Are Human Beings Rational Animals?

Are Human Beings Rational Animals?

Last update: 15 April, 2018

We’re going to split up this reflection into two parts so it’s easier to understand. In the first part we’re going to try to shed light on what it means to be an animal. And in the second part we’ll talk about our rationality and how we use it.

Human beings are just animals

According to biological studies, human beings belong to the animal kingdom. That’s because we meet the basic characteristics and functions of an animal (for more info, read this link). But of course you could also say that as humans we have a lot more intelligence and reason. And you might use that specific detail to set us apart from animals.

Are human beings rational beings or animals?

But intelligence is just another adaptation to our environment. It’s necessary for the survival of our species. In the same way that cats and dogs survive because they have claws and teeth, human beings have intelligence as just another resource to help us survive. In fact, if we didn’t have this cognitive capacity and flexibility we probably would have already gone extinct (we’re not the most agile or the biggest).

There are also experts who say that we’re the most well-adapted species. But the truth is that when it comes to adaptation and natural selection, the words “more” and “less” don’t make much sense. A well-adapted species is one that’s not in any danger of going extinct. That means that all, or almost all of the species that aren’t extinct right now are well-adapted. 

Another thing is that our flexibility is what allows us live in very different parts of the earth in all kinds of conditions. But we’re not alone in that. There are plenty of bacteria that are much better than us at this. When you think of it in these terms we’re just another animal, with our own specific characteristics, but no better or worse than any other living being.

The rational animal

A second thing to think about, if we go back to the title of the article, is another question: what does the rational part of “rational animal” mean? Normally we see rationality as the ability to evaluate problems or events in an objective way and respond to them logically. But you can also see it as the antonym of words like emotional or instinctive.

Separating emotional from rational doesn’t make sense. And that’s because our behavior is always influenced by both parts. Most of the time it’s impossible to separate one of those influences from the other. 

It is true that sometimes the emotional side plays a bigger part, and that other times we’re rational. But you still can’t see the two things as two independent ways of behaving. They both have a constant influence on each other.

But let’s put emotion aside for a second. Instead let’s talk about how whether our neocortex is totally “rational.” The psychology of thinking made a comparison of human logic and term logic. The second kind of logic is the purest and most mathematical kind. It didn’t take researchers long to realize that these two ways of thinking don’t line up.

How do humans reason?

So if human beings don’t use logic when we think, how exactly do we reason? If you want to find an answer, you have to think about how human beings only have a certain amount of cognitive resources, and a lot of the time we have to act fast. 

If we could be “purely logical,” we’d use a lot of resources making decisions and we’d be able to respond in a more complex way. But that’s not really how it is, is it?

We  reason by using mental shortcuts, which are known in psychology as heuristicsThis is reasoning that uses probability and bases itself on experiences, whether they’re direct or indirect.

On an adaptive level it’s more effective to reason based on probabilities, which means you’re taking a controlled risk that you’re wrong, than it is to run no risk and take forever to make decisions.

Making decisions as rational animals.

Are human beings rational animals?

Now that you’ve seen some of the facts about human thoughts and behavior, there are a few things to reflect on. Be very careful with the statement “human beings are rational animals.” Rational or not, we shouldn’t say it makes us better or worse at adaptation than other living beings.

Besides, the studies all say that we’re never completely rational. In fact we aren’t rational for most of our important decisions. Instead, we actually act based on what intuition or our heart (primitive instinct) tells us to do.

One thing we can call ourselves, as social psychology puts it, is “cognitively impaired.” There’s a reason for that label: our brains are programmed to use as little of our resources as possible. They might make more effort with a bigger problem, but they’ll always try to save energy.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.


  • Cosmides, L. (1989). The logic of social exchange: Has natural selection shaped how humans reason? Studies with Wason Selection Task. Cognition, 31, 187‐276.
  • Cosmides, L. and Tooby, J. (1992). Cognitive adaptations for social exchange. In Barkow, Cosmides and Tooby (1992), 163‐228.
  • Macintyre, Alasdair (2001) Animales racionales y dependientes: por qué los seres humanos necesitamos virtudes. Paidós
  • Bernal, Anastasio (2015) Psicología social: Algunas claves para entender la conducta humana. Biblioteca Nueva

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.