[eah13]

I'd say human language is the superset of artificial language and natural language. Though the artifical/natural labels are a poor fit.

Experience is a big factor, but I think there's a limit to the amount of language learning most 50 year olds can undergo, even in a decade. But luckily for us we agree young exposure to code is a good thing :)

[delluminatus]

> [...] there's a limit to the amount of language learning most 50 year olds can undergo, even in a decade.

I wonder why you think this is true? I have personally never been given any reason to believe that a 50 year old is any less able to learn a language than a 0 year old. In fact, if you took a 50 year old and dumped them alone in a foreign country and gave them one or two dedicated language teachers and left them there for many years (which is the environment in which most children learn a language), I expect they would learn the language just as well as the child, if not better.

[eah13]

http://scholar.google.com/scholar?q=language+learning+rates+...

It's well documented that the median language-learning speed/ability of younger people is greater than that of older people.

[delluminatus]

Hmm... maybe this is just me not being familiar with the literature, but from that link, it looks like there are very mixed results (some studies report no difference based on age of acquisition, whereas others report that children learn more quickly/effectively). It does seem like the percentage weighs in your favor though, so I suppose I should adjust my beliefs on the matter.

[abvdasker]

I have some personal experience that suggests otherwise. A close relative of mine aspired to live in France for most of her life, and after a divorce she decided to pick up and move to Paris at the age of 48. When she first moved her French was quite bad, and Parisians would regularly switch to English when they heard her broken speech. Fast-forward to 8 years later and she is now fluent to the point that she's able to take on clients to her psychotherapy practice who speak only French. Her accent could use some work, and it took 7 or 8 years of complete immersion, but I don't know that there's any hard "limit" per se, to what someone can learn at 50 — it just takes longer.

[eah13]

Sounds like your relative had an above-median learning rate. But a median 10 year old could likely learn a new language to fluency in even less time.