I was waiting for the author to cite some concrete examples of how we might feel differently about people from the 19th century, but his observations were general.
Some of the ways they were different...
Attitudes towards women - could not even own property in many cases. They were expected to be completely under the control of a man - and to direct their energies to supporting the man and the family. (Ok, things haven't changed everywhere... but a lot has changed.)
People's attitudes towards government and its role have changed... It wasn't expected in the 19th century that the government would perform disaster relief in cases of floods, fire or hurricanes. Churches and other charitable organizations were the safety net for the disadvantage - if they had any at all.
People's view of their place in the universe - when they looked up, what did they see? Almost all of what we know of the Universe was discovered later, and it effects the way many people look at things.
It is my impression that people were more religious in the day - at least outwardly. I think it was unusual to not belong to a church ( or mosque or temple) in those days.
Others?
P.S. It also occurs to me that different segments of our society have changed at different rates than others, and that any given attitude or point of view can still be found here and there today.