AbstractThe logistic model expects: If an item is told and heard in a set of people and periods under conditions of steady, pairing off, with equal opportunity, thenΔt=kptqt, i.e. increments in knowers are proportional to joint probabilities.Unequal opportunities result (among many causes) from“clique effects”where people communicate more within their daily circles of contacts (in homes, work, transit, eating and in leisure or other activities) than between such cliques.We hypothesized that if cliques are randomly overlapped in membership, then as clique size increases from 2 to allNpersons, the diffusion-retarding effect of clique barriers will tend to vanish.“Larger cliques accelerate diffusion.”Previous experiments confirmed this hypothesis up to 4-man cliques and contradicted it thereafter, as larger cliques exceeded logistic expectations, and did so systematically. This was due to a constraint of“seeking out non-knowers”which was eliminated in the present experiments.With three replications from a population of playing cards, simulating increasing sizes of cliques, the curves rose steadily towards the logistic as upper limit just as hypothesized. The parameterricmeasuring agreement of observed with expected increments rose from zero for the 2-man cliques up toric= 0·98 for theN-man clique-of-the-whole.From this and other experiments, we infer that logistic diffusion of items is likely to be approximated in so far as populations are homogeneous with very diversely overlapped cliques which are larger than pairs. As cliques enlarge, the diffusion curve approaches the simplest logistic model. At cliques of four persons, acceleration from“seeking non-knowers”offset deceleration from clique barriers.