I will forever judge you as weak and manipulative if you use that underhand handshake when introduced to me
Why are you so sensitive that the way I shake your hand could make you feel that way?
Something about that handshake just seems underhanded. And what kind of person would want to make a first impression like that?
While I get that it's hard to change first impressions you should try not to judge people until you truely get to know them. Give them a fair shot at being someone who you might like. You'll likely learn you have much more in common with people than you think.
What if I don't judge you like that?
Well that's certainly a start, but you really need to stop judging everyone on simple things like a handshake. You can't tell by a handshake what kind of person someone is.