This survey showed that the values power (dominance over nature and resources) and universalism (respect for people and for nature) are related to attitudes toward genetically modified food (GMF) and organically grown food (OGF). Furthermore, these values have an influence on the centrality, commitment and ambivalence of these attitudes. Values that are positively related to an attitude influence how central this attitude is to a person. However, values that are negatively related to an attitude have a larger effect on the commitment of this attitude. No such pattern of effects was found for the relationship between ambivalence and values. These data suggest that centrality, commitment, and ambivalence are structurally different constructs that have a distinct relationship with specific values.