By nature, Pokémon are incredibly complicated and fascinating creatures. In a sense, they are powerful and mystical monsters; beings that, scientifically speaking, may well surpass every other living creature, even humans. This is due to a critical and often-overlooked aspect of their being: their intelligence.
In nature, some level of intelligence is a necessity for every living organism. Some creatures are more intelligent than others; for example, a dog supports more substantial thinking power than an amoeba. A dog is a common choice for an intelligent animal, but an insect or a plant? Who would define these organisms as intelligent? Well as far as Pokémon go being complicated individuals, there are some Bug and Grass types (Grass types mainly being plants) who are smarter than man’s best friend. The intellect of Pokémon is one of the pivotal traits that truly makes them fantastic monsters.
I already stated that even Bug types are a very intelligent group. Don't believe me? Let’s use everyone’s favorite caterpillar, Caterpie, as an example. The real world creature that Caterpie is based off of is a Spicebush Swallowtail Caterpillar. If we were to more closely examine this particular caterpillar to try and deduce the pinnacle of it’s brain power, we would find out that essentially, even by bug standards, there is not a whole lot going on in this critter’s head. This caterpillar has no self-awareness, which means the Spicebush Swallowtail has no understanding that its existence is separate from the surrounding world. That is a trait common in creatures with small, undeveloped brains.
The Swallowtail Caterpillar can never understand human speech. Try having a conversation with one, you’ll see what I mean. Falling hand-in-hand with the lack of understanding speech, this critter obviously cannot learn commands. Also, since this caterpillar is a very simple organism, it cannot portray or recognize even simple emotion.
So, even though the Spicebush Swallowtail Caterpillar is the real-world counterpart for our buddy Caterpie, it obviously is outmatched in the intelligence category. What does Caterpie have to bring to the table? Let’s check out Caterpie’s intelligence in comparison to the real-world caterpillar.
Caterpie appears to be one of the most simple species of Pokémon, but nonetheless has very advanced intelligence. Being a “monster,” it is understood, but still scientifically amazing, that an invertebrate bug can support the brainpower of a Caterpie. For starters, Caterpie has a strong enough intellect to support self-awareness, which for a bug or insect, is very rare. The ability to be trained by a human fully shows that this Pokémon can understand, recognize, and acknowledge human speech, or at least can differentiate between the tones in a human’s voice (different vocal tones for emotion, such as anger, happiness, etc).
For a bug of any kind to understand human speech is incredible. For that bug to learn commands and obey a trainer shows intelligence on the level of a dog or a similar mammal. Learning commands and being able to remember them clearly shows that this Pokémon has a brain that is capable of both storing information and retrieving and recalling said information at the use of a command. In addition, by understanding speech and vocal tones, we see that that Caterpie can at a minimum understand emotion.
It is evident that Pokémon as a group far surpass normal animals in means of brain capacity and intelligence. Caterpie is an example of a Bug Pokémon; other types, such as Ghost or Psychic, have species with an intellect that may outstrip human intelligence. In addition, they have abilities that make this intelligence even more impressive. Some can read minds and also harness energy in objects and manipulate them with telekinesis or psychokenesis. While there is certainly variation among the species of the Pokémon world, the fact remains that that they are extraordinary monsters that are incredibly smart. They are able to communicate and form bonds with humans and they are able to portray emotion and adapt to changes in environment. It's no wonder they are so sought-after.
Oh, as for plants with brain power? That’s a whole other story.