trustworthy sources of information; at the least, their biases and values are known, and can be taken into account.
Second, when a friend or colleague adopts some energy innovation, for example, a solar water heater or the practice of car pooling, that adoption represents a vicarious experiment for the person who sees or hears about the effort and its results. Research on the diffusion of innovation demonstrates that people are more likely to adopt a new idea or technology if they can try it on a small scale without fully committing themselves to it (Rogers with Shoemaker, 1971); a friend’s experience can act as such a trial.
Third, information from close associates is salient—it stands out from the mass of available information and attracts attention. Part of this effect of salience (Taylor and Fiske, 1978) is due to people weighing information in proportion to its vividness (Nisbett et al., 1976; Borgida and Nisbett, 1977; Hamill et al., 1980). The experience of a friend or acquaintance may yield a vivid demonstration, not just a vicarious experiment, of what one might expect from adopting the innovation oneself. Impersonal data summaries, even from large numbers of cases, have been shown to have less impact than vivid face-to-face interactions and detailed case studies. Vividly presented information stands out from other information and is more likely to be noticed, remembered, and given weight in judgments (Taylor and Thompson, 1982).8 The experience of someone one knows well, combined with the opportunity to hear the experience firsthand, exerts an influence far greater than its status as additional information. This is true even if the friend’s experience is atypical.
A study by Nisbett and his colleagues offers this example (Nisbett, Borgida, Crandall, and Reed, 1976:129):
Let us suppose that you wish to buy a new car and have decided that on grounds of economy and longevity you want to purchase one of those solid, stalwart, middle-class Swedish cars—either a Volvo or a Saab. As a prudent and sensible buyer, you go to Consumer Reports, which informs you that the consensus of their experts is that the Volvo is mechanically superior, and the consensus of the readership is that the Volvo has the better repair record. Armed with this information, you decide to go and strike a bargain with the Volvo dealer before the week is out. In the interim, however, you go to a cocktail party where you announce this intention to an acquaintance. He reacts with disbelief and alarm: “A Volvo! You’ve got to be kidding. My brother-in-law had a Volvo. First, that fancy fuel injection computer thing went out. 250 bucks. Next he started having trouble with the rear end. Had to replace it. Then the transmission and the clutch. Finally sold it in three years for junk.
If the data in Consumer Reports were based on 1,000 cases, the information you received at the cocktail party has now increased the sample to 1,001 cases. But people do not respond to this event according to its logical