiosity dating back to ancient Greece.
The first serious scientific investigations into dolphin intelligence emerged in the 1950s and 1960s, spearheaded by John Lilly, a scientist who studied bottlenose dolphin vocalizations. Lilly’s pioneering work laid the foundation for subsequent research into dolphin brains and cognitive abilities.
However, Lilly’s legacy is complex, as the ethical concerns surrounding some of his experiments overshadowed his contributions and, for a period, hampered serious dolphin intelligence research, according to Marino. Lilly’s association with counterculture figures and psychedelic drug experiments, including administering LSD to dolphins in an attempt to communicate with them, further complicated his scientific reputation.
Despite this historical detour, research into dolphin intelligence eventually resumed. Groundbreaking research published by Marino in 2001 demonstrated that dolphins possess self-recognition in mirrors. By marking dolphins’ bodies with spots and observing their reactions to mirrors placed in their tanks, Marino and her team confirmed that dolphins, like only a handful of other species including chimpanzees, exhibit this advanced form of self-awareness.
“This discovery marked the first time cetaceans were shown to possess this capacity, previously believed to be exclusive to humans and our closest relatives,” she explains. “It’s a trait absent in the vast majority of animal species.”
Further studies have revealed dolphins’ capacity to learn and comprehend basic human-created symbols and even complex sentences like “bring the ball to the hoop.”
“They grasp syntax,” Marino emphasizes. “They understand that ‘bring the hoop to the ball’ is different from ‘bring the ball to the hoop.’”
However, a significant limitation of many intelligence tests conducted on dolphins is their confinement to captive environments. While human curiosity drives the study of dolphin intelligence, this curiosity sometimes manifests in exploitative ways, from dolphin shows in aquariums to military applications.
Captive settings fail to replicate the natural environments in which dolphins evolved and thrive. Assessing dolphin intelligence through human-designed lab tests may not accurately reflect their cognitive prowess in navigating the challenges of their natural world. This realization has led Marino to shift her focus away from captive dolphin research.
“Much of the truly fascinating work is now happening in the wild,” she notes.
Studying dolphin behavior in the wild presents greater complexities, yet researchers have observed a wealth of intelligent behaviors in these cetaceans. Bottlenose dolphins off the coast of Western Australia have been documented using sea sponges as tools to protect their snouts while foraging for fish on the seabed. Others employ “mud nets” to encircle and hunt fish. In Brazil, dolphins have even developed cooperative hunting strategies with local fishermen.
Intriguingly, wild dolphin observations have also revealed some seemingly human-like quirks. While the intent remains unclear, dolphins have been seen interacting with pufferfish, seemingly entering a trance-like state of intoxication after presumably ingesting the potent neurotoxins produced by these fish.
Wild dolphins demonstrate sophisticated hunting techniques, such as creating mud nets to trap fish.
“Dolphins demonstrate that there isn’t just one form of complex intelligence on this planet,” Marino concludes. Their intelligence, while different from our own, is undeniably sophisticated and worthy of continued exploration and respect.
