Data Pull vs. Push OOP Approach

Question

When I design my system from scratch, I often face a dilemma whether my object should push information into another objects OR whether the objects should

Answer 1

First, the general guideline clearly is: objects are data and behavior. This encourages less getters and so less pulls by providing methods which do something with the internal data.

Alone "push is better" (in the accepted answer) can't quite work as a push-operation in some class can require a new pull at the pushed object. Instead the best practice should be adding the push operation where it fits the abstraction best. This can even lead to a new more abstract class / composition of classes (see Object-Oriented Design Heuristics, Riel, 1996, p. 37 f.).