In explaining differences between groups, people ascribe the human essence to their ingroup and consider outgroups as less human. This phenomenon, called infra-humanization, occurs outside people's awareness. Because secondary emotions (e.g. love, hope, contempt, resentment) are considered uniquely human emotions, people not only attribute more secondary emotions to their ingroup than to outgroups, but are reluctant to associate these emotions with outgroups. Moreover, people behave less cooperatively (in terms of altruism, imitation, and approach) with an outgroup member who expresses himself through secondary emotions. Infra-humanization occurs for high and low status groups, even in the absence of conflict between groups. It does not occur when the outgroup target is adequately individualized, by a complete name or through perspective taking, for instance.

People attribute more secondary emotions to their ingroup than to outgroups. This effect is interpreted in terms of infrahumanization theory. Familiarity also could explain this differential attribution because secondary emotions are thought to be less visible and intense than primary ones. This alternative explanation to infrahumanization was tested in three studies. In Study 1, participants attributed, in a between-participants design, primary and secondary emotions to themselves, to their ingroup, or to an outgroup. In Study 2, participants answered for themselves and their ingroup or for themselves and an outgroup. In Study 3, participants made attributions to the ingroup or a series of outgroups varying in terms of familiarity. The data do not support an explanation in terms of familiarity. The discussion centers on conditions not conducting to infrahumanization.

People tend to infra-humanize by attributing more human essence to their in-group than to out-groups. In the present article, we focus on the attribution of primary and secondary emotions to operationalize the human essence. We propose that, in order to infra-humanize, people need to be categorized in meaningful groups. In addition, we argue that what differentiates meaningful from nonmeaningful groups is that the people essentialize, perceiving members of the group as sharing an underlying, common essence. Also, we hypothesize that participants will identify more with their in-group in the case of meaningful groups. Three types of groups were created to manipulate the meaningfulness of the categorization. Participants were either randomly assigned to a group or they chose their group as a function of their preferences for a colour or the type of career they wished to pursue. As expected, infra-humanization occurred only where the categorization's criterion was meaningful. In addition, in-group identification, but not essentialism, mediated the impact of the categorization criteria on the tendency to infra-humanize. Data also showed that infra-humanization is different from classic in-group favouritism. This is because in-group favouritism, but not infra-humanization, was observed in the situation where group membership was based on random assignment. In other words, for infra-humanization to occur mere categorization is not enough; meaningfulness is also needed. For in-group favouritism to arise, the knowledge of being part of a group is a sufficient prerequisite. The discussion focuses on conditions for reducing infra-humanization and on the relationship between in-group favouritism and out-group derogation.

This research tested the infra-humanization hypothesis that uniquely human emotions (e.g., love, sorrow) are automatically more linked in memory with the in-group than with the out-group. No such difference is expected for non-uniquely human emotions (e.g., joy, sadness) which pertain to everybody, including animals. Two studies using semantic primes followed by visual person categorization task (PCT) and lexical (lexical decision task, LDT) targets were conducted. Results supported infrahumanization theory. Reaction times were faster for the in-group/secondary emotions associations than for out-group/secondary emotions ones. As predicted, no difference in latency times appeared for primary emotions as a function of the groups. These findings elucidate the ambiguity present in Paladino et al. (2002). Theoretical and practical implications are suggested.

In line with the psychological essentialism perspective, Leyens et al. (2000) have hypothesized that people attribute different essences to groups and that they attribute more uniquely human characteristics to their own group than to out‐groups. Leyens et al. have focused on two types of emotions, which in Roman languages have specific labels, such as sentimientos and emociones in Spanish. A cross‐cultural study showed that sentimientos (or secondary emotions) are considered uniquely human emotions whereas emociones (or primary emotions) are perceived as nonuniquely human emotions. The present study focuses on whether this categorization into primary and secondary emotions is a spontaneous distinction that people use in their everyday lives, or whether, on the contrary, it is the result of experimental demands. The paradigm “Who says what to whom” was used to test this question. Geometrical shapes of different colours were systematically associated with different stimuli that varied in meaningfulness. In a first condition, shapes were associated with small or large items of furniture (meaningful categories) and with primary and secondary emotions. In a second condition, the items of furniture were replaced by words ending with a vowel or a consonant (meaningless categories). Subsequently, participants had to recognize which shape was associated with each stimulus. Intra‐category errors were significantly more numerous than inter‐category errors, except for the words ending with a vowel or a consonant. Stated otherwise, types of emotions were recognized like the meaningful difference between items of furniture. These results show that the distinction between primary and secondary emotions is an implicit one that people use spontaneously, and not as a result of task demands. The findings are discussed from the perspective of psychological essentialism and inter‐group relations.