One of the surest ways you can treat other people as objects is to believe too strongly the stories you have about them.
“He doesn’t care”
“She’s only interested in herself”
“He’s so frustrating”
“She’s so fixed in her ideas, it’s impossible”
“He’s a loser”
“He’s so caring”
“She knows about everything”
“He’s so strong – nothing gets to him”
It’s not that your stories have no truth to them.
But people are so much more vast and mysterious than you can possibly know, and changing all the time. Any story you have is, in a significant way, partial and instantly out of date.
If you’re committed to treating people as people, you’ll have to start taking all this into account. You’ll have to loosen your hold on your stories. That way you’ll have a chance of encountering the person that’s actually there, rather than the idea of them you’re so determined to hold on to.