Experiencing physical warmth affects implicit attitudes and altruistic behavior toward outgroup in females

Miyajima and Meng BMC Res Notes Experiencing physical warmth affects implicit attitudes and altruistic behavior toward outgroup in females Takeru Miyajima 1 Xianwei Meng 0 1 0 Japan Society for the Promotion of Science , Kojimachi Business Center Building, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083 , Japan 1 Graduate School of Human-Environment Studies, Kyushu University , 6-19-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 , Japan Objective: Experiencing physical warmth has been demonstrated to influence interpersonal warmth. However, the effects of this metaphorical link in an intergroup context is not clear. The current study aimed to investigate the effect of physical warmth on implicit attitudes and behavior toward outgroup members in a Japanese-Chinese intergroup context. After touching either a warm or cold cup for 3 min, the Japanese participants were required to complete the single-target implicit association test, which aimed to measure their implicit attitudes toward imagined Chinese people, and to express their willingness to participate in the experiments of a Chinese individual whom they interacted directly without compensation, aiming to measure their prosocial behavior toward a real outgroup member. Results: The results demonstrated that female participants who touched the warm (vs. cold) cup showed more positive attitudes and helping behavior toward the Chinese individual. Furthermore, the correlation between those attitudes and helping behaviors supports the effects of enhanced implicit attitudes and further suggests that experiencing physical warmth could increase prosocial response to outgroup members in real interactions. However, the male participants showed a reversed, but not statistically significant, effect of physical warmth on the implicit attitude. Embodied cognition; Physical warmth; Interpersonal warmth; Intergroup bias; Gender difference; Implicit association test; Helping behavior Introduction Research on embodied cognition has shown that perceived interpersonal warmth (e.g., attitude toward a person) can be moderated by the experience of physical warmth (e.g., touching a warm cup) [ 1 ]. Despite the possible common biological basis (e.g., the insular cortex) of and the experience-based association (from an “attachment theory” view) between physical and social warmth [ 2, 3 ], the underlying mechanisms of the metaphorical links remain unclear. Examinations on whether the metaphorical links extend beyond close or neutral others to outgroup members might provide further insights as evaluations of outgroup members are possibly related to the mentioned roots [ 4, 5 ] and the embodied reactions to ingroup and outgroup members’ behaviors (e.g., mimicry) vary greatly [ 6 ]. Breines [ 7 ] examined whether physical warmth can improve implicit attitudes toward outgroup members. European–American participants wrapped a warm or cold compress around their nondominant forearms and completed the implicit association tests (IATs). The tests assessed participants’ implicit attitudes toward African– Americans relative to European–Americans (dual-target IAT; Exp1) or implicit attitudes directly toward the two groups (single-target IAT; Exp2). The positive effect of holding a warm object was observed only on the relative evaluations (Exp1). Thus, whether experiencing physical warmth (vs. coldness) can improve implicit attitudes toward outgroup members remains unclear. Authors have discussed that the null result might be due to the lack of intergroup bias enhancement in the participants before the experiment, insufficient warmth of the object, or the evaluation power of the single-target IAT. The current study aimed to investigate the effects of physical warmth on implicit attitudes toward outgroup members by including intergroup bias enhancement and controlling environmental conditions (e.g., the warmth of the cup and indoor temperature). The experiment was conducted in a Japanese–Chinese intergroup context where intergroup conflict is salient [ 8 ]. After the Japanese participants had held warm or cold cups, their implicit attitudes toward imagined Chinese people were measured using the single-target IAT [ 9 ]. Further, their helping behaviors toward a Chinese individual were investigated to confirm the outcomes of these attitudes in a natural interactive manner. Main text Methods Participants Sixty-seven Japanese undergraduate and graduate students from Kyushu University (30 males, 37 females, Mage = 20.61, SD = 1.26) participated in the experiment for ¥1000 each (see Additional file 1). Two additional participants were excluded from the analysis due to experimental errors. Materials and procedure The experiment was conducted by two male experimenters, one Japanese and the other Chinese. To ensure that the participants could easily recognize their nationalities, the experimenters wore nametags with Japanese kanji (for the Japanese experimenter) and Chinese simplified ch (...truncated)