Hi, I'm Emily from the Brain Scoop taking over Earth Unplugged to show you around my home base here at The Field Museum in Chicago. As Chief Curiosity Correspondent, it is literally my job to be curious, which is pretty easy when you're surrounded by 25 million artifacts. From mosquitoes to dinosaurs to aardvarks and zebras, and things that have yet to be discovered. And that got me thinking about thinking. Is a bigger brain a better brain?

The record size for brains in the animal kingdom goes to the sperm whale, weighing in at 7.8 kg, or 17 pounds. That's five times heavier than my own grey matter. But sperm whales are big mammals, so having a big brain is a bit of a no brainer. In general, the larger the animal, the larger the skull, and so, larger the brain. It's no surprise then that the smallest mammalian brain belongs to the smallest known mammal, the Etruscan shrew. At only 16 mg, it's 130,000 times smaller than the brain of a sperm whale.

So does a bigger brain mean more intelligence? Because of the bigger body bigger brain problem, a more complex unit of measurement called the encephalization quotient, or EQ, is sometimes used. This is the ratio of the animal's brain to body size relative to other similarly sized animals.

Humans win this scale of intelligence, hands down. You wouldn't expect an animal of our size to have a brain representing about 0.3% of their overall body weight. Our brain is 2%. Even compared to our close living relative like Lucy here, we have an exceptionally large brain.

It's in our name. Homo sapiens translates into 'wise man'. So if my brain was bigger than yours, would I be more intelligent than you? Brain size may account for about a 6.7% difference in intelligence. But, at only 1230 grams, Albert Einstein's brain was actually smaller than the average adult male's, weighing in at about 1400 grams. 

Activity levels in the lateral prefrontal cortex, a region just behind the temple, and the strength of neural pathways between this and the rest of the brain are thought to be major factors in determining intelligence. What about elsewhere in the animal kingdom? While an ant might only have a brain the size of a pinhead- put millions of them together and they have a collective intelligence. 

Take army ants for example. If you put hundreds of them on a flat surface, they'll walk around in ever decreasing circles until they eventually die of exhaustion. This may seem stupid, but these individual ants follow a simple set of rules that allow them to work in a million part colony. It enables them to work as a super organism, which allows them to carry out raids and keep nest temperatures constant to within a degree.

So, each ant acts a bit like a neuron within a huge shared brain. Now that's super smart. 

Octopuses are maybe the most intelligent invertebrates. Some of them have even figured out tool use with one species carrying around coconut shells to hide in. They're totally cheating though. They've effectively got 9 brains. One central one and then large ganglia at the base of each arm, containing 500 million neurons. That's roughly the same amount as a dog. 

What about prehistoric brains? Dinosaurs are thought to be about as intelligent as modern day reptiles. Herbivorous dinosaurs often had smaller brains. Despite being the size of a bus, the brain of a stegosaurus was the size of a lime. 

The most intelligent dinosaurs may have been theropods, close relatives of our modern day birds. They were thought to have large brains and superb eyesight in order to catch their speedy prey.

My friend Sue here is in the same group. She recently had her skull scanned, which revealed that she had enormous olfactory bulbs- the part of her brain responsible for smell. Each the size of a grapefruit, they were four times larger than her actual brain. 

Which begs the question- which part of your brain matters most for intelligence? You could argue that Sue has excellent nasal intelligence. I bet her decision making when it came to suppertime would have come super easy. 

And when it comes to social intelligence, dolphins and whales have a far larger and more elaborate limbic system than most creatures, including even us. This is part of the emotion-processing area of the brain, suggesting that their feelings and relationships might be more sophisticated and complex than we can ever begin to comprehend. 

So even though we've got a lot to be grateful for, with our impressively large brains and their 86 billion neurons, there's still a lot we don't know about ours and how other animals use theirs. One thing we know for sure is that there's still a lot more to learn.

So, if you want to keep those neurons firing, make sure to subscribe to Earth Unplugged for more amazing science about the natural world. And make sure to come find me over at The Brain Scoop in order to discover more exciting things to be curious about, here at The Field Museum.