This week’s lecture was very interesting because we talked about the evolution of human intelligence. One theory was that the hand or probably more specifically the thumb is what propelled human intelligence. The thumb may have allowed us to grasp things, which allowed us to manipulate the environment rather than submis to it. However, I think that the mind would have to come before the thumb because we would need the desire to manipulate the environment before we start selecting certain mates with that mutation (thumb). There was also talk about language separating humans from other species. I agree with this to some extent. We are, as far as we know, the only species that can use what Noam Chomsky calls transformational grammar, which is the ability to explain the deep structures of a sentence in many different ways. There has been a lot of research done on primates regarding language that is very shocking. One study is with a gorilla that has learned American Sign Language (over 1,000 words and she also understands over 2,000 spoken words). This gorilla can express past events and also make novel statements, which we thought only humans could do. Animals, and especially primates, have a very sophisticated language that we may not be able to understand and simply and arrogantly say they don’t possess. Their language may not be as “productive” as the human language but the word productive is very subjective. Studies also show that primates learn by emulation rather than imitation. Humans tend to imitate while learning but primates tend to go after results rather than specific behaviors. This is because of our highly social environments.
One pretty interesting but not very empirically based theory on human evolution is Terrance McKenna’s “Stoned Ape Theory”. His theory goes something like this: Primates lived in trees in Africa until it started drying up and they had to move done to the prairie lands. Living in the prairie lands required more attention because of predators and an adaptation in the foods they ate. When primates were foraging for food on the ground they stumbled upon mushrooms that gathered around herbivore dung, specifically the Psilocybin mushroom, which is psychoactive. These mushrooms were desirable because they increased sociability and eased communal tensions as well as increased awareness to the spatial environment. So he thinks that the mushroom is what inevitably increased intelligence. This is a pretty loose theory but still entertaining to think about. Also in high doses of psilocybin spontaneous vocalizations occur which McKenna believes to be the foundation of language.
Primatologists have found positive correlations between the neocortex size and group size of all primates. So if a certain species has larger social groups they tend to have a larger neocortex: showing a positive correlation. This is not true for all species though because the wasp lives in large numbers but has a small brain. One argument that I have is that maybe it isn’t the brain size that is increasing our intelligence. Our brain size hasn’t increased that dramatically over the past 1,000 years but I feel that our intelligence as a species has grown. So maybe intelligence grows separate of the brain. Maybe intelligence has more to do with cultural transmission. Or maybe our teaching practices and technologies have increased the ability to learn. Maybe humans haven’t become smarter but technology or cultural practices have allowed our ape-minded intelligence to surface.
Another issue with intelligence is that a lot of times we think of intelligence as productive. We think of intelligence in only ways that we see human intelligence evolving i.e. technology, science, and innovation. Intelligence can also be emotional and spiritual rather than physical. We think because we can explain nature so well that we are intelligent but at the same time what is it doing to human nature. I think as intelligence grows so doe’s mental illness and stress. You don’t see to many aborigines suffering from narcissistic personality disorder or whatever other disorders smart psychologists come up with. People who are intelligent often have issues with depression and drugs, stress and anxiety. So we have to look at the value of intelligence. I’m not saying intelligence is bad but trying to say that maybe its not the only type of intelligence. Other species or even cultures have different types of intelligence.
Terrance McKenna’s Stoned Ape Theory about 10 minutes long
timamoroso 
Your idea about the thumbs roll in evolution is interesting. I have to point out thought that thumbs evolved as a tool form arboreal locomotion (tree climbing), grasping branches to be specific. That’s whey are older ancestors and closest relatives have opposable thumbs on their feet. I wouldn’t think that an animal would necessarily to try tree climbing.
Its interesting when you bring in wasps as an example of social animals with small brains. I would point out that hive insects probably interact socially on an immensely different level than we do. I don’t know about wasps but I know that bees have a queen which is essentially everyone’s mother.
I think that any anthropologist (me being a student of anthropology) would tell you that your right to see a connection between intelligence and culture. Culture is the tool that has allowed us to survive and adapt to new living conditions over and over again.
Your comment about mental illness makes me think you might be interested to read this (link bellow). Its not directly related to what you were saying but I think its a good read for anyone who thinks critically of the phenomena of mental illness.
Hope my comments are of interest cheers!
Ian,
Thanks for the comment I’m glad you took the time to read my ideas and make a response. Its reassuring to know that people are still willing to engage in interesting dialogue these days!
It is interesting how much arboreal living has impacted our physiological and psychological evolution. It makes you think of how the mind and body are connected (something western medicine ignores). Arboreal life caused humans to develop, as you mentioned the thumb, stereoscopic vision (binocular and depth perception) and trichromatic vision color vision. It is believed that we developed color vision for the purpose of eating more ripe fruits, which can be distinguished by the color of its skin. Eating ripe fruit saves energy, which is evolutionarily advantageous.
All the ideas that I presented were not mine but arguments that I attempted to dissect. Your comment provoked me to dissect them further however. The argument was: did the thumb increase brain size or did the brain select the thumb? It’s kind of like the question, which came first: the chicken or the egg? The correct answer I assume is: both and simultaneously. These things happened over hundreds of thousands of years.
Something that didn’t happen over thousands of years (which I just learned the other day in my primate psychology class) was the language gene. I guess the FOXp2 gene is responsible for language development and motor function in the tongue and jaw. It is theorized that one person had this mutation (which all evolution feeds off of) and the selection of that mutation was tremendous. All Homo erectus whether they were aware of it or not were selecting mates with the FOXp2 gene because it allowed more sophisticated vocalizations.
Another mutation that allowed us to develop language and intelligence was smaller jaw bones (the pressure was probably fruit eating rather than meat because fruit is softer than meat). Weaker jawbones allowed for bigger brains because it had less muscle pulling down on the sides of the brain. If you think of clenching your jaw your muscle attach to your skull cause constriction. If we had huge muscles (meat and bone braking muscles) this would add excess pressure one the brain reducing brain size.
Anyways those are some things I know about the evolution of human intelligence. Thank you for responding. Do you have a website that I can check out? It would be great to keep the dialogue going!
Tim
Oh and I’ll check out the articles you posted!