Explain Mala’s statement that Vladek is “more attached to things than to people”. How does Art react to this?

Mala knows that Vladek is a hoarder. Vladek hasn't let go of his experience during the war. He keeps things like his life depends on it. He identifies with possessions to give himself a sense of place and understanding. Vladek has much more trouble with dealing with the present and the people he has to deal with.