"Our research shows how information order can be used to create a tentative preference for one option over another," explain the researchers. "Once a leader emerges, consumers build support for it by biasing their interpretation of new information to favor it. The consequence of this process is that it is possible to dictate which brand consumers ultimately select, merely by changing the order of the information."
The researchers examined leader-driven primacy in three studies, using backpacks, winter coats, and restaurants as test subjects. In one study, two options were intentionally made to be equivalent overall. In another, one choice was markedly superior. In both studies, the researchers were able to influence which brand was favored, noting "this is the first paper to show that information order can be used to influence choice in such a way."
In the third study, the researchers explored a method to reduce the effect of leader-driven primacy: they had subjects focus more on the whole brand than on the individual features of each brand. Sure enough, these particular subjects were more objective and less influenced by early positive information about a brand.
Kurt A. Carlson, Margaret G. Meloy, and J. Edward Russo. "Leader-Driven Primacy: Using Attribute Order to Affect Consumer Choice." Journal of Consumer Research, March 2006.