Question: In my world human(oid)s are not born anymore, they are grown in pods which mirror the conditions of a natural womb.

Children are educated before birth and are "born" as fully mature adults with a standard education ready to join society.

How long would this process take? I assume that artificial growth could be much quicker than a natural 18-20 year period. Could a human be grown in a year? A decade?

Answer: 
It **REALLY** depends on what level of technology we're talking about here.

After all, given sufficiently advanced technology, we could "build" a person, atom by atom, to have all the same properties, education, mental and motor functions etc. as if they had developed the normal way over many years.

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Let's assume a level of technology that allows us to "develop" the brain in any way we like (including but not limited to: memories, knowledge, motor functions) as the body is growing, but which requires all the normal physical/chemical processes to take place. Albeit in an environment designed to optimise the speed/efficiency of that development.

**My guess: 2-7 years**

This is based on the fact that the environment you describe (No external interruptions, wholly optimised for and focused on development) sounds *very* similar to what we call "sleep".

Now, sleep also involves lots of other functions relating to ongoing maintenance/learning/repair which we may be able to eliminate the need for in our growth environment.

But then again, we have almost no idea of \*why\* humans need to sleep in the first place. So, I would suggest, for every day of "normal" growth, you will need a significant fraction of the time we spend sleeping, 2-8 hours or so, of "Test Tube Development Time". This yields 9%-33% of "Normal Development Time", so 2-7 years for a 20-year-old equivalent.
Human growth is subject to many limiting factors, including the ability of the mother to supply the required nutrients to the foetus, and after birth, the ability of the child to acquire the full range of expected social skills.

A young human is physically small in order to convey the impression of youth to other humans. Since learning to be an adult human takes around eighteen to twenty-five years, that is how long it takes for the human body to mature fully. Size and other physical traits conveys an impression of age to others.

Now, if humans could grow to maturity and be born with all necessary knowledge to be fully functioning adults, as well as be free of the limitations of maternal nutrition, growing such a human in-vitro could occur in a relative short period of time.

In larger mammalian - and dinosaur - species where achieving an adult body-size (of several hundred kilograms to many tons) as quickly as possible is of paramount importance, very high growth rates can be achieved, with newborns achieving maturity within a handful of years, certainly within 5 years or less.

We could therefore expect that with genetic engineering - or some clever artificial stimulation - to remove the limits on pre-maturity growth-rate, a fully mature human could be produced within three years.

I should point out that if humans were genetically engineered to grow that quickly, it would effectively sterilize the population and make them dependent on artificial reproduction. Should a modified human mother become pregnant, her body would not be able to supply the huge metabolic needs that such a foetus impose on her, and a significant or even fatal loss of body mass would likely occur. Should the foetus survive, it would be no better educated than any normal human newborn.

On the other hand, if humans were grown rapidly and educated in-vitro through medical trickery rather than genetic engineering, a natural pregnancy would most likely be possible, with a normal-sized infant being born after the usual period of gestation. It is up to you if the mother would have been educated sufficiently to have the knowledge to handle a naturally-born child.