zengardeners's thoughtful point by point post above prompted me to consider the challenges myself.

Read a novel

Of course not. They've not been taught to read so the written word is a useless form of communication. However, after tuition, they can communicate with humans with sign language. Can you communicate with sign language? I can't.

Reflect on his own existence

Certainly. They can let us know when they're hungry, bored, tired.

Enjoy a Shakespeare play

Homocentric view. Do you enjoy ape mating rituals? Also, I don't enjoy Shakespeare.

Wonder about the meaning of life

See reflecting on existence.

Appreciate a Beethoven symphony

Homocentric view. Do you enjoy ape grooming rituals? They can certainly appreciate music - studies show it can be soothing or agitating to apes. Much like humans. Besides, you're lumping apes here in the same category as teenagers.

Think about the theory of evolution

As was amusingly pointed out above, neither does half of America. Nor does a three year old.

Dream about his future

They do. Those that have learnt sign language have not only reported on their dreams, but also recognise that they are dreams.

Perceive right and wrong

Again, they do. And they know when they've done wrong.

Complete a crossword puzzle

Homocentric view. Can you determine your status in a pack by decoding the complex clues relating to heirarchy? Also, read Köhler.

Contemplate the size of the universe

They're certainly aware of differences in scale, which is all this is.

Form a mental concept of God

They can certainly form superstitions; a certain coloured food tray is bad, another one good. Also, given that no human has ever given a coherent definition of god I hardly think we can berate apes for this.