<blockquote>
  <p>If non-human animals do have intelligence too, why is their intelligence not as advanced as humans?</p>
</blockquote>

<p>Notions like “advanced” or “better” really have no place in evolutionary thinking. Again, evolutionary fitness is about self-reproduction and success compared to whatever competition is present at any moment. There is no force “optimizing” species to meet some external criteria of “progress”.</p>

<p>One important observation is that (relatively) simple species have in fact been quite successful (in terms of number of individuals, total biomass, capacity to survive climate changes and other disruptive events, etc.). Humans have been flourishing very recently (few thousands of years), colonizing big parts of the earth, reaching large population numbers but before that there is evidence that they went through a severe population bottleneck as recently as 70000 years ago. Great apes populations are also not very large and all species are considered endangered. </p>

<p>Sustaining a large brain and human intelligence is in fact extremely onerous. The human brain requires a lot of energy. Furthermore, it has become too big to go through the mother's womb so that it still undergoes growth after birth, meaning that human babies require a lot of care and protection. All that suggest that “high intelligence” is not always such a big advantage, evolutionary speaking. As often, there are trade-offs and various successful “strategies”.</p>

<p>In any case, you might be interested in <a href="http://en.wikipedia.org/wiki/Evolution_of_human_intelligence">Wikipedia's article on the “Evolution of human intelligence”</a>.</p>

CC BY-SA 3.0
2013-09-05T22:36:33.423Z
I signed up just to have the pleasure of up voting your answer. I
think the bottleneck was for Cro-magnon in eastern south of Africa,
while Neandertal came to Europe 200.000 years ago. But we are supposed
to be much more Cro-magnons than Neandertals. My own belief regarding
intelligence and empathy is that it emerged because modeling the world
and other beings helped both predators and preys ... at high
processing cost. It is however surprising that diminishing returns did
not stop intelligence growth. Almost did.
babou
CC BY-SA 3.0
2013-07-31T06:01:57.710Z
2013-07-31T09:30:31.320Z
2013-07-31T09:30:31.320Z
Gala
<p>Let's first be clear that we didn't evolve from monkeys/apes/etc.  That's a common misconception.  Evolution states that we and monkeys/apes/etc. evolved from a common ancestor.  Same with fish.  If you go back far enough, we and fish share a common ancestor... we did not, however, evolve from today's Salmon or Macaque.</p>

<p>That being said, the origin of intelligence is an elusive topic.  Intelligence isn't the most tangible concept to study in an evolutionary context as the associated molecular evidence is highly circumstantial.  For example, it's difficult to interpret what behavioral differences emerged from the differences in receptor distribution and types associated with our genetic fission from the common ancestor.  </p>

<p>Now that we've said that, there's several theories; many of them stem from language.  It is thought that the articulation allowed by language allows us to more carefully think about things... but there's always the possibility that the reasoning came first and facilitated the language.</p>

<p>One of the more interesting theories I've read is <a href="http://en.wikipedia.org/wiki/Bicameralism_%28psychology%29" rel="nofollow">the bicameral mind</a>.  Of course, note the criticisms against it:</p>

<p>"It is one of those books that is either complete rubbish or a work of consummate genius, nothing in between! Probably the former, but I'm hedging my bets."
-Richard Dawkins</p>

<p>Others argue that <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&amp;aid=30921" rel="nofollow">human consciousness is a social construct</a>.</p>

CC BY-SA 3.0
2013-07-31T05:23:15.720Z
Good point in the first paragraph but I don't think the evolution of intelligence has much to do with evolutionary psychology. One of its main assumption/tenet/characteristic is that *specific* behaviors or psychological traits evolved. That's the main point of contention and the level evolutionary psychologists discuss; they don't have much use or much to say about some general information processing capacity. Furthermore, evolutionary thinking about cognition is certainly not limited to evolutionary psychology, there is no reason to consider it “belongs” to its proponents in any way.
Gala
CC BY-SA 3.0
2013-07-31T12:37:30.937Z
the question has been changed since I answered it, from human reasoning (a process with an associated verb: to reason) to human intelligence (a much broader concept).   I don't equate "general information processing" to either human intelligence or human reasoning.  Even inanimate objects can process information.
Keegan Keplinger
CC BY-SA 3.0
2013-07-31T12:42:01.580Z
Also, I don't think insects "reason".  They certainly process information... whether they're intelligent or not depends on how you define intelligence (different researchers will define it different ways, but there's a lot of room for anthropomorphizing there.)
Keegan Keplinger
CC BY-SA 3.0
2013-07-31T13:24:22.103Z
I see your point but it is only tangentially related to the one I was trying to make, I still don't think any of this has much to do with evolutionary psychology.
Gala
CC BY-SA 3.0
2013-07-31T13:29:58.643Z
I think that's a debate in itself, but since it's not a primary point, I will just remove it to avoid the distraction.
Keegan Keplinger
CC BY-SA 3.0
2013-07-31T00:24:25.513Z
2013-07-31T13:33:35.760Z
2013-07-31T13:33:35.760Z
Keegan Keplinger
<p>Your own theory is bad because it seems to follow from a Lamarkian interpretation of evolutionary theory. In Lamarck's idea, a crab's offspring will have the genes bigger claws if the crab exercises his own claws a lot before giving birth. In the same way, you're suggesting that the way ancient human diets improve their mental health somehow led to this mental health being passed down to us.</p>

<p>To better understand the question, you should think not about what habits ontogentically lead to better thinking, but about what problems that ancient humans uniquely faced such that ultimately only those with our intelligence were able to successfully mate and reproduce.</p>

CC BY-SA 3.0
2013-08-04T08:53:51.587Z
+1 Good points even if I am not sure if the problem in the OP's thinking is specifically related to the inheritance of acquired characteristics. As an aside, it's true that this view has been associated with Lamarck's name but in fact his ideas were much broader than that and this particular mistake was also committed by Darwin (e.g. in *The Expression of the Emotions in Man and Animals*). Besides neither of them had any notion of “gene”, for obvious reasons.
Gala
CC BY-SA 3.0
2013-08-16T18:35:49.717Z
Good answer. But why does certain humans (those ones that later did reproduce and successfully mate) actually developed intelligence or cognitive thinking? That's my main question and the whole debate about
Eric Frick
CC BY-SA 3.0
2013-08-04T02:58:03.950Z
2013-08-04T02:58:03.950Z
Psyche
<p>I have been debating the following topic with a friend.</p>

<ul>
<li>She argues that humans do not descend from chimpanzees or orang-utans, because if we did, such animals would share the same cognitive thinking that humans have.</li>
<li>I argue that we do descend from that such animals, and that a high protein diet has allowed early humans to develop a better memory, intelligence, and other mental processes.</li>
</ul>

<h3>Questions</h3>

<ul>
<li>What is the  the real origin of human intelligence? </li>
<li>If non-human animals do have intelligence too, why is their intelligence not as advanced as humans?</li>
</ul>

CC BY-SA 3.0
2013-07-30T17:39:47.787Z
This question appears to be off-topic because it is much more about how evolution works than cognitive science.  Perhaps the biology SE would be a better venue?
Krysta
CC BY-SA 3.0
2013-07-30T17:43:33.650Z
probably. Thanks for the advice
Eric Frick
CC BY-SA 3.0
2013-07-30T18:06:43.163Z
I have heard some explanations revolving around the standing position and opposing thumb, leading to the gripping hand, tool use and ultimately higher cognitive functions. No matter the merits of this theory, ultimately, it does not seem directly relevant to establishing a link between primates. Following your friend's logic, why would any animal on earth not be a human? Why would chimpanzees or for that matter turtles, frogs or insects not benefit from increased memory or intelligence?
Gala
CC BY-SA 3.0
2013-07-30T18:09:07.613Z
Fact is the current state of any particular species is the result of various evolutionary processes (among them natural selection) and interaction between these processes and a changing environment (including other species). A species can strive as long as it is successfully occupying some niche and the most successful in that respect are not necessarily humans. Evolution is just not a process leading inexorably to a single outcome be it humans or high cognitive function.
Gala
CC BY-SA 3.0
2013-07-30T18:12:43.880Z
Besides, many great apes are actually endangered. Once they disappeared and only humans are left, you could look at the whole process and say that “all primates developed higher cognitive capacities”. That's the way evolution works: With more successful populations drifting away then displacing less successful ones over a long time, not by individual animals “morphing” into a more successful form instantly.
Gala
CC BY-SA 3.0
2013-07-30T18:15:57.317Z
@Krysta I would think the evolution of cognitive function to be completely on topic.
Gala
CC BY-SA 3.0
2013-07-30T18:27:44.093Z
Thanks for participating Gael. I agree with you in saying that evolution isn't always make the "latest" cognitive individual. Probably, if evolution is made "on demand"(according to the changing environment) what could happen to lead the human predecesor to develop a higher cognitive level? And, speaking properly, in which way better intelligence makes the better specie? (I mean, some humans are will to destroy other species and the human specie itself)
Eric Frick
CC BY-SA 3.0
2013-07-30T18:31:56.707Z
@GaëlLaurans I agree!  But it seems the confusion here is less about how cognitive function evolved, and more about how evolution works in general--since answering this question would involve discussing why all descendants of a given critter might not share all the same adaptations.
Krysta
CC BY-SA 3.0
2013-07-30T18:34:23.377Z
@Krysta let's say that we're speaking only from humans. What did generate the Reason? And why animals doesn't have it? (What I call reason is recognizing myself as a human)
Eric Frick
CC BY-SA 3.0
2013-07-30T19:09:45.587Z
@ErickFrick I haven't been very clear, there is really nothing happening “on demand” or anything “leading” one species or one animal to develop anything. You should really forget this sort of teleological thinking. There are only many variants being created all the time (through sexual reproduction, mutations, etc.) If some variants happen to be more successful (in the sense of fostering their own reproduction, whether they are “better” in any other sense is not relevant), they will tend to spread.
Gala
CC BY-SA 3.0
2013-07-30T19:11:07.180Z
Also, I didn't feel it necessary to point this out earlier but this isn't really an all or nothing proposition. Animals obviously have some information processing capacity, memory, intelligence, etc.
Gala
CC BY-SA 3.0
2013-07-30T19:11:42.607Z
@Krysta After reading the last comments, I think you are right!
Gala
CC BY-SA 3.0
2013-07-31T03:33:09.643Z
I've given the question a few edits to hopefully clarify the question.
Jeromy Anglim
<intelligence><consciousness><evolution><cognitive-neuroscience><animal-cognition>
How did the unique features of human intelligence evolve?
Eric Frick
# How did the unique features of human intelligence evolve?

(Asked by: username_0 on 2013-07-30)

I have been debating the following topic with a friend.

* She argues that humans do not descend from chimpanzees or orang-utans, because if we did, such animals would share the same cognitive thinking that humans have.
* I argue that we do descend from that such animals, and that a high protein diet has allowed early humans to develop a better memory, intelligence, and other mental processes.

### Questions

* What is the the real origin of human intelligence?
* If non-human animals do have intelligence too, why is their intelligence not as advanced as humans?

**Tags:** intelligence, consciousness, evolution, cognitive-neuroscience, animal-cognition

> **Comments:**
> **username_1**: This question appears to be off-topic because it is much more about how evolution works than cognitive science.  Perhaps the biology SE would be a better venue?  
> **username_0**: probably. Thanks for the advice  
> **username_2**: I have heard some explanations revolving around the standing position and opposing thumb, leading to the gripping hand, tool use and ultimately higher cognitive functions. No matter the merits of this theory, ultimately, it does not seem directly relevant to establishing a link between primates. Following your friend's logic, why would any animal on earth not be a human? Why would chimpanzees or for that matter turtles, frogs or insects not benefit from increased memory or intelligence?  
> **username_2**: Fact is the current state of any particular species is the result of various evolutionary processes (among them natural selection) and interaction between these processes and a changing environment (including other species). A species can strive as long as it is successfully occupying some niche and the most successful in that respect are not necessarily humans. Evolution is just not a process leading inexorably to a single outcome be it humans or high cognitive function.  
> **username_2**: Besides, many great apes are actually endangered. Once they disappeared and only humans are left, you could look at the whole process and say that “all primates developed higher cognitive capacities”. That's the way evolution works: With more successful populations drifting away then displacing less successful ones over a long time, not by individual animals “morphing” into a more successful form instantly.  
> **username_2**: @username_1 I would think the evolution of cognitive function to be completely on topic.  
> **username_0**: Thanks for participating Gael. I agree with you in saying that evolution isn't always make the "latest" cognitive individual. Probably, if evolution is made "on demand"(according to the changing environment) what could happen to lead the human predecesor to develop a higher cognitive level? And, speaking properly, in which way better intelligence makes the better specie? (I mean, some humans are will to destroy other species and the human specie itself)  
> **username_1**: @GaëlLaurans I agree!  But it seems the confusion here is less about how cognitive function evolved, and more about how evolution works in general--since answering this question would involve discussing why all descendants of a given critter might not share all the same adaptations.  
> **username_0**: @username_1 let's say that we're speaking only from humans. What did generate the Reason? And why animals doesn't have it? (What I call reason is recognizing myself as a human)  
> **username_2**: @ErickFrick I haven't been very clear, there is really nothing happening “on demand” or anything “leading” one species or one animal to develop anything. You should really forget this sort of teleological thinking. There are only many variants being created all the time (through sexual reproduction, mutations, etc.) If some variants happen to be more successful (in the sense of fostering their own reproduction, whether they are “better” in any other sense is not relevant), they will tend to spread.  
> **username_2**: Also, I didn't feel it necessary to point this out earlier but this isn't really an all or nothing proposition. Animals obviously have some information processing capacity, memory, intelligence, etc.  
> **username_2**: @username_1 After reading the last comments, I think you are right!  
> **username_3**: I've given the question a few edits to hopefully clarify the question.  

---

## 3 answers

### Answer by username_2 on 2013-07-31. Score: 6

> If non-human animals do have intelligence too, why is their intelligence not as advanced as humans?

Notions like “advanced” or “better” really have no place in evolutionary thinking. Again, evolutionary fitness is about self-reproduction and success compared to whatever competition is present at any moment. There is no force “optimizing” species to meet some external criteria of “progress”.

One important observation is that (relatively) simple species have in fact been quite successful (in terms of number of individuals, total biomass, capacity to survive climate changes and other disruptive events, etc.). Humans have been flourishing very recently (few thousands of years), colonizing big parts of the earth, reaching large population numbers but before that there is evidence that they went through a severe population bottleneck as recently as 70000 years ago. Great apes populations are also not very large and all species are considered endangered.

Sustaining a large brain and human intelligence is in fact extremely onerous. The human brain requires a lot of energy. Furthermore, it has become too big to go through the mother's womb so that it still undergoes growth after birth, meaning that human babies require a lot of care and protection. All that suggest that “high intelligence” is not always such a big advantage, evolutionary speaking. As often, there are trade-offs and various successful “strategies”.

In any case, you might be interested in [Wikipedia's article on the “Evolution of human intelligence”](http://en.wikipedia.org/wiki/Evolution_of_human_intelligence).

> **Comments:**
> **username_4**: I signed up just to have the pleasure of up voting your answer. I think the bottleneck was for Cro-magnon in eastern south of Africa, while Neandertal came to Europe 200.000 years ago. But we are supposed to be much more Cro-magnons than Neandertals. My own belief regarding intelligence and empathy is that it emerged because modeling the world and other beings helped both predators and preys ... at high processing cost. It is however surprising that diminishing returns did not stop intelligence growth. Almost did.  

---

### Answer by username_5 on 2013-07-31. Score: 5

Let's first be clear that we didn't evolve from monkeys/apes/etc. That's a common misconception. Evolution states that we and monkeys/apes/etc. evolved from a common ancestor. Same with fish. If you go back far enough, we and fish share a common ancestor... we did not, however, evolve from today's Salmon or Macaque.

That being said, the origin of intelligence is an elusive topic. Intelligence isn't the most tangible concept to study in an evolutionary context as the associated molecular evidence is highly circumstantial. For example, it's difficult to interpret what behavioral differences emerged from the differences in receptor distribution and types associated with our genetic fission from the common ancestor.

Now that we've said that, there's several theories; many of them stem from language. It is thought that the articulation allowed by language allows us to more carefully think about things... but there's always the possibility that the reasoning came first and facilitated the language.

One of the more interesting theories I've read is [the bicameral mind](http://en.wikipedia.org/wiki/Bicameralism_%28psychology%29). Of course, note the criticisms against it:

"It is one of those books that is either complete rubbish or a work of consummate genius, nothing in between! Probably the former, but I'm hedging my bets."
-Richard Dawkins

Others argue that [human consciousness is a social construct](http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=30921).

> **Comments:**
> **username_2**: Good point in the first paragraph but I don't think the evolution of intelligence has much to do with evolutionary psychology. One of its main assumption/tenet/characteristic is that *specific* behaviors or psychological traits evolved. That's the main point of contention and the level evolutionary psychologists discuss; they don't have much use or much to say about some general information processing capacity. Furthermore, evolutionary thinking about cognition is certainly not limited to evolutionary psychology, there is no reason to consider it “belongs” to its proponents in any way.  
> **username_5**: the question has been changed since I answered it, from human reasoning (a process with an associated verb: to reason) to human intelligence (a much broader concept).   I don't equate "general information processing" to either human intelligence or human reasoning.  Even inanimate objects can process information.  
> **username_5**: Also, I don't think insects "reason".  They certainly process information... whether they're intelligent or not depends on how you define intelligence (different researchers will define it different ways, but there's a lot of room for anthropomorphizing there.)  
> **username_2**: I see your point but it is only tangentially related to the one I was trying to make, I still don't think any of this has much to do with evolutionary psychology.  
> **username_5**: I think that's a debate in itself, but since it's not a primary point, I will just remove it to avoid the distraction.  

---

### Answer by username_6 on 2013-08-04. Score: 1

Your own theory is bad because it seems to follow from a Lamarkian interpretation of evolutionary theory. In Lamarck's idea, a crab's offspring will have the genes bigger claws if the crab exercises his own claws a lot before giving birth. In the same way, you're suggesting that the way ancient human diets improve their mental health somehow led to this mental health being passed down to us.

To better understand the question, you should think not about what habits ontogentically lead to better thinking, but about what problems that ancient humans uniquely faced such that ultimately only those with our intelligence were able to successfully mate and reproduce.

> **Comments:**
> **username_2**: +1 Good points even if I am not sure if the problem in the OP's thinking is specifically related to the inheritance of acquired characteristics. As an aside, it's true that this view has been associated with Lamarck's name but in fact his ideas were much broader than that and this particular mistake was also committed by Darwin (e.g. in *The Expression of the Emotions in Man and Animals*). Besides neither of them had any notion of “gene”, for obvious reasons.  
> **username_0**: Good answer. But why does certain humans (those ones that later did reproduce and successfully mate) actually developed intelligence or cognitive thinking? That's my main question and the whole debate about  

---

