What's the Connection Between Optimism/Pessimism and Positive/Negative Self-Talk?

A friend always responds to my inquiry about her well-being, "I'm good." There's usually a small addition. "I'm busier than I like to be this time of year, but the project is going well," or "My cold is getting better every day." She's not chirpy or smiley, never smarmy or gushing. She's real — and has apparently chosen or was chosen by her genes to be an optimist. She doesn't appear to be a positive thinker, in the over-the-top vein, but she does say positive things about her life, her work, the weather, the future.

My friend doesn't say negative self-talk out loud, even if she perhaps says it to herself. She occasionally makes some pessimistic statements. e.g. "I'm worried about all the changes on the job. It may not work out for me." Or, "I'm disheartened by all the conflict. I'd like to escape it." From my perspective, she's real; a realistic thinker rather than a particularly pessimistic or overly optimistic thinker.

Here are two quick definitions from The New Oxford American Dictionary, Second Edition so we're speaking the same language.

Pessimism - a tendency to see the worst aspect of things or believe that the worst will happen
Optimism - hopefulness and confidence about the future or the successful outcome of something 

I have been unable to find solid research about gender and optimism/pessimism. e.g. Are men or women more likely to be either optimistic or pessimistic? Or to find research related to the ratio of negative self-talk to positive self-talk for optimists as compared to the ration for pessimists. If any readers have facts, or opinions, I'd like to hear from you

 Here are some of my hypotheses (educated(?) guesses), based on my experience as a therapist and an intelligent woman, and on research of related topics.

• More women than men are optimists. Research shows that optimists live longer than pessimists and statistics show that women live longer than men; a correlation, but not necessarily a causation.

• Although women do more negative self-talk than men, they don't necessarily do negative thinking about anything except their own perceived inadequacies. And they do less NST as they go from teen years to the their fifties and sixties. Yes, it's damaging, but it doesn't make them pessimists. They could have hope for all else but themselves, so they're not pessimists or optimists. They're in the middle.

• Many men seem to get particularly pessimistic as they get older. I'm led to wonder if this shows that they have been pessimists all along, but have kept it under better wraps. As they age, they are more comfortable being grumpy/grinchy; a stereotype.

Does it matter? What do you think? What do you know from your experience or research?