Hangman with Generics

I'm implementing a hangman game, which uses a HashMap to store a character and result of the character guess.

public abstract class Guess{}

public class CorrectGuess extends Guess{}

public class FailedGuess extends Guess{}

public class Hangman {
    private Map<Character,Guess> state = new HashMap<Character,Guess>();
}

I want to be able to get a list of the various correct and failed guesses, so the details can be displayed.

The nasty solution i've currently got is to use "instanceof", but i feel this misses the point of using generics.

// the calling code looks something like
void display()
{
    hangmanDisplay.display(getFailedGuesses());
    consoleDisplay.display(getCorrectGuesses());
}

public List<CorrectGuess> getCorrectGuesses()
 {
  List<CorrectGuess> list = new ArrayList<CorrectGuess>(secret.length());
  for(Iterator iterator = state.values().iterator();iterator.hasNext();)
  {
   Guess guess = (Guess) iterator.next();
   if(guess instanceof CorrectGuess)
    list.add((CorrectGuess)guess);
  }
  return list;
 }

public List<FailedGuess> getFailedGuesses()
{...}

I want to be able to use the generic parameter type to control what is added to the list.

// the calling code would then look something like
void display()
{
    hangmanDisplay.display(getGuesses(new ArrayList<FailedGuess>()));
    consoleDisplay.display(getGuesses(new ArrayList<CorrectGuess>());
}

/**
 * get all values of generic parameter type T in the HashSet and add to the list.
 */
public void getGuesses(List<? super Guess> list)
{
    state,values().iterator();
    // how can i compare the type thats in the iterator.next() with the type defined by T in the input parameter?
}