Evidence for the coincidence effect in environmental judgments: Why isn't it easy to correctly identify environmentally friendly food products?

Abstract

The coincidence effect--a phenomenon known in similarity research--suggests that people assign extra weight to features that 2 items have in common. The role of this effect in 2 kinds of environmental judgments about food products is investigated. Task 1 ("How environmentally friendly is a particular food product compared with a reference?") provided some evidence for the coincidence hypothesis. However, Task 2 ("How much more or less environmentally harmful is a food product compared with a standard?") showed anticoincidence. People's subjective evaluations were examined in regard to how they matched or deviated from objective measures of harmful environmental consequences related to food products. Coincidence and anticoincidence help to explain when and why subjective and objective evaluations may diverge.

Context Effects in Environmental Judgments: Assimilation and Contrast Effects in Separate and Joint Evaluation Modes1

“…In fact, this is what we found in prior studies. Tanner and Jungbluth (2003) compared people's (subjective) evaluations with (objective) estimates about the environmental friendliness of food products based on LCA (cf. Tanner & Jungbluth, 2003) and found a large discrepancy, with people often arriving at incorrect conclusions.…”

“…Participants were told that these dimensions represent the environmentally significant dimensions, according to current scientific research (cf. Jungbluth, 2000; Tanner & Jungbluth, 2003). A great deal of effort was undertaken to come up with product descriptions that represent “real” product instantiations.…”

“… Note. For any combination of two dimensions, Product A represents the environmentally “best” alternative within a set, and Product E represents the environmentally “worst” example (Jungbluth, 2000; Tanner & Jungbluth, 2003). IP = integrated production. …”

“…In prior research, we were able to show that environmental judgments are dependent on the nature of the judgment task (i.e., on the way in which consumers compare a given product with an implicit or explicit standard; Tanner & Jungbluth, 2003). Another factor that may affect environmental judgments is the way in which a particular product is presented; in other words, whether a given product is presented and evaluated separately (separate evaluation mode) or whether it is presented within a set of other product alternatives and evaluated side by side ( joint evaluation mode; e.g., Hsee, 1996).…”

“…Therefore, the research presented here is based on interdisciplinary collaboration with LCA experts (cf. Tanner & Jungbluth, 2003; Tanner, Kaiser, & Wölfing Kast, 2004; Tanner & Wölfing Kast, 2003). It makes use of results concerning actual environmental consequences that were based on LCAs of Swiss food products (Jungbluth, 2000; Jungbluth, Tietje, & Scholz, 2000).…”