I'm more concerned about the strength of handshakes. I have a bias against anyone who actively squeezes my hand with anything beyond a simple, firm grasp. It comes across as macho, like you've got something to prove, and therefore untrustworthy. I'd like to point out here that I'm admitting a bias rather than expressing an opinion. EDIT: at least now I'm approaching something resembling adulthood I don't have the pro…
Any time someone tries to crush my hand I instantly feel apprehensive of them, as you describe. But perhaps some of them don't actually realise how hard they're squeezing.