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The human brain is the biggest by far. It weighs about three pounds (1.4 kg) and measures roughly 12 inches long x 8 inches wide. This makes our brain more than twice as heavy as any other animal’s brain.
Elephants have one of the most powerful brains among land mammals. They can weigh up to 1,200 lbs (544 kg). Their brains are about the same size as ours, at around 3 lb (1.4 kg) when it comes to comparison with the body weight.
A dolphin has a brain that is only slightly larger than ours. A whale’s brain is even bigger.
A shark’s brain is also very large but not nearly as big as a mammal’s. Its brain is about 2/3rds the size of a human’s.
But some fish have really huge brains. Some species of catfish have brains that weigh as much as 4 pounds which can be considered gargantuan, given their body weight.
Although the major measurement of a brain and coining it as big or small is done on the basis of the brain size in comparison to the bodyweight, let’s have a look at the animals that have the biggest brains, regardless of the bodyweight vs. brain size comparison.
1. Sperm Whale
A sperm whale has the largest brain of all living creatures. It weighs about 5,000 lbs (2,268 kg), making its brain about 7 times heavier than an average human being.
It has a brain volume of about 6,500 cubic feet (180 m³). That is almost two-and-a-half times the size of a Boeing 747 jumbo jet!
A sperm whale’s brain weighs about 10% of its total mass. In humans, this ratio is closer to 20%.
This means that if we were to compare the sizes of a human brain and a sperm whale brain, we would find that the latter is about five times smaller.
However, the fact remains that the biggest brain belongs to a whale, all because of their huge body size and weight.
Dolphins come next on our list of animals with the biggest brain. Dolphins belong to the order Cetacea.
Dolphin brains are comparatively very large compared to their body size. This is because they have evolved to hunt by sight rather than smell.
The average brain size of a bottlenose dolphin is between 0.5 and 0.8 lb (0.23–0.35 kg).
Like killer whales, dolphins have three sections to their brains. However, unlike killer whales, dolphin brains are not separated by lobes. Instead, they are connected via a single lobe. This connection allows for more efficient communication between different areas of the brain.
The largest dolphin brain found so far belonged to a female Atlantic spotted dolphin. Its brain weighed in at 0.84 lb (0.39 kg). This made it 1/3 larger than the previous record holder. The brain of this dolphin was about 17% bigger than the average dolphin brain. That said, the average brain size of a dolphin is much lower than what you might expect.
Elephants are one of the animals that have the biggest brain. Their brain is about the same size as a human head.
An elephant’s brain can weigh up to 2.5 kg (5.5 lb). The average brain size of an adult Asian elephant is around 1.4 kg (3 lb). However, the brain size varies depending on the age of the individual. A baby calf’s brain is only half the size of an adult’s brain.
An elephant’s brain is divided into three parts: the cerebrum, the diencephalon, and the telencephalon. These three sections make up the forebrain. Elephants have a massive cerebral cortex. This region of the brain has many folds. Each fold contains thousands of neurons. These neurons allow elephants to think creatively and solve problems.
The cerebrum contains most of the gray matter. It also has two lobes. The left lobe controls the right side of the body, while the right lobe controls the left side of the body.
The diencephalon is located above the cerebellum. It consists of four major structures: the thalamus, hypothalamus, epithalamus, and tectum.
The telencephalon is located below the cerebellum. There are two main divisions within the telencephalon: the olfactory bulb and the cerebral cortex.
The olfactory bulb is responsible for processing smells. It is where the sense of smell originates.
The cerebral cortex is responsible for higher-order functions such as memory and thinking.
Bats are one of the animals with the biggest brain relative to its body size.
A bat’s brain weighs about 0.1 oz (3 g) or less. Bats are nocturnal creatures. As such, they spend the majority of their time sleeping.
This means that bats don’t need to eat as frequently as other species. Because of this, bats can store fat reserves in their bodies.
This allows them to survive long periods without food. When they do get hungry, they go out looking for insects.
They use sonar to find their prey. Sonar works by sending out high frequency sounds. These waves bounce off objects in front of the bat. The echoes return to the bat’s ears. By analyzing these returns, the bat can determine the distance to the object.
In addition to using sonar, bats also use echolocation. Echolocation involves emitting low-frequency sounds. These waves reflect off objects in front of them. The returning echo helps the bat locate its prey.
Unlike humans who use both eyes and ears to see and hear things, bats use just their ears. They have large ear flaps that act like wings. These flaps help the bat control how sound travels through the air.
Humans have one the biggest brains among all living beings. Our brain weighs between 1.2 – 1.5 lbs (500 – 660 grams), making us the heaviest land animal.
Our brain accounts for about 2/3rds of our total body weight.
Our brain is made up of the cerebrum, cerebellum, and pons. The cerebrum makes up the largest part of our brain. It is responsible for controlling motor skills, sensory perception, speech, and thought processes.
The cerebellum is a small structure at the base of the brain. It coordinates movement and balance.
The pons is a bridge connecting the cerebrum and medulla oblongata. This area is involved in hearing, balance, and coordination.
6. Killer Whale
Killer whales are also known to have the biggest brain relative to their body size. Their brain weighs around 3.4 lbs (1.5 kg).
Their brain is divided into three parts: the forebrain, midbrain, and hindbrain. The forebrain is responsible for emotions, personality, and language. The midbrain controls vision, balance, and hearing. The hindbrain controls reflexes, sleep, breathing, and heart rate.
Does Having Bigger Brains Mean Smarter Species?
No brain size is not related to smartness. There are many factors that affect intelligence.
However, there are some studies that suggest having a bigger brain does make you more intelligent.
There are two main theories on why larger brains might be better. One theory suggests that having a larger brain increases your ability to learn new information.
Another theory suggests that having a bigger brain allows you to process information faster.
However, this has been disputed because it doesn’t explain why smaller species such as mice have big brains. It is believed that smartness or intellectualism is mainly measured by the evolution of the prefrontal cortex.
This region of the brain is associated with higher-order cognitive functions including planning, reasoning, decision-making, impulse control, self-awareness, empathy, and social behavior.
A study published in 2013 found that the size of the human prefrontal cortex increased over time. Other research has shown that the size of the prefrontal cortex correlates with IQ scores. A study conducted in 2010 showed that the size of the frontal lobe was positively correlated with verbal IQ.
A study published in 2011 found that the size of a person’s prefrontal cortex was negatively correlated with their performance on tests measuring spatial attention and working memory.
Therefore, the biggest of brains do not mean the smartest of animals. Therefore, if you were wondering if the sperm whale, having the biggest brain is smarter than humans, then you can stop wondering.
Which Primate Species Are The Smartest?
Following is a list of the smartest primate species:
Gorillas are native to Africa and are often regarded as symbols of power and strength. These mighty beasts of nature are capable of lifting over 300 times their weight without difficulty. Due to this strong muscle mass, their brains are relatively larger than that of humans.
Gorillas are members of the great apes—they are closely related to us, therefore they are similar enough to understand how we think, feel, and perceive the world. They are also smarter than gorillas, having a larger neocortex—the part of the brain responsible for thought processes.
Baboons are known to be quite clever. Researchers have found baboons to be able to remember images after a brief period of time. Also, they have been observed to plan ahead and understand what others will do next.
Like humans, baboons travel in complex societies, where they communicate using both vocal and non-verbal cues. So being social animals, it’s no surprise that their frontal lobes are much bigger than what we might expect.
Orangutans are considered to be close relatives of gorillas and chimpanzees. Despite being so different in appearance, they share much of the same behavior. A study suggests that they communicate using facial expressions, gestures, and vocalizations, like laughing calls. Orangutans live in small family groups, and females generally become mothers between the ages of 4 and 7 years old.
Orangutans are known as the happy ape, particularly due to their playful personalities. On the inside though, their braincases are proportionately larger than our own. This is due to the increased cerebral cortex area and sensory perception, allowing them to thrive in their environment.
Chimps are probably the best-studied primates in human history. They have been taught sign language, had electrodes attached to their brains, and have even been trained to respond to sounds from specific notes played in music.
Chimps are well known for being highly intelligent, getting into mischief, and sometimes forming groups. We’ve observed that they remember faces, recognize familiar people, and even empathize with others. With such a strong memory and cognitive capacity they probably don’t forget anything either, so perhaps they should be classified as supernatural beings.
Bonobos are a subspecies of chimpanzees that reside apart from the Congo River Basin. While they are believed to share 98% of the same DNA with chimps, bonobos have adapted to living alongside people and therefore differ in how they behave in society.
Humans obviously take the crown as the smartest life form on Earth. Not only do we have the biggest brains but we also lead unique lives as opposed to any other species across the planet. Humans not only enjoy leisure time but also get creative enough to invent things that help them cope with daily life.
Here is a quick overview of the IQ of the smartest primate species:
- Human: IQ 100
- Chimpanzee: IQ 80
- Bonobo: IQ 70
- Gorilla: IQ 60
- Orangutan: IQ 50
- Rhesus monkey: IQ 40
- Cynomolgus monkey: IQ 30
- Marmoset: IQ 20
- Macaque: IQ 10
- Pig-tailed macaque: IQ 5
How Much Brains Do Dolphins Have?
Dolphins are another group of intelligent marine mammals. They have been known to live for over 60 years, and their brains are quite large compared to other marine life. A dolphin’s brain is about 0.7 pounds (0.33 kg) in weight.
What About Birds And Reptiles?
Birds and reptiles are the next two groups of animals on the list. Both of these groups have much smaller brains than mammals or primates. However, birds still have significantly larger brains than reptiles. For example, a chicken has a brain that weighs just 0.2 ounces (6 grams). That is less than half of what a lizard brain weighs.
Which Mammals Have The Smallest Brains?
Mammals come last on the list when it comes to brain size. We are followed by bats, rodents, and lagomorphs. Bats have the smallest brains out of all mammals, weighing between 0.05 and 0.15 ounces (1.5 and 4 grams). Rodents have brains that range from 0.3 to 0.9 ounces (10 to 25 g). Lagomorphs have brains that weigh between 0.2 and 0.55 ounces (6 and 16 g).
How Many Brains Does An Octopus Have?
Octopi are invertebrates that belong to the phylum Chordata. They are related to vertebrates like sharks, frogs, and lizards. Like other chordates, octopi have eight arms, a tail, and a head. Unlike vertebrates, however, they don’t have bones. Instead, they have soft tissue called chitin.
Octopuses have four hearts, two lungs, and two kidneys. They also have two sets of eyes. Each eye contains three lenses, while each lens consists of five layers. There are also two types of neurons in their nervous system.
How Many Branches Does A Human Brain Have?
The human brain is made up of billions of cells. Each cell is connected to hundreds of others through tiny threads called dendrites. Dendrites receive signals from other cells and pass them along to the cell body. The cell body then sends the signal back to other cells. This process continues until the message reaches the nerve endings.
At this point, the signal travels down the axon to the synapse where it can be sent to the next neuron.
The number of branches in your brain depends on how you were born. If you were born prematurely, your brain will not have as many branches as if you were born at full term. In fact, premature babies’ brains may only have one branch per neuron.