Women tend to write "I think, it seems to me, in my opinion" type statement more often whereas men tend to write "It is, it will, the situation is" statements more often.
You remember in the last pub I was reading Revolution From Within by Gloria Steinem? Well, when she went to a reunion of some of her old friends from there they, to a woman, said "It is, I will, etc". They were all blue collar workers who'd spent their working lives in jobs surrounded by men who they treated as equals.
At the reunion of her college friends they all, to a woman, said "I think, it seems to me, etc", and the vast majority of them had left college and married men with well paid white collar jobs which didn't require the household to have a second income.
So it's nurture not nature. Fwiw, I tend to use both sets of sayings.
I recommend the book btw, it's written in a really conversational style but makes you think.
Thanks for the shiny new pub Fib, it's lush.