Psychologically. We are parallel and with good reason.
I mean in a deeply psychological sense. In-depth, humans are parallel thinkers. Superficially, we look more like serial thinkers. We talk serially, for instance. That may be because we cannot say two words at the same time. We cannot write two words at the same time, nor can we gesticulate them. We are stuck in quite serial communication.
In our thinking, we also seem to be quite serial. At least, it’s difficult to follow two lines of thought simultaneously, whether outside or inside ourselves.
As far as we consciously know, we are rather serial beings.
Under the conscious hood, there is a different story.
Many things happen in our mind/brain/body simultaneously, in ‘parallel.’ In fact, any thought that reaches consciousness has been influenced by many mental elements. It has been a tortuous journey before coming out, for every single thought.
Of course, not always to the same degree. There are many (kinds of) differences inter-individually as well as within one individual. Time of day, tiredness, concentration…
Also: it depends on whether one is ‘expert’ in some domain.
A bit more surprising perhaps.
This may be science but it may also be daily life. An expert is someone who doesn’t think he needs to think much before an answer pops up in his mind. Thus, an expert can generally think of a solution more quickly than a layperson.
At the same time, an expert can be surprisingly inept at giving to-the-point reasons why or saying how he came to a specific answer. Time and again, he thinks he knows, but he cannot articulate it well. An expert has the expertise, but it is frequently hidden in parallel layers. Trying to serialize it brings unexpected difficulties.
Looking at the history of ‘thinking’
there is no surprise why much of this mental serializing can be tough. After some billions of years of parallelism, our ancestors started serializing only some million years ago and even then, very slowly.
This possibly coincided with the slow emergence of consciousness. After all, consciousness is about keeping distinct elements in focus so they can be communicated – here we have it again – inside one’s mind (between different brain parts) as well as between individuals. Note that both developed simultaneously and probably through mutual enhancement. Indeed, the serial stuff is the basis itself of any human communication, as well as consciousness.
So we don’t have consciousness for the sake of consciousness, but for the goal of communication. Including for communication with oneself… which is, then again:
In the meantime, we didn’t lose what had been built up for billions of years. And that’s a good thing because as living creatures with the history that is ours, we need parallel thinking in order to survive every minute of the day. Without it, we wouldn’t be able to accomplish anything.
Because we are humans.
Artificial intelligence may be completely different.