Tuesday, November 19, 2013

Why was Rome so successful?

I particularly enjoy questions about our past that lead to an understanding of how we arrived where we are today.  By understanding how Rome came to dominant the Mediterranean world, we understand a crucial step in the formation of Western culture, giving us a greater understanding of why things turned out the way they did. Countless aspects of European culture were learned from the Romans. Before the Roman Empire, much of Europe was populated by barbarian tribes such as the Celts, illiterate and often nomadic. By 400 AD the Romans had civilized much of Southern and Western Europe, introducing Roman government, alphabet, numerals, language, architecture, philosophy, law, roads, agricultural techniques, and ultimately Christianity. Later governments, particularly the US, would adopt many Roman ideas in their constitution. The world today would look drastically different had a small village on the River Tiber named Rome not grown to dominate the Mediterranean world.

Rome began around 750 BC as a collection of rural villages along the River Tiber. The local geography provided a number advantages: the Tiber provided navigable access to the Mediterranean, nearby salt flats were a source of wealth, the surroundings had excellent soil that until ~1000BC had been fertilized by numerous active volcanoes in the area, and the city was located on five hills, making it easier to defend.

I believe Rome also benefited from its relative open-mindedness in terms of other cultures and ideas. For example, Rome frequently found itself in need of a larger labor force, and throughout most of its history foreigners were offered citizenship if they moved to Rome. Earlier in its history, it was also not uncommon for foreigners to gain power, for instance around 600 BC Tarquin, son of Greek royalty, became king (Rome had 3 political phases: Kingdom (750-509BC), Republic (509-49BC), and Empire (49BC-476AD), and is said to have brought Greek influence to Rome. And, learning from the example of Alexander the Great, once a town surrendered to Roman forces, local nobility frequently retained positions of power in the town. In addition, captured peoples were welcomed as citizens of Rome and foreign religions were tolerated, as long as proper deference was paid to the Roman pantheon. With such tolerance, captured peoples were less likely to revolt, and Rome, open to new ideas, learned immensely from its neighbors, especially the Greeks.

Romans were at times enamored with Greek culture, and Roman culture was in many ways shaped by Greek culture. Cicero writes "It was indeed no little rivulet that flowed from Greece into our city, but a mightly river of culture and learning." Roman legend claims that Rome was founded by the twins Romulus and Remus, later claimed to be descendants of Aeneas, a Trojan prince who escaped Troy with a small group of settlers at the time Troy fell to the Greeks (perhaps around 1200 BC). While this is surely myth, it reflects Rome's great debt to Greek culture. In the beginning of its history, Rome was flanked by the Greek-influenced Etruscans to the north, and Greek colonies throughout Southern Italy and Sicily. Many of the areas that became part of the Roman empire had previously been part of Alexander's empire and had been heavily influenced by Greek thought. Later in its history, many Romans learned Greek or would even study abroad in Athens. Many of the ideas that made Rome capable of building a vast empire were learned from the Greeks: the alphabet, the use of numerals, law, philosophy, and technology. And while Rome was never purely a democracy as Athens had been, the plebians (common citizens) usually had a powerful voice in government through elected tribunes and direct votes, and could not easily be ignored by the non-elected branches of Roman government.

I also wonder to what extent Homer's epics, the Iliad and the Odyssey, shaped Roman history. His epics, perhaps written around 800BC, had an enormous influence on Greek and Roman thought and perhaps even history. The characters in these epics primarily seek glory. They are fiercely proud, intolerant of the slightest insult, and hold that lineage and bravery were more important than the pursuit of wealth. Alexander the Great (300's BC) was greatly inspired by Achilles, and some believe that having Achilles as a role model potentially drove Alexander in his endless pursuit of territory, in order to attain immortal glory. Similarly, I wonder if this pursuit of glory over wealth was behind the fantastic ambitions of some of Rome's great expansionist leaders.

Another aspect of Roman tradition that drove its expansionism was this: one of the most effective ways of climbing the political ladder was conquest of new territory. For instance, Caesar's conquest of Gaul ultimately lent him the support needed to become the first emperor in 49BC.

Also quite important was the culture of self-sacrifice for the good of Rome. Two dramatic examples of this occurred during the battle to quell a revolution of Rome's Latin neighbors in 341BC. The battle was led by the two "Consuls" (co-leaders of the republic, with only one year terms), Titus Manlius and Publius Decius Mus. Titus sent a squadron of cavalry, with his son Titus among the leaders, to do some reconnaissance but with strict orders not to take part in any fighting. His son, passing close to the enemy lines, was taunted by an enemy commander. Against his father's instructions, he agreed to a jousting contest with the commander and killed him, as the remaining soldiers looked on. When Titus discovered that his son had disobeyed him, he said "Titus Manlius, you have respected neither Consular authority nor your father's dignity. I believe that you yourself, if you have any drop of my blood in you, would agree that the military discipline you undermined by your error must be restored by your punishment. Go, lictor, bind him to the stake." The army watched horrified as Titus' son's neck was severed on his father's orders. The other consul, Decius, made the ultimate sacrifice. After ascertaining from a priest that victory could be assured if only he would "devote" himself (i.e. commit suicide in order to persuade the gods to take the lives of your enemy as well), he said a prayer, leapt on a horse, and rode directly into the enemy's ranks where he was promptly killed. These stories give you an idea of the extent of the devotion of (some of) the ruling class to Rome's cause. Such a culture of self-sacrifice surely played a part in Rome's success.

So, to sum up, much of the success of the Roman empire was due to its inheritance of Greek traditions, strategic location, interest in expansion, tolerance of and interest in other cultures, and a relatively well-organized governing class that valued, at least earlier in the empire, devotion to Rome above self. Sounds a lot like some later empires and nations. I'm curious if relative tolerance (cultural/religious) is common to many great empires/nations (for instance, Mughal Empire, Alexander the Great's Macedonian Empire, Athens during its Golden Age, British Empire, United States). Though there are clearly lots of exceptions (the Spanish Empire boomed during the Spanish Inquisition).

Monday, June 13, 2011

Why Monotheism

I find this question fascinating: Why is it that the majority of the world's population is monotheistic? Is there some reason that monotheism is more attractive than polytheism? Or perhaps monotheism allows for a more successful empire? Or is it simply a coincidence of history? Or is it better rephrased as: Why are the two largest religions derived from Judaism?

Three thousand years ago, the vast majority of the world was likely polytheistic. Then Judaism developed, but was not widespread. Around 600's BC Zorastrianism (monotheistic) developed, and became one of the world's largest religions thanks to the spread of the Persian empire, but declined in 300's BC after Alexander the Great toppled the empire. So again by 0 AD there were very few monotheists. Today there are approximately two billion Christians and 1.5 billion Muslims, with a current world population of 6.7 billion (see here for breakdown).  By contrast there are 1 billion Hindus (polytheistic). There are around 1 billion Buddhists (Buddhism, in it's original form, is neither mono- nor polytheistic as the Buddha simply taught how to reach enlightenment but did not identify particular gods, however many later forms developed local deities and divine figures). In other words, monotheism likely developed relatively late in human history, yet now most people are monotheistic.

1) My initial thought is that monotheism has become more popular due to it being more reasonable to the rational mind than polytheism: For the modern person, science has come to explain most of the concepts that previously required supernatural explanation. A science-minded person tends to believe either in no god, or in an unknowable god that was responsible for the creation of the universe. For Christians, Muslims, and modern Jews,  God is similarly unknowable: God is judge, lawmaker, and can control events, but does not have a personality or form. (Granted, in parts of the Old Testament God has a personality, as when he walks in human form around the Garden of Eden, or argues with Satan about how faithful Job is, but these stories feel out of place compared to the usual sense of the formless and abstract God). Alternatively, in a polytheistic religion such as Hinduism or Roman paganism, gods are frequently less abstract and have particular personalities. For instance Vishnu is often pictured with four arms, riding on his eagle Garuda. (That said, Hinduism has a diverse range of thought and, unlike Roman paganism, has versions that are monotheistic.) In summary, it seems that belief in a single abstract god is less at odds with a scientific worldview than a group of personal gods with character and form. Thus it's not surprising that as the world has become more aware of the scientific viewpoint, we find that monotheism has become more popular.

2) While I really like the above idea, it is not really borne out if you look at the historical details. In reality, many people are Christian or Muslim as a result of historical empires and colonization.

Background: The Roman empire was pagan for most of it's history but converted to Christianity in the time of Constantine in 300's AD. Thus Europe became Christian. Then Europeans, through colonization and proselytization, led to Christianity in the Americas, large parts of Africa, Australia, and many smaller areas. Also, after the fall of the Roman empire in 400's AD, the eastern "Byzantine" half of the Roman empire lived on and was responsible for spreading Christianity to Russia. I am less familiar with how Islam spread, but generally it spread initially through the conquests of the Arab Empire in 600's AD (Middle East, North Africa, Spain), and subsequently through proselytization along Arab trading routes in South Asia,  Southeast Asia, and in parts of Africa.

 So our original question, why did monotheism become so popular, can partly be boiled down to Why was the Arab Empire so successful? (I don't know enough about Arab history to answer this), and Why did the Roman Empire convert to Christianity?

3) Why did the Roman Empire convert to Christianity? You might think it was political. Yes, Constantine converted to Christianity, enforced religious tolerance, and halted persecution of Christians throughout the vast Roman Empire. But leading up to this point, Christianity was spreading rapidly in spite of political opposition and persecution. So while later spread of Christianity can be explained primarily by political events, at least the early spread of Christianity was a result of organic growth. And why was Christianity spreading so quickly, at first mostly among the lower classes of the Roman Empire? This is a question with, I would guess, lots of contributing explanations. But I think it boils down to a) One of the tenets of Christianity is the importance of proselytizing, and b) Christian teachings were particularly attractive to the lower classes (i.e. the meek shall inherit the earth, a rich man is unlikely to go to heaven, Jesus is the son of a humble shepherd and focuses his teachings on lower classes, an eternity of happiness awaits you at death, etc.).

So how does this relate to the original question: why did monotheism become so popular? Is it a coincidence that Judaism, at first the only monotheistic religion of the Roman Empire, and a small minority religion, produced an offshoot that spread rapidly through the Roman Empire? And then produced another offshoot that led to Islam and the Arab Empire?

Jesus' teachings are thought by modern scholars to be heavily influenced by the Pharisee sect of Judaism that was growing in popularity during his lifetime. Some Pharisee writing, preceding Jesus' life, sound similar to New Testament teachings: "That which is hateful to you, do not do to your friend. That is the whole Torah." -Hillel the Elder, 1st century AD. "A learned bastard takes precedence over an ignorant High Priest." And the Pharisees, unlike their theological opponents the Sadducees, believed in resurrection of the dead. The Pharisees are considered more democratic than the aristocratic Sadducees. At the time of Jesus, the Pharisees were a minority sect among the Jews, but their philosophy turned out to be quite popular and shortly after Jesus' death would become the majority view of Judaism, and is the forebear of Rabbinic Judaism. Thus Jesus' teachings were not coming out of the blue; they were a development of contemporary Jewish ideas that were themselves evolving through theological debate within the Jewish community. 

Thus again we can boil down our original question partly by asking: Why did Judaism, via the Pharisees, produce this very attractive and self-multiplying version of itself where other contemporary religions did not?

To help answer this question, let's start by asking: How was Judaism different from other Roman religions? As the Roman Empire spread, the cults and gods they encountered were often incorporated into the Roman pantheon. People were free to continue participating in local cults as long as they agreed to participate in the traditional Roman ceremonies as well. Jews, initially the only monotheists in the empire, refused to worship other gods. At times this caused problems, but at other times they received special exemptions from the state. Thus Judaism was unique in that, through the fixed monotheistic dogma found in the Torah, it was not able to be assimilated like other religions. In fact we see that today, with Judaism being one of the oldest surviving religions in the world, despite numerous periods of persecution and exile. Thus it appears that monotheism helps a religion resist assimilation.

Is there a relationship between monotheism and proselytizing? Hinduism and Buddhism usually avoid proselytizing and believe there is more than one true way (Hare Krishna's are an exception). Judaism does as well. However, both Christianity and Islam believe there to be only one true way and place great emphasis on winning converts. It seems like an easy step to go from the self-confidence and immutability that is inherent in monotheism, to believing that other religions are incorrect, and thus believing in the necessity of proselytizing. Is this true? If monotheism tends towards proselytizing, then this would seem to be the key answer to the original question. Historically, most religions are polytheistic and most religions do not proselytize. However, the two largest religions worldwide run counter to this trend: both are monotheistic and proselytize.

In conclusion, I think the reason for the ultimate success of monotheism is likely related to its inability to be assimilated into other religions, its tendency to believe that other religions are incorrect, and its tendency to lead to proselytizing. (This is similar to evolutionary biology: genes spread that assist individuals in a) surviving to adulthood, and b) procreating. Dawkins would call monotheism a successful "meme.") In addition, it was incidentally helpful that the Roman Empire conquered Jewish territory, allowing an attractive and accessible offshoot of Judaism to spread throughout the empire, an empire that would be a major foundation for European and ultimately global culture.

I'm very interested to hear your thoughts. Please leave a comment.

Note that a previous version of this post incorrectly asserted that Pharisees proselytized. My evidence for this was very weak. Thanks to Esther for pointing this out.

Thursday, February 24, 2011

The Power of Practice

It's interesting how much one can accomplish with effective practice of a skill. I recently read an article by Joshua Foer, an author who, as an experiment, decided to devote himself to improving his memory. Over the better part of a year, he trained his memory to memorize long lists of numbers, the order of a deck of cards, poetry, etc. By the end of his brief but intense training he was able to memorize the order of a deck of cards in 1 minute, 40 seconds at the USA Memory Championship (a United States record).

At one point in his training he hit a plateau and wasn't able to improve his times. He spoke to his memory trainer, a psycholigist named K. Anders Ericsson, and learned the following:

"[Ericsson] found that top achievers [in any skill] typically follow the same general pattern. They develop strategies for keeping out of the autonomous [plateau] stage by doing three things: focusing on their technique, staying goal-oriented and getting immediate feedback on their performance. Amateur musicians, for example, tend to spend their practice time playing music, whereas pros tend to work through tedious exercises or focus on difficult parts of pieces. Similarly, the best ice skaters spend more of their practice time trying jumps that they land less often, while lesser skaters work more on jumps they’ve already mastered. In other words, regular practice simply isn't enough. To improve, we have to be constantly pushing ourselves beyond where we think our limits lie and then pay attention to how and why we fail."

Similarly, the way to get past the plateau we all reach with typing speed is to practice typing 10 - 20% faster than usual. By pushing yourself past "good enough" you'll make mistakes, learn to figure out what's slowing you down, and move past it.

It is remarkable that this author, with no particular aptitude for memorizing, using this intensive practice technique, became the US champion in less than a year. Practicing in this way is demanding and frustrating, and is not the way most of us practice. I wonder if some skills that we consider significantly based on innate talent (great skill at a musical instrument, solving math problems, learning languages, certain sports, juggling, creative writing, drawing, sense of humor) are more based on determined practice than we realize. If an average person can become a national memory champion in less than a year using this technique, it seems possible that most skills could be attained more quickly and more extensively than we realize.

Our minds are so incredibly plastic- so ready to tackle any challenge if forced to do so. Blind people can learn echolocation (blind man Ben Underwood can do remarkable things, such as play basketball. Armless people can do amazing things with their toes (i.e. play piano). Deaf people read lips. If you wear lenses that turn the world upside down, within a few days your brain turns the image upright. Oliver Sacks eloquently discusses this plasticity, and it's persistence into old age, in his article on the NYTimes website. Persistent challenge can be the key that unlocks the incredible potential of our brains.

What if intelligence (narrowly defined as problem solving ability, for instance as measured by IQ) is actually the product of something more basic, a long-standing determination to not give up when approaching problems? The repetitive challenges squarely faced thus sharpen the mind's problem-solving ability. My friend Luke recently told me his brother is raising their child using a new parenting concept in which you avoid telling a child how smart or intelligent she is. Instead you compliment her on her determination. By focusing a child's self-confidence on their determination rather than intelligence, when they come to a difficult problem they are more likely to keep working at it rather than get frustrated and stop.

There is something beautiful about honing the mind to accomplish seemingly unreachable goals. Such an accomplishment must bring with it a great sense of pride and meaning.

Thursday, January 27, 2011

Living Well

As mentioned at the end of the happiness post, all this talk of pursuing happiness seems to be narrow-minded. Are there times when making a decision that is likely to decrease happiness might still be the more noble decision? An article by philosopher Ronald Dworkin in the most recent issue of the New York Review of Books (http://www.nybooks.com/articles/archives/2011/feb/10/what-good-life/) addresses this question.

This article makes the case for a concept he calls "Living Well".  Living well means navigating life in a way that you can look back on with pride.  "In my own view, someone who leads a boring, conventional life without close friendships or challenges or achievements, marking time to his grave, has not had a good life, even if he thinks he has and even if he has thoroughly enjoyed the life he has had." If you agree with this statement, then you agree that a good life is not just about happiness, but about living life well.

So what does that mean? It's up to the individual. The interesting point is that some of the ways people might consider "living well" are actually counter-productive to happiness. Some possible examples of living well yet reducing happiness: Risking your life for a cause (i.e. David Cato, Ugandan gay rights activist, just murdered yesterday; or fighting for your country). Creating a business can be much more stressful and risky than working for someone else and may lead to unhappiness, but if you're proud of the business then that increases meaning. An artist who devotes his life to his art to his own detriment and without reward. Monasticism.

Rainer Marie Rilke in Letters to a Young Poet recommends to an aspiring poet a life of privation and social isolation in order to explore the depths of the soul and thus improve his poetry. "Therefore, dear Sir, love your solitude and try to sing out with the pain it causes you." In his letters, Rilke recommends the young poet single-mindedly pursue his goal of becoming a greater poet, with no thought to his own happiness. Suffering can be valuable in this pursuit. From this perspective, striving for happiness as a primary goal in life seems a bit vacuous. Similarly, in 1939 Pulitzer-prize winning playwright Maxwell Anderson wrote:
To the young people of this country I wish to say:
If you practice an art, be proud of it, & make it proud of you; if you now hesitate on the threshold of your maturity, wondering what rewards you should seek, wondering perhaps if there are any rewards beyond the opportunity to feed & sleep & breed, turn to the art which has moved you most readily, take what part in it you can, as participant, spectator, secret practitioner, or hanger-on & waiter at the door.  Make your living any way you can, but neglect no sacrifice at your chosen altar.   It may break your heart, it may drive you half mad, it may betray you into unrealizable ambitions or blind you to mercantile opportunities with its wandering fires.  But it will fill your heart before it breaks it; it will make you a person in your own right; it will open the temple doors to you & enable you to walk with those who have come nearest among men to what men may sometimes be.
Capitalist economists traditionally have focused on improving overall wealth as the primary goal for a nation. Some economists have recently proposed focusing on improved happiness as a nation rather than improved wealth (which seems obviously preferable). But what if even this is not the best metric? Is our focus on happiness cultural? Would this focus on happiness as one of the primary goals of life seem foreign to someone from a different era?

Wednesday, January 26, 2011

The Coincidental Beginnings of Agriculture

One question I have always thought interesting is why agriculture cropped up independently in Mesopotamia, China, North America, and central Africa, all between 10,000 and 5,000 years ago. Anatomically modern humans developed in East Africa something like 100,000 to 200,000 years ago. They then left Africa something like 80,000 years ago. For something like the first 100,000 years of our existence, we didn't develop agriculture, but within the past 10,000 years we developed it in at least 4 areas independently. What happened 10,000 years ago that created this shift?

There is no consensus on this question. Here are some relevant facts: 1) While technically the Earth's been in an ice age for the past 2.6 million years, we're currently in the midst of a relatively warmer time called an "interglacial" period. This warmer period began 10,000 years ago. Prior to that, from 110,000 years ago to 10,000 years ago, was a "glacial" period, in which glaciers covered much of Europe and North America.  2) There was a great number of extinctions ("Late Pleistocene Extinction Event") of large animals between 50,000 and 10,000 years ago. These extinctions tend to coincide with the arrival of humans into each animals ecosystem. For the most part these large animals were naive to human hunters and did not have time to evolve to be afraid of those spindly humans. For the most part this did not occur in Africa, where large mammals were exposed to human hunters from the very beginning and were thus able to evolve as the humans' hunting skills improved.

Everything below this  line is pure speculation.

It would seem that the almost simultaneous (geologically speaking) development of agriculture at multiple locations around the globe occurring soon after the last glacial period ended is not a coincidence. The changing weather and ecosystems that came with the warmer climate must have somehow led to agriculture. And with hunting becoming increasingly difficult as easy to kill naive large mammals were depleted, humans everywhere likely became increasingly dependent on plants for calories.

Another factor that may have come into play: once humans had spread around the globe, it is thought that human population reached equilibrium  at somewhere around one million people. Equilibrium of course means that humans were competing with each other for limited resources, thus human tribes were likely in close proximity to each other, fighting over territory, some tribes starving to death or being decimated by their neighbors, etc. In such an environment, agriculture would be ripe for development as, once it was developed, it would allow for much higher population densities. It seems that something about the end of the ice age combined with hunter/gatherer humans existing at maximum capacity must have led to the development of agriculture.

Another interesting point that I read about last year in The Economist was a computer model that demonstrated the importance of population density in maintaining knowledge. This model showed that in a non-literate culture, where technology is learned directly from other humans, knowledge will tend to be forgotten over the millennia if there is an insufficient population density to keep that knowledge alive. Thus perhaps the beginnings of agriculture may have developed in many different places at many different times, but couldn't survive to maturity unless it was in a region where lots of humans were living. Thus, it could be that something about the end of the ice age created better conditions for hunter/gatherers in Mesopotamia, China, and the Americas that allowed for higher population densities, thus allowing agricultural technology to mature.

The Contingency of Christianity

Background: I believe that there was likely a creative spirit of some sort, or "God," that created the universe, possibly with the intention of having intelligent life develop. There are two main questions that science is unlikely to ever answer: 1) How did the universe come about?, and 2) Why is it that I, and presumably all humans and most animals, experience "consciousness," i.e. awareness of my existence. Hence I believe in a higher power that's beyond our understanding. However, while I believe in God, I no longer believe in Christianity or any other religion.

One of the realizations that led me away being a Christian is how contingent my being born Christian was on world events. There have been many spiritually enlightened individuals over the course of human history, some of whom created new ways of living and believing. Moses, Jesus, Paul of Tarsus (without whom we would never have heard of Jesus), Lao-Tzu (founder of Taoism), Siddharta Gautama ("The" Buddha, founder of Buddhism), Bodhidharma (one of the fathers of Zen Buddhism), and many more that we've never heard of. The reason the current inhabitants of the United States are mostly Christian is because the US was primarily a British colony. Britain, while initially "pagan," became Christian because it was a part of the Roman Empire.  The Roman Empire was Christian in part because Emperor Constantius had a Christian wife (or concubine, history's not clear on this) who fathered his son Constantine, who, when he became emperor, was sympathetic to Christians since his mother was Christian. (Although it seems Christianity was gaining popularity in the Roman Empire pretty rapidly and probably would have become the dominant religion regardless of Constantine's tolerance.)  The reason Christianity was able to spread through the Roman Empire was because Jesus and Paul were part of the Roman Empire. If Judaea had not been conquered by the Roman Empire, or if the Roman Empire had never developed, Jesus would likely have been forgotten. If China hadn't stopped most of it's maritime explorations in the 1400's, North America might have been colonized by Chinese rather than British colonists. If that had happened the US might be predominantly Buddhist. There are probably thousands of religions in the history of humankind, and certainly more than one of them has important things to teach us. The reason I was born Christian is contingent on many historical events. It's counterintuitive to think that only one religion, the one I happened to be born into, is the only right one. There is no rational reason that one should have faith in a single religion. It seems that the only way to be Christian and still maintain rationality is to take the viewpoint of my Christian friend Peyton Bowman: "It may not be rational to be Christian, but I choose to believe in it because I am a stronger and better person for it."

Human Evolution

Humans have many traits that separate us from our closest relative, the chimpanzee. Thinking about the differences between chimps and ourselves can give us insight into human evolution. Some differences:
We have much less hair.
We have a shorter gut.
We are better at throwing objects accurately.
We have hooded nares.
We are weaker and slower than chimps.
We don't have fangs like chimps.
We walk on two legs primarily.
We have emotional tears.
We have more subcutaneous fat than other primates, that tend to store more fat around their gut.
We have more complex language and tool use, including fire.
How do we explain these differences? Was it a single niche that brought about all these changes, or a series of different environmental pressures over millions of years?

Everything below is pure speculation:

Our nearest living ancestors live in trees, so the first change in niche for protohumans must have been the transition to living on the ground, potentially in savannas. Chimpanzees are already pretty intelligent, and are known to use a variety of tools, though with their long fingers and short thumbs they have some difficulty with precision tool use. On the other hand, baboons, who live mostly in savannas, have hands that are better able to grasp objects, though do not use tools as often as chimpanzees.  Why not? Since chimpanzees are more intelligent than baboons, the most reasonable conclusion is that baboons aren't intelligent enough to significantly use tools. When protohumans made the transition to living on the ground full time, this allowed the hand to focus on adapting fully to tool use rather than tree-climbing. I think one reasonable conclusion from all these facts is that the major story of protohuman evolution is: There was an intelligent tree-dwelling primate, more intelligent than other primates, that made the transition to living on the ground, developed dexterous hands, and started using more and more tools, thus driving increasing intelligence. It seems likely that this increase in tool use created the pressure for bipedalism, allowing a greater variety of tool use (such as walking with a spear).
Once the protohumans started using more and more tools, many traits likely followed as a result. For instance, the use of fire for cooking is the likely explanation for the shorter gut as it takes less gut to digest cooked food (with cooking we basically externalized a portion of digestion, like a spider who injects digestive juices into his trapped prey). Perhaps our shorter hair is a result of our ability to create clothing out of the hides of other animals and warm ourselves by fire, thus making it unnecessary to spend the calories growing our own pelts. Our ability to throw objects accurately is likely related to hunting, perhaps with spears. We are weaker and slower since we can protect ourselves and hunt using tools rather than spend calories maintaining large muscles. 
There's an interesting theory call the aquatic ape hypothesis (http://en.wikipedia.org/wiki/Aquatic_ape_hypothesis). It states that at some stage, protohumans spent enough time in the water collecting food that it affected our evolution in a variety of ways. I think the most clear example of the explanatory power of this theory is our hooded nares, which keeps water out of the nose unless you turn upside down.  Other examples include reduced hair and increased subcutaneous fat, characteristics found in many mammals that spend lots of time in the water (subcutaneous fat is a better insulator than hair when wet).  Some proponents of the theory push it further, saying bipedalism developed to help protohumans wade in water while keeping their head above the waterline (when apes wade across rivers they do so on two legs).
Incidentally, early, anatomically modern humans did often live on beaches. For instance, the first wave of human migration out of Africa around 70,000 years ago or so, moved primarily via the coast of the Indian Ocean, arriving in Australia around 40,000 years ago. The fact that this first migration moved along the coast suggests they were beach-combers. Similarly, some scientists believe that once Asian peoples arrived in the Americas around 15,000 years ago, they rapidly moved down the Pacific coast, then later migrated inland, again suggesting a beach-combing society.
What was the driving force behind language? Perhaps for teaching tool use or planning for complex hunting and trapping maneuvers? And why music? And why does it seem our intelligence is so complex and adaptable, beyond the needs of a hunting/gathering society (able to develop quantum mechanics or play a Rachmaninoff piano concerto, for example)? Why do we laugh at humor?