From the article, the study compared 48 people given free popcorn throughout the session to 48 people given one sugar cube at the beginning of the session. Those given the sugar cube demonstrated more positive responses to the advertised products.<p>The variables seem to be: (1) the substance of popcorn vs the substance of sugar cubes; (2) the quantity of stuff administered; (3) the duration over which someone got free stuff; (4) the overall caloric intake; (5) chewing vs non-chewing; (6) the degree to which the absorption times vary between sugar and popcorn.<p>Let me offer an alternative explanation: if you have nothing to do because your sugar cube dissolved and you're bored, you might pay more attention to the ads. If you're getting an unlimited supply of popcorn, that might be more entertaining to focus on than the ads.<p>At any rate, this study probably isn't testing what they think it's testing. It certainly doesn't demonstrate that the act of chewing has any causal relationship with their findings.