How Do You Define "Intelligent Life"?

Update: The Xploration Outer Space show that features this topic is available for free online on Hulu here.

Last week we wrapped up a shoot for Xploration Outer Space in the San Francisco area for our Season 1 episode, “Life Beyond Earth."  For this episode, we tapped into the greatest alien-seeking minds at the Search for Extraterrestrial Intelligence (SETI).

One of the really interesting questions that came up during this shoot was "How do you define intelligent life." It was a fascinating question that stuck with me after filming. This post combines some of the interesting ideas I gathered at SETI as well as other information I found from other researchers in this field.

What is “intelligent” life?

In our show about “Life Beyond Earth” we will be making the distinction between microbial life and intelligent life as best we can.  This is an important distinction because when scientists find “life” on another planet, the public is going to want to know what it looks like - and if we can be friends with them. Spoiler alert: it’s probably not going to be little green women. Or anything that looks even close to us.  We are definitely the only humans in the universe, due to the process of evolution and such. But if they aren't little green women, then what will aliens look like? 

First of all, it’s more than likely that when we find life, we won't even be able to see it with our eyes. As Neil deGrasse Tyson points out in his book, Space Chronicles, there have been over ten billion species that have roamed the Earth, and only one as “intelligent” as humans.  So if we use that as a prediction for intelligent life in the universe, we have about a one in ten Billion chance of finding intelligent life.  So we can (should?) assume that intelligent life is pretty rare.

But what is “intelligent life” anyway?

Well, as it turns out, defining intelligence is a hard thing to do.  We even have a difficult time objectively defining intelligence within our own species (Oh hey there, imperfect standardized tests!).  So how can we begin to define what "intelligence" means for all living things? If we were to rank plants, insects, fish, reptiles, mammals, etc based on intelligence - what metric would we use to rank them? Who would win the Most Intelligent Being on Earth award?

Some have said that “intelligence” is the ability to develop and improve technology while integrating it within your own society.  That someone was definitely a human, because by that definition humans are the obvious winners.  But are there other ways we could define intelligence?

Laurance Doyle! One of the most intelligent, fascinating people I've ever been lucky enough to speak with!

Laurance Doyle! One of the most intelligent, fascinating people I've ever been lucky enough to speak with!

I spoke with Laurance Doyle, an astronomer at SETI, who offered other ways to think about intelligent beings.  He said that if we define intelligence by sustainability (meaning, the ability to survive over a long period of time) the most intelligent being might be trees, or plants in general.  Trees create their own food, reproduce fairly efficiently by just spewing their seeds everywhere, and many of them can live in extreme environments. Land plants have survived on Earth longer than any insect, amphibian, reptile, mammal or bird. So are plants the most intelligent “being” on Earth?

Laurance also said that if we define intelligence by complexity of communication, then whales and dolphins could be front runners over humans.  There are certain ways that scientists analyze language structure complexity that could be applied to whale/dolphin “languages.” It mostly has to do with something called “Information Theory” and the quantification of information. By this method, whales and dolphins have a communication structure that is just as complex, and some would say more complex than humans. But, there are other scientists who disagree entirely.  If you want to dive into this pretty fascinating area, this article is a good place to start.

So who wins the Most Intelligent Being on Earth award? Trees? Whales? Dolphins? Humans? What do you think?  

I’m still going to go with humans. I definitely don’t want to be in the camp that is like “But….trees!!!” This is probably just my egocentric human brain talking, but I’m going to say humans are obviously the winner since we have a space program. Call me when dolphins send themselves to Mars. 


Name *