Some time ago TI~s has considered the question of characterizing B (G), and more generally, of finding the automorphisms of bounded displacement of G, particularly when G is a connected real Lie group. Our purpose here is to extend these results to various other cases as well as to deal with the analogous questions for 1-cocycles. We concern ourselves, among other things, ~vith the question of sufficient conditions for B(G)-~ Z(G), the center, or more generally, for G to have no non-trivial automorphisms of bounded displacement. The significance of such conditions can be seen in work of the author together with F. G~EE~LEAF and L. ROTHSCHILD where, for example, the Selberg form of the Borel density theorem is considerably generalized. These conditions are therefore closely related to, but not identical with, sufficient conditions for the Zariski density of a closed subgroup H of G with G/H having finite volume, see [11]. For this reason it is enlightening to compare these results with those of [11]. On the cocycle level, we give sufficient conditions for the points with bounded orbit under a linear representation to be fixed and more generally, for a bounded 1-cocycle to be identically zero. These conditions actually play a role in [11]; they are among the sufficient conditions necessary to establish Zariski density of H in G. We also deal with certain converse questions and applications to homogeneous spaces of finite volume. For example, if G/H has finite volume and a is an automorphism of G leaving H pointwise fixed, then a has bounded displacement. If ~ is a 1-cocycle and r I H is trivial, then ~0 is itseff bounded. w 1. In [13] TITS has considered the question of characterizing B (G), and more generally, of finding the automorphisms of bounded displacement of G, particularly when G is a connected real Lie group. Our purpose here is to extend these results to various other cases as well as to deal with the analogous questions for 1-cocycles. We concern ourselves, among other things, with the question of