The interaction of a polymer bearing beta-cyclodextrin moieties (beta-CD polymer) with poly(acrylamide)s bearing aromatic side chains was investigated by viscometry to study the effect of collectivity (i.e., interactions at multisites) in macromolecular recognition. The formation of inclusion complexes at multi-sites caused a large difference in the size of interpolymer aggregates, even though the difference in association constants for complexation of native beta-CD with guest moieties was not very much large.