The future is not the realization of our hopes and dreams, a warning to mend our ways, an adventure to inspire us, nor a romance to touch our hearts. The future is just another place in spacetime. (more)
Our minds have two very different modes (and a range between). We model important things nearby in more detail than less important things far away. The more nearby aspects we notice in a thing, the more other nearby aspects and relevant detail we assume it has. On the other hand, the more far aspects we see in something, the more other far aspects we assume it has, and the more we reason about it via broad categories and relations. (More on near vs. far thinking here and here.)

Since the future is far in time, thinking about it tends to invoke a far mode of thought, which introduces other far mode defaults into our image of the future. And thinking about the far future makes us think especially far. Of course many other considerations influence any particular imagined future, but it can help to understand the assumptions your mind is primed to make about the far future, regardless of whether those assumptions are true.
For example, since we expect things further away in time to also be further away in space, we expect future folk to live further away, such as in space, and to habitually travel longer distances. Since the distant past is also further away in time, we also expect past folk to live further away and travel longer distances, but the many concrete details we know about the past reduces this effect.
Since blue light scatters more easily than red, far away things in our field of view tend to look more blue. So we expect future stuff to look blue. And since blue stuff looks cold, we expect future stuff to look cold. Finally, since we expect far away things to have less detail, we tend to imagine them with fewer parts and flourishes, and less detailed textures and patterns. The future is not paisley.
And in fact, if you Goggle “futuristic style” images, you’ll tend to see images like those in this post – simple, smooth, cool, blue, and sky/spacy. In a word, “shiny.”
We also tend to assume there are fewer relevant categories of far things. So we’ll tend to assume future folk have fewer kinds of food, furniture, cars, houses, roads, buildings, and land uses, whose styles of use vary less from place to place. Instead of seeing a million variations bleeding into each other in dizzying complexity, we tend to assume there are fewer more discrete types, with less variation within each type and larger differences between types. For example, futuristic movies often have everyone wearing very similar clothes.
Another example is that we tend to assume future creatures are divided into relatively distinct groups whose internal divisions are less important. And since creatures that are more different seem further in social distance, we expect future groups to differ more from each other than current groups. So we expect eloi vs. morlock, romulan vs. klingon, ape vs. human, human vs. robot, etc.
Far tends to be happy, and high in status, power, and confidence. Conformity and obeying authority is near, but supporting underdogs is far. Sex, money, and temptation tend to be near, while love, satisfaction, trust, and self-control are far. So we often assume future folks have forgotten how to have sex, as in Sleeper or Barbarella, or that money motives are less common, as in Star Trek.
In far mode we tend to focus more on our simple abstract ideals and values, relative to messy desires and practical constraints. We also tend to neglect our messy internal contradictions and conflicts, and therefore assume our values and actions are coherent and consistent. So in far mode we tend more to explain good acts as virtue, and bad acts as vice or evil. We assume future folk are less driven by base desires, more strongly committed to their ideals, less tolerant of domination, more morally enlightened, and more morally judgmental about others’ failings.
We therefore tend to assume that future folk feel relatively moral, confident, and strong, and that future groups have less trouble coordinating to achieve common ends (making us especially blind to coordination being hard). So we can more easily imagine stark uncompromising conflicts between distinct future groups. Of course robots will war with humans, we think. And since we tend to feel more moral and uncompromising about the future, we more accept future uncompromising self-righteous conflict, relative to such conflict today.
Math and logic analysis is near, while creative analogy is far. So we tend to reason about the future via analogy rather than precise analysis, feeling more comfortable using metaphors and broad concepts like “exploitation”, “progress”, “boredom”, or “intelligence.” Math models of the far future are quite rare. Far mode minds tends to be more confident in the trends or theories they use, making them especially confident in trends and theories used to forecast the far future. Rather than seeing our theories about the future as weak all-else-equal tendencies, we are tempted to see them as absolute laws with rare exceptions.
We also tend to assume that future folk themselves rely more on analogy than analysis. They may have great tech, but we tend to see it arising more from rare sparks of creative genius than from vast armies devoting decades of attention to mind-numbing detail.
Likely familiar events are near, while unlikely novel events are far. So we think it more likely that “there be dragons” in distant lands. Scenarios that would seem too unlikely to consider today can seem reasonable possibilities for a far future. In fact, we may well reject future scenarios that don’t seem strange enough.
While we tend to imagine that trends during the future will be followed with few deviations, we are pretty willing to believe theories which predict that today’s trends, even long term trends, won’t continue into the future. For example, even though natural resource prices rarely rise, we are willing to believe theories that resources will soon “run out”, so that prices greatly rise.
Since important things seem nearer to us, stronger emotions feel nearer, and so we have weaker motives and emotions regarding far things. Instead of being filled with elation or terror regarding good or bad things that might happen in the far future, we tend to treat such events more philosophically, and to assume future folk will do so as well. In a scene from Monty Python’s Meaning of Life, a woman is willing to die to donate a liver after she’s seen how vast is the universe. Similarly, in far mode even human extinction may seem no big deal; “it was our time to go.”
Tasting and touching tend to feel near, while seeing and hearing tend to feel far. So we mainly imagine what the future looks and sounds like, relative to its taste or touch. Words and polite speech tend to be far, while voices, grunts, and slang tend to be near. So we more often imagine future folks’ polite words than their earthy sounds. We imagine future folk being relatively cerebral – we see them as relatively patient in listening to long intellectual speeches, and less often imagine their grunts or wild passionate music.
Of course it remains possible that many of the above far-mode-based expectations about the future will be realized. Maybe stuff in the future really will be simple, smooth, blue, and cold. Maybe future creatures will be spread across space, habitually travel far, and be divided into a few distinct types that vary greatly between types, very little internally, and coordinate well to achieve group ends. Maybe future folk really will be more driven by abstract ideals, with moral judgements driving uncompromising self-righteous conflict between groups. Maybe their innovations really will come from a few geniuses. Maybe the future will be very strange, yet is predictable from powerful theories available now. Maybe future trends really will have few deviations, and future folk will accept their demises philosophically. But please at least consider the possibility that you expect such things not because you have strong supporting evidence, but because your mind was just built to expect such things.
Added: Coincidentally, I was just quoted in this NPR article saying the future isn’t what it used to be.
The future is higher quality. The future is uncertain. Therefore the future is a trade-off between quality and uncertainty.
You said we expect people to live further in space. Distance is farther, metaphorical distance is further.
I expect us to live in cycles, as we always have. A renaissance here, oppression there, resistance will dominant anything new that doesn't offer convenience. Our next likely scenario will be worldwide catstrophe followed by technocracy ruling over labor slaves. Basic commodities are being depleted at an alarming rate. It's almost inevitable. Human rights and other fine rules are likely to go out the window as nations crumble under the weight of governing a human surplus while attempting to control increasingly scarce resources. The time to overcome it is NOW. We must actively safeguard human rights and fight to conserve pottable water, wood, access to iron, oil, rare elements to see they are no longer squandered to keep stocks viable. And thats only the beginning.
We may not outlive our next pass through the cosmic cloud. Spacefaring is more than an ideal, it's virtually a must. Even colonies in orbit may ensure the survival of the human race, come another planet killing asteroid.
But deciding what the future holds is a question of time. And thats like trying to decide how to handle a snake you can't see well enough to be sure what kind or how big it is. With your bare hands. Pronto.