A better question might be- were they? Comparing technological development is always tricky, because in the real world, there's no convenient way to boil down a civilization's technology into an easily comparable cipher. You can look at specific areas, but if I'm better at metallurgy and astronomy, and you're better at chemistry and hydraulics, who's more 'advanced'? There are also many subtleties and facets to development that we often overlook- an oft-cited example here is that early iron weapons were not materially an improvement over bronze ones, but benefited from the relative abundance of iron and the fact that only one ore was needed. So if I have bronze spearheads and yours are iron, does that mean you're more advanced, or is it just an accident of geography? Or maybe my folks have a more robust economy and administration that makes it easier for us to bring copper and tin together from disparate sources. It's hard to say, really.
A more topical example: I've recently been reading Bernal Diaz's work on the Spanish conquest of Mexico, and while he states that the Spanish armor and weapons were better than those of the various native groups they fought against, the advantage conferred was not as great as you'd expect, and numbers (which were generally on the side of the natives) tended to carry the day. So even in the realm of military technology, which is one of those areas where the Spanish had a clear advantage, the difference was not so great as to turn the tide of battles. Cotton armor and obsidian-bladed weapons may sound primitive, but I highly doubt you'd want to get on the bad side of someone who was so equipped.
Of course, the next question is, how were the Spanish then able to conquer so much territory, if their equipment wasn't all that inherently superior? That's something that you could write books on (and many people have)- it doesn't boil down to a few factors. The conquest of the Aztecs especially is a fascinating topic- Cortez was acting against his instructions, and managed to leverage his position as an unknown cipher in regional politics in order to create a coalition (aided, of course, by the general enmity towards the Aztecs, by their subjects and neighbors alike). It was about as far from "they showed up and won using their guns, germs, and steel" as you can possibly get.
The East-West axis of Eurasia versus the North-South axis of the America's was a fascinating part of Diamod's argument that may shed some light.
His comments on the biology of a seed are of particular interest here. A seed is coded to germinate when certain environmental conditions are met. The length of day light, the amount of moisture being introduced to the soil, ambient temperature and others all play a role. So crops packages are restricted on a latitudinal basis. Wheat farming works great at 30-60 degrees North or South of the equator. Not so great between 0-29 degrees because the conditions that trigger germination are not met.
So why is this important? Asia's massive East-West access contains oodles of arable land suitable for the cereal package (wheat, barley, rice) and domestic animal package (cow, pig, sheep, chicken) that originated in the cradles of civilization. They spread east and west and were readily adopted by neighboring civilizations along the same latitudinal axis.
In Eurasia, people from Portugal to Japan along this East-West continental axis grew similar crop packages, borrowing technology from one another, adapting their best practices through periods of conflict, competition and cooperation for thousands of years.
The North-South axis of the America's placed their inhabitants at somewhat of a disadvantage when it came to the diffusion of domestic cereal crop packages. The Maya and Aztec packages would not be suitable for the Great Lakes region and vice-versa. The Incas Andean crop rotation would flounder on the great plains.
While there was contact and trade, conflict and cooperation between the various empires, nations and tribes of the Americas, there wasn't as much exchanged in terms of agricultural know how and best practices. This lack of exchange translates into more labor intensive agricultural methods and less output.
One of the central themes of the work is that the more people in an area, the more complex the social organization. When a society becomes large in terms of population, it must also become more complex in terms of how resources are distributed. A sophisticated, well defined, imitated, duplicated, taught and learned package of agricultural crops and livestock conferred a major advantage to the inhabitants of the Eurasian landmass. That advantage translated into many benefits not enjoyed by their counterparts in the Americas.
Hope this helps or is of interest, good question too.
I kind of wish I could restart this whole conversation, since I think a lot of people are talking past each other.
Things nobody is claiming (to my knowledge):
Things I am claiming:
I'm entirely disinterested in extended debates about what it means to have 'power;' I get that there's an interesting philosophical debate to be had here, but if you're not comfortable characterizing (for example) Belgium as being in a position of relative power over the Congo in 1890, my perspective is that you're so far into a postmodernist fog that we probably won't have a productive conversation.
I think it's important to not mistake Diamond his arguments for value judgements or teleological thinking. While you could say that his theories were very much inspired by economic determinism and lacking in certain aspects, it's rather unreasonable to assume his position is one of perceived superiority. It's certainly true that he measures technological advantages in gradations in order to compare and analyze, but this does not imply teleological thinking. These gradations are simply an indication of how "effective" technologies were. He argues that the rather specific circumstances and chain of events of the European continent, pushed towards technological advancements -and even ideological ones- which made Europeans very adept at conquering. This does not mean that one was superior to the other, nor that the European technology in it's entirety was superior. It means that certain technologies used by the Europeans, nurtured by these specific circumstances, were very efficient at conquering others while the technologies used by the Native Americans, nurtured by their very own specific circumstances, were not very efficient at halting such conquest.
His thesis feels a lot like economic determinism, but once we nuance it with the concept of path dependence, it becomes a lot more convincing. As far as I know, it's still a very well-respected work.
Comparisons of "technological superiority" or "degrees of development" are deeply flawed. To say that European development was "better" than American relies on the assumption that there's some sort of teleological ideal of linear progression and ignores the reality that technologies exist within a given context. You simply can't say that X is better than Y unless X and Y were developed in the same context to fulfill the same need, which is never the case in disparate human societies.
To give an example, let's look at what might be regarded as a comparable category of technologies: Bridges. Specifically, modern American suspension bridges, Roman stone arch bridges, and Incan rope bridges. One might suppose that these are clearly listed in terms of "superiority", but examination of their disparate contexts reveals the supposition to be nonsensical. A suspension bridge requires more advanced metallurgy and engineering knowledge to construct, but is it better? It won't last as long without maintenance as the roman bridge. It can't be built as cheaply or easily in the steep, narrow heights of the Andes as a rope bridge. It depends upon existing in a social context in which large amounts of materials and cooperating tasks can be thrown at the problem. A stone arch bridge was the best technology to solve the problem Roman society needed to solve. A rope bridge is the best technology to solve the problem Incan society faced.
That's a purely demonstrative and rhetorical example but hopefully it shows the principle: You can't compare technologies independent of the contexts that created them and say that any one is "better" in an objective way than any other. Technologies are solutions to specific problems, and as such can't be more or less "advanced" except in the subjectively biased opinion of the society that created it.
To give this a more concrete grounding in reference to the question of pre-Columbian Americans, I'll refer to some points from Charles Mann's 1491, in regards to the New England Pilgrim's experiences interacting with native societies: • Moccasins were considerably more comfortable to wear over long distances than English boots, causing less foot injury and pain, and were better water-proofed • Deerskin robes protected from the elements better than the colonists' clothes • Maize yields more grain per acre than Old World crops • Native bows performed very favorably to firearms, after the initial "fear factor" of the noise and smoke was discounted. To quote the book:
When the Powhatan later captured John Smith, Chaplin notes, Smith broke his pistol rather than reveal to his captors "the awful truth that it could not shoot as far as an arrow could fly". (Chaplin 2001:111-12)
They also demonstrated greater accuracy and rate of fire. • The native wetu was regarded as "warmer than our English houses" and more waterproof. • The food package of the east coast natives was more nutritious and less prone to famine than Europeans were accustomed to, lending to the often awed descriptions of natives as tall, "beautiful of stature", and "as proper [...] for feature and limbes as can founde".
The idea that pre-Columbian Americans were "inferior", socially, culturally, or technologically, is a major misapprehension caused by a mistaken attempt at direct comparison of developments which are not comparable, and ignorance of American achievements.
edit: Sorry for the terrible formatting, both typographically and conceptually... I wrote this on a phone while pressed for time.
I am currently partway through reading the book Empire by Niall Ferguson, and even though it focuses on the building of the British Empire, I feel that it is relevant to this discussion. Specifically, I would like to address the initial foray by the British (and Dutch), into India.
First, I will start by saying that when the East India Company (as well as the Dutch East India Company) began building trading posts in India sometime in the 16th century, they were very much susceptible to both diplomatic and military pressure by the Indian powers in the region. Many trading posts were destroyed, and many British and Dutch were killed. So here the argument can be made that the power was actually in the hands of the Indians, and not the Europeans. However, the situation is much more complex than that. I cannot find the quote right now, but a paraphrase would be that "the British essentially took control of India by playing the Indian princes against each other". This is similar to what the Spanish did in South America. It was quite a while before British soldiers actually began fighting in India (in large numbers), as most of the early conquests were simply made by paying local rulers to fight each other, and instilling puppet governments. Regardless of the fact that the British had very few boots on the ground, they were still the power-brokers.
Regarding any actual technological gap that existed, again I cannot talk about 1492, but I can talk about 16th-18th century India. Simply put, the British had nothing to lose, and everything to gain (again, I'm paraphrasing from Empire). Their naval superiority over the Indian subcontinent could not be matched by any non-Europeans. Britain was able to land troops in India, but no Indian kingdom even had a chance of invading Britain. Despite their initially small technological lead (an early musket was not necessarily superior to a bow), the fact remains that the musket is much higher up on the path towards modern weaponry, and British military tactics and doctrine were also much more advanced. It is true that the influx of goods from Britain's colonies bolstered her power and technological advancement, but the question is asking about technology near the time when contact was first made.
In summary, when the British began making inroads into India, they did so by utilizing superior ships, superior weapons, as well as arguably superior diplomacy. I find that the situation in South America worked out quite similarly, at least in the sense that a European power sailed over and, using both superior force and diplomatic maneuvering, put itself into a position of power. As much as I respect the responses by many people here, the fact remains that the British (and the Spanish), had nothing to lose, and everything to gain, thus the idea that the colonial powers were not "dominant" is quite flawed.
Edit: I apologize for not answering the "why" part of your question, but I am not an expert on that, and most of the posts here seem to be trying to establish whether the Europeans actually had a technological lead. I would very much appreciate it if someone with some knowledge on European military technology would comment, as I myself am now quite interested about this.
Without getting too much into the Eurocentric racism of Guns, Germs and Steel (if you haven't already, see Michael Wilcox's excellent critique: "Marketing conquest and the vanishing Indian: An Indigenous response to Jared Diamond’s Guns, Germs, and Steel and Collapse"), the basic idea that Europe uniquely benefitted from its climate and geographic location is absolute bunk. It's only relevant vis-a-vis it's proximity to the Americas compared to competition imperial powers such as the Ottoman Empire. But more than anything, I think it's really important to provincialize Europe a little bit when thinking about these questions. As Kenneth Pomeranz argues in The Great Divergence, the actual technological levels of states in Western Europe were comparable to other large Eurasian state formations until the mid-19th century, and even then, the Industrial Revolution should be thought of first as a English phenomenon, and only later as a 'European' or 'Western' phenomenon. So, singling out Europe in 1492 as a model of human achievement in any respect is ahistorical. And moreover, Europe, as it was, was not isolated or cut off from the rest of the world. There was a steady flow of sciences and technologies passed along the silk road(s) and through north Africa and disentangling Europe from Africa and Asia to compare a set of civilizationally indigenous technologies with the Americas is basically impossible and is fool's errand. In other words, defining a silk road technology such as gunpowder as distinctly 'European' versus an indigenous 'American' technology such as the macuahuitl is extremely problematic.
And to push this whole point a bit further, there was no Europe in 1492 to start with. Europe, like the Americas, was not unified or internally homogeneous, and it's very ill-advised to attempt use these continents as a rubric for comparison. This is especially that case since many scholars (including unabashedly Eurocentric/right-wing scholars like Carl Schmitt in The Nomos of the Earth) point to the colonizer's discourses and ideologies regarding 'America' as having helped form the idea of 'Europe' as a distinct region or civilization in the first place.
Secondly, technology can't really be neatly defined as weapons and gadgets. If you're talking about math, astronomy, or other forms of knowledge production, or something less formalistic like agriculture, then there were in reality certain areas in the Americas that were more technologically sophisticated than certain areas in Europe in 1492.