I don't know that most or any of us are attempting to be dishonest or defensive. I think that we wind up straddling that line, though, when we recognize that we will be met with hostility. Whether it is the right thing to do, maybe not, but unless one has a tough skin or feels okay with other parents being hurt, it can be very, very hard.
Like a pp mentioned, one of the people I really tried to avoid telling was a mom who I believe is insecure. There were years of comparisions btwn our kids to the point that it damaged not only my relationship with the other parent, but the kids' relationship such that they really aren't friends anymore. Dd got really tired of being quizzed on what she could do and being told, falsely, that the other child was one upping her on everything when she responded honestly. Honesty hurt this other parent's feelings.
I thought about it a lot and really don't think that there was malintent. I also came to the general conclusion that I was being unkind by being totally upfront about my dd. I also had to realize over time that I could not allow my other dd, who is a less obvious HG kid on the surface, to be thrown under the bus, which is what happened after it became more and more clear that my other one could not be 'kept up' with. I've been a bit more upfront about my less traditional high achiever's abilities b/c I don't want her to be the consolation prize a la 'at least my kids are smarter than her other child.'
My point is that, while my children's self image comes first, I try not to be blatently honest when I don't need to be if I am aware that it is going to damage someone's already fragile self image or set off another round of parental competition.
