Alien and fantasy creatures can be designed in an infinite number of ways. But are there physiological traits that would be common among all tool-developing (technology-building) species?

As an example, I suspect all such species must have some means of manipulating small things. Whether it be fingers and an opposable thumb or well coordinated tentacles or a remarkably manipulatable pair of jaw pincers. Physiologically, the species needs the ability to manipulate things implying fine motor control and gripping power.

I'm not as interested in how the traits are manifest as I am what the basic traits are. Is there a short list of such traits that can guide creature builders?

  • 1
    $\begingroup$ if by tool using you mean capable of creating and refining tools, then they need at least two manipulators of some kind and spatial reasoning skills at the bare minimum. Anything else is pure guess work. $\endgroup$
    – John
    Dec 29, 2017 at 6:00
  • 2
    $\begingroup$ Beyond the ability to manipulate things, all the other traits I can think of are mental processes, such as causal reasoning and narrative ability (chaining together cause-effect sequences to reach an objective), logic, imagination, memory and a certain amount of leisure time beyond basic pure survival needs. $\endgroup$
    – Lee Leon
    Dec 29, 2017 at 13:33
  • 1
    $\begingroup$ They need 3D spatial awareness and the sensory apparatus to use it. A hammer is worthless as a hammer if you can't accurately aim it at what you want to hit. $\endgroup$ Dec 29, 2017 at 16:51
  • $\begingroup$ To add to the answers: a not-yet tool building creature would need an incentive to build tools, i.e. a weakness that prevents it from accessing certain resources, like no long and thin appendages to be able to get to bugs living in narrow tunnels, a not strong enough jaw to crack nut shells, not enough strength/not sharp enough teeth/not quick enough locomotion to hunt down larger prey, etc. $\endgroup$ Jan 2, 2018 at 13:36
  • $\begingroup$ As we don't even have a proper definition of what it means to be tool-building (in the first place what counts as a tool, then what counts as crafting a tool as opposed to manipulating a found object, etc.), I'm not sure we can give a meaningful answer beyond personal assumptions and biases. $\endgroup$ Jan 2, 2018 at 20:18

3 Answers 3


I have been considering something similar recently as part of hobby speculation regarding Artificial Intelligence: what are the fundamental requirements for technical intelligence.
Because I've considered this lots, this may turn into an extremely long answer, but we'll see what happens eh?

First up, some quick notes:

  • I define technical intelligence as the ability to grow collective intelligence and create meta-tools. Many animals can learn tricks (eg a dog), but it will not pass them on to it's offspring. Many animals can use rocks and sticks, but only one other than humans creates them, and none other than humans create tools that create tools. That said, in the software development field we are often so busy making tools to make tools that we lose track of the end goal....

  • One main assumption is that a creature's body is shaped by evolution, and that it cannot change it significantly. I assume that their is a non-minor link between physical form and intelligence, and I assume that all current earthly creatures are near the maximum intelligence of their physical forms, or in some cases, meerely need more time to achieve technical intelligence.

  • One conclusion I have come to is that beyond a certain point, a species is able to create enough tools of enough fidelity to ignore any physical requirements it's physical form lacks. Humans can study nuclear physics even though we can't see neutrons. A creature with low manipulation skills may be able to make it up in other ways.
    That said, without the ability to perceive or manipulate a certain aspect of the environment will result in no development in that area. It may well be there is some physical phenomenon in the universe that we cannot perceive nor touch, and as a result we cannot investigate it.

  • Finally, here on Earth we have exactly one technical intelligence: Humans. This is not a sufficient amount of datapoints for any sort of scientific study or conclusion on what the exact requirements are. So this is more an exploration of why humans are the only technical intelligence on Earth.

Physical Requirements:

  1. They need the be able to percieve This should be fairly obvious. Without perception of the environment, a forming intelligence will go crazy or commit suicide. Imagine if you had no eyes, no ears, no sense of smell or touch. How long would you remain sane? An earthly lifeform that has no perception but is alive is called a plant. A few can perceive a bit (such as some flowers tracking the light, or the venus flytrap catching it's prey), but they can see too little of their environment to be able to develop an intelligence.
    The exact senses are unimportant, though it will influence their later development - a blind species may never notice the stars.
    Other things that may matter include the range of vision (eg depth perception of items at close distances), the spectrum, and the resolution.

  2. They need to be able to manipulate If you had no arms, no legs, and could not even blink, how long would you remain sane? Similar to the ability to perceive, the ability to manipulate is required for an intelligence to emerge. The manipulation method must have sufficient dexterity and strength. Dolphins, dogs and so on are all highly intelligent creatures, but they lack dexterity.
    They also require multiple manipulators. An elephant is again highly intelligent, but a single trunk does not provide the ability to hold a tool and work-piece at the same time.
    Additionally, the field in which it manipulates it must be able to percieve. Many birds are quite intelligent creatures, but cannot see what their otherwise dexterous feet are working on. Hence it is unlikely they will achieve advanced tool use.

Closely linked to both perception and manipulation is the environment. Living on a featureless white plane in the fog will send a human crazy. Living in a world that is nothing but random flashing lights will also drive him mad. To some extent evolution may compensate and the intelligence may adapt to it's environment, but I suspect many places can harbour life, but not tool-using-intelligent life.

  1. Able to survive. An intelligent creature needs to be able to learn, and to do so, it needs to not die the instant it is touched. Humans are pretty tough creatures. You can cut our limbs off and we don't die. Try that with some other animals and you'll find yourself with a carcass. A creature much frailer than it's environment will not be able to develop tool use as they will never be able to learn from mistakes.
    This is again closely linked to environment. A human is completely unable to survive underwater, and a fish unable to survive on land. Just because a species is not robust in a gravitation field, on earth, at standard temperatures and pressures, does not prevent it from achieving technical intelligence in some other environment.

Social Requirements

  1. Communication. Assuming that a creature can perceive and manipulate, it is probably able to communicate. But the better it can communicate, the faster knowledge can be transferred. If communication is too slow, then the next generation cannot build on the work of the previous. If every generation has to discover that it can hit a lion with a rock, without the ability to learn from it's parents, then that intelligence will be limited to primitive tool use. Even if you injected knowledge into a single generation, the very next generation it would be lost. All major technological advances have ridden on the back of an improvement in communication. The most significant advances were probably: parenting, taming animals for riding, writing, printing press, radio, television, internet. Each one enabled a larger, more stable culture.

  2. Empathy No-one likes a race of psychopaths. Without the ability to empathise with others of it's race, a culture can never form, and they can never support the scientists and thinkers required for higher learning. You'd end up being limited to individual intelligence again, just the same as if you had no communication. I'd say that humanity rides the border of too-little empathy. We have fought with each other ceaselessly for generations and generations, and lots centuries of man-years of work to our lack of empathy. Riding with this is the physical requirement of being able to express emotion. Pure communication may not be enough, as we perceive emotion primarily through body language and looking at each others faces. If our faces were not expressive, would we be able to form a culture? I'm not sure.

Mental Requirements

  1. Memory A creature must be able to learn, and part of this is remembering. It must be able to remember both short term and long term. The more accurate it's memory, the better. That said, human brains are pretty poor. We can't remember things even just moments after seeing/hearing them (at least, my face/name association sucks).

  2. Mental Speed. The Portia spider can actively plan a path to it's prey, it just takes a very long time to do so (on order of minutes). If an intelligence is too slow to "think" it will take a hugely long time to bootstrap as it will constantly be prey to other creatures.

  3. Mental Ability. This is a super-hard one to define, but one textbook (Artificial Cognition Architectures by James A. Crowder, John N. Carbone and Shelli A. Friess) lists things like reasoning and testing hypotheses as required for learning. However, I would list these as subsets of creativity and curiosity. Without those two traits we would not make anything new, nor seek to learn anything we did not already know.


You will need:

  • The ability to grasp an object
  • Enough mental capacity to understand cause and effect
  • Enough strength to be able to use crude tools, as those will be developed first
  • Fine motor skills to control the tools

These will get you simple tools, like using rocks and sticks to break things or scoop things out of hard-to-reach areas. To get more advanced tools, you will need:

  • Long term memory to remember what you originally planned to use this tool for
  • Very fine motor skills for crafting of the tools
  • Enough mental capacity for more advanced problem solving (being able to envision more than one step to reach a goal)
  • A rich environment that allows enough time in the day for creative thinking
  • A rich environment with enough resources to create the tools

Not strictly necessary, but advanced tools are not likely to be created without:

  • Already widespread use of crude tools
  • A social, cooperative society, ideally with some basic means of communication
  • An environment that highly rewards creation of tools (I'm thinking near water for fishing, or near large prey for hunting)
  • $\begingroup$ Actually, i'd oppose the idea of a rich environment being necessary - or at least a rich environment on its own. After all, most tool using comes from problem-solving, but having a very rich environment lowers the necessity for said tools. $\endgroup$
    – Hannah
    Jan 1, 2018 at 13:14
  • $\begingroup$ @Hannah that's why I added the bit about the environment that rewards tools. I would think that an environment with just enough resources to support a small amount of leisure time with the use crude tools, and also have much richer rewards for more advanced tools would be ideal $\endgroup$
    – bendl
    Jan 1, 2018 at 19:09
  • $\begingroup$ This is good. But what about dolphins? sciencemag.org/news/2011/07/why-dolphins-wear-sponges Do they have fine motor skills? $\endgroup$
    – Willk
    Jan 7, 2018 at 3:48
  • $\begingroup$ @Will I'd say that in the grand scheme of things they have fine enough motor skills. I should maybe fix my answer to reflect this, but they only need enough motor skills to use the level of tool you're talking about. Very simple tools will have very crude motor skills. But still better than a banana in the grand scheme of things ;) $\endgroup$
    – bendl
    Jan 7, 2018 at 4:20

Great general answers out there. I'll focus on one single specific issue.

Obviously, it holds for anthropomorphic species as we know no better examples.

Opposing thumbs

Opposing thumb is the requirement for grabbing and holding a tool securely. While one may imagine aliens with two opposing thumbs on each hand (someone did, but I forgot the book name), it is pretty much impossible to build a human-like civilisation with no thumbs.

If one can build a non-anthropomorphic civilisation is an open question. It's better to err on the good side and to think it's possible. The ways dolphins and ants handle things might help. Compare how crows and bonobos wield tools.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .