The pamphlet at hand: Engels, The Part Played by Labor in the Transition from Ape to Man, is here
http://www.marxists.org/archive/marx/works/1876/part-played-labour/

If you wish to skip through this fine pamphlet, you can; just do a search for "language" and the section pertinent to the discussion regarding language acquisition comes up.

It was no small feat that Engels used what little anthropological and archaeological data was available to him in the late 1800s to formulate insights into cultural and physical/intellectual evolution that have held up in general remarkably well.  There are a few speculations in The Origin of the Family, Private Property, and the State that we know now aren't true--the earliest humanoid species didn't live in the trees, there's little evidence of early human group marriage, and there is no correlation between brain size and intelligence, for instance--but overall The Origin of the Family and the Role of Labor are rare materialist analyses and both well worth reading, along with the later anti-racist evolutionists like Leakey, Gould, Richard Lewontin, and Eleanor Leacock, among others. 

In the age of the frightening medieval flat-earth anti-evolutionists, and the rise of anti-scientific religious nationalism, we should fight for the study of basic evolution which is under serious attack. Very, very few of my students at SDSU (all of them have undergrad degrees) have been able to explain evolution to me, even in rudimentary ways. They do not study Darwin. Nor Marx---those being two of the greatest thinkers of the last 200 years.

It is no mistake these people who are en route to k12 classrooms know nearly nothing about history (in the CSU system, unless you have the time and money to take electives, you will never encounter a post Industrial Revolution history class in the liberal studies, ie, pre-teacher, programs), nearly nothing about their own location inside the social relations of capital, and nearly nothing of science. Its a success of the system working, not an aberration.

It's a drag to take time away from other struggles to counter people who believe that if you sail too far away from shore you'll fall off and be eaten by dragons, but that's where capitalism is these days.

Engels made some errors in this early work.

It's true that humans aren't the only organisms to use objects for survival, but the fact that a few animals use ready-made objects to obtain food--chimpanzees using sticks to get bugs from inside trees, otters using stones to open clams, or birds building nests or beavers building dams--is not the same as making tools.  In none of these instances does the use of the object seem to increase manual dexterity or eye-hand coordination and would not therefore play a role in evolution as labor did in the evolution of simians to humans.  (In fact these few examples have sometimes been used by the popular bourgeois science press to 'animalize' human beings and put a biological spin on human behavior, which deserves to be always opposed.)

What has put Engels' original concept in a larger perspective, though, has been the analysis on the part of paleontologists like Stephen Jay Gould and Richard Leakey that we can't just consider the physical characteristics of labor in the evolution of human beings, that it's necessary to look at the interaction of pre-human species--the need for collectivity--in looking at the development of the brain, thought, language, tool making, protracted child rearing, etc. 

Pre-human species like australopithecus had few defenses or means of survival as an individual organisms (being rather small and slow of movement without natural defenses like fur, speed, claws, etc.), so it was only by working as a group that survival and development was possible.  It doesn't contradict Engels per se, but it does show that the role of labor wasn't enough by itself for humans to evolve, it was part of a larger, collective process. 

It is worrisome, though, that the concern about reading, language acquisition, etc, rarely gets to the question of the substance of what people read, why one would want others to read, etc and just what is it that we would want a literate person to think and do. It is assumed that reading in and of itself is a good thing. The form is interrogated. The essence is not; yet they only exist together.

I am not opposed to reading. I do a lot of it and hope that I am not too damaged.

However, among the most literate societies in the world in the early 1930's were Germany and Japan. Reading can be a Trojan Horse. House slaves were routinely taught to read, as were other slaves, so they would turn about and better oppress other slaves.

Reading, like social studies today, is largely reading about killing people.

The task at hand, as I see it, is to connect reading with reason, and reason with power, on the side of the interests of the many, against the interests of the few.

In the words of my good friend, Wayne Ross, at a recent NCSS conference: Read Marx. Make class war.

That's not sectarian. It's a good idea.

And to the Donner Five: Two words rise from the study of fascism that I have done recently, particularly the study of the work of Vasily Grossman, a Soviet writer who marched with the Red Army from the seige of Stalingrad, to Berlin.

Love and Revenge.

best r