Tiny sapient species are a staple of both sci-fi and fantasy, with both faeries and who-like races that live on dust specks found across the pages of various books. We've even had some excellent questions about them, like this one about armed sparrows. In reality, however, it seems as though there should be limits in terms of size that set a lower boundary on how big something can be and still be sapient. Below this size, a species would simply not have enough neurons to be able to form a brain that is capable of abstract manipulation of concepts. What would this size be, and what factors, such as chemical composition or structure of a life form, might influence it?

By a sapient species, I specifically mean a species capable of the types of thought that would allow for the development of things like advanced technology. The species need not necessarily have a human-like experience of reality.

  • $\begingroup$ I'm not certain we can give an exact answer here. We know how our neurons work (kind of), but that doesn't mean it's the only source of sentience. If, for example, we can make sentient AI it's 'brains' would fit on a micro computer the size of a chip potentially. Did you want to limit the question to standard human-like brain and evolution? $\endgroup$
    – dsollen
    Apr 8, 2015 at 15:42
  • 2
    $\begingroup$ Possible dupe of: What is the Smallest Sentient Species Possible? and Minimum Brain Size for Consciousness? $\endgroup$
    – Jax
    Apr 8, 2015 at 15:45
  • $\begingroup$ Also, I assume you are actually asking about sapient beings, not sentient? Sentient means aware, and most animals are. Sapience means actual human-like intellect and ability to think and reason. Is it safe to assume you actually are interested in the later, or are you interested in mere sentient? $\endgroup$
    – dsollen
    Apr 8, 2015 at 15:45
  • $\begingroup$ This appears to be a duplicate of this, which is marked a duplicate of this. $\endgroup$
    – Frostfyre
    Apr 8, 2015 at 15:47
  • $\begingroup$ @DustinJackson Yay for delays. $\endgroup$
    – Frostfyre
    Apr 8, 2015 at 15:48


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