Present but invisible: Physical obscurity fosters social disconnection

Research suggests that we feel invisible and disconnected when others avoid our gaze. In three studies, we examine whether similar feelings may arise when others are unable to meet our gaze—when they are unaware of our presence altogether. We posit that feelings of loneliness and disconnection can arise when others are unable to sense one's physical presence. To test whether invisibility engenders loneliness, we primed participants with the invisibility construct (Studies 1 and 2) and manipulated actual visibility (Study 3) prior to assessing feelings of loneliness and isolation. Results revealed that being present, but unseen, is sufficient to induce loneliness. Findings are related to the ostracism and intersectional invisibility literatures, and the social costs of physical obscurity are discussed.     

Effects of post-session wheel running on within-session changes in operant responding

This study tested the effects of post-session wheel running on within-session changes in operant responding. Lever-pressing by six rats was reinforced by a food pellet under a continuous reinforcement (CRF) schedule in 30-min sessions. Two different flavored food pellets were used as reinforcers. In the wheel conditions, 30-min operant-sessions with one of the flavored pellets were followed by 30-min free-wheel running sessions. Meanwhile, in the home conditions, rats’ operant responding was reinforced by the other flavored pellets during 30-min operant-sessions, and the rats were then returned to their homecages. All rats were exposed to 4 wheel and 4 homecage sessions. Operant responding was lowered during the wheel conditions. However, post-session running did not alter the within-session pattern of operant responding. These effects were practically identical to the effects of drug-induced taste-aversion learning on within-session changes in operant responding, suggesting similar mechanisms in both taste-aversion preparations.     

Humans (Homo sapiens) fail to show an inequity effect in an “up-linkage” analog of the monkey inequity test

Brosnan and de Waal (Nature 425:297–299, 2003) claimed that if a capuchin sees another capuchin receiving a superior food, she tends to reject an inferior, previously acceptable food. They related this phenomenon to human inequity aversion. This phyletic extension is “down linkage,” because nonhuman research is interpreted in terms of human research. The present experiment makes an “up-linkage” test of this claimed connection by attempting to reproduce the capuchin-inequity effect in humans. In Experiment 1’s equity condition, a subject and an adjacent confederate each clicked a computer mouse to mark the number “7” from a random numbers table, earning 0.5 yen per mark. In the inequity condition, the confederate’s pay rate was twice that of the subject. There was no between-condition difference in quitting times or likelihoods. Experiment 2 replicated Experiment 1 except, before beginning, the subject and confederate clicked a mouse over a rapidly switching message that said they would earn either 0.5 or 1 yen per marked seven. For the equity condition in this rigged test, subject and confederate stopped the message at 0.5 yen, while in the inequity condition, these values were 0.5 and 1 yen, respectively. Now, inequity-condition subjects quit sooner than equity-condition subjects. Experiment 1 found no inequity effect, but Experiment 2 did. These results show that: (a) a sense of control/responsibility may be critical to an inequity effect and (b) the inequity effect putatively present in capuchins cannot be reproduced in an up-linkage human analog of that research, thereby calling this linkage into question. This report exemplifies that up- and down-linkage tests are often requisite to establish commonality of psychological process between nonhuman primates and humans.     

Reference-dependent expected utility with incomplete preferences

An important reason why people deviate from expected utility is reference-dependence of preferences, implying loss aversion. Bleichrodt [Bleichrodt H. (2007). Reference-dependent utility with shifting reference points and incomplete preferences. Journal of Mathematical Psychology, 51, 266-276] argued that in the empirically realistic case where the reference point is always an element of the decision maker’s opportunity set, reference-dependent preferences have to be taken as incomplete. This incompleteness is a consequence of reference-dependence and is different in nature from the type of incompleteness usually considered in the literature. It cannot be handled by existing characterizations of reference-dependence, which all assume complete preferences. This paper presents new preference foundations that extend reference-dependent expected utility to cover this case of incompleteness caused by reference-dependence. The paper uses intuitive axioms that are easy to test. Two special cases of reference-dependent expected utility are also characterized: one model in which utility is decomposed into a normative and a psychological component and one model in which loss aversion is constant. The latter model has been frequently used in empirical research on reference-dependence.     

Take it or leave it for something better? Responses to fair offers in ultimatum bargaining

We investigated if responders accept a 50–50 split in a modified version of the ultimatum game, in which rejection yields a higher payoff (€7) than accepting the equal offer (€5). Therefore, the decision to accept the 50–50 split in this modified ultimatum game cannot be perceived as a self-interest act, as opposed to the standard game, in which acceptance may reflect resignation in the knowledge that the equal split is the best one can expect. A substantial proportion of responders accepts the equal split in this modified game (Study 1), which clearly establishes egalitarian preferences. Further studies show that the willingness to accept is not an artifact of indifference towards the extra payoff (Study 2), but reflects true concerns for proposers’ outcomes (Study 3).     

Does betrayal aversion really guide trust decisions towards strangers?

Trust is a double-edged sword. When warranted, it leads to positive and rewarding interactions. When not, it leads to disappointment and anger. Therefore, it has been argued that people will display “betrayal aversion” in trust situations (i.e., avoid trusting to avoid betrayal). Yet, people also feel tense and uneasy when they signal distrust to another person and thus show signs of “principled trustfulness” (i.e., choosing to trust others although being skeptical of their trustworthiness). These two theoretical orientations imply directly opposite influences on trust behavior. Thus, we conducted two laboratory studies (with a total of 841 participants) with binary trust games (implying a risk of being betrayed) and extended lottery games (implying no such risk). In both studies, we varied the payoff structures of both games. Further, we made sure that the average perceived likelihood of winning or losing money when choosing the risky option was identical in both games, as was the distribution of these likelihoods. Neither study showed any sign of betrayal aversion. Rather, participants were more willing to risk their money in the trust game than they were to invest their money in a lottery, supporting the principled trustfulness view. We discuss possible explanations why, unlike previous studies, we did not find any indication of betrayal aversion.     

The Aggregated Extremes Effect: Not All Routes to “Balanced” Bundles are Equally Appealing

Prior research establishes that consumers are averse to extreme options, but what does a “moderate” option look like in the context of choices among bundles of items, such as investment portfolios or product assortment packs? We propose that for bundles, two paths to creating risk and reward balance exist: a “bundle‐of‐pure‐moderation” with all moderate‐risk–moderate‐reward (moderate RR) components and a “bundle‐of‐extremes,” composed of equal numbers of extreme high‐risk–high‐reward (high RR) and low‐risk–low‐reward (low RR) components. We show that consumers have stronger preference for the balanced bundle when composed of a bundle‐of‐extremes rather than a bundle‐of‐pure‐moderation, even when equated on expected value, a phenomenon we term “the aggregated extremes effect.” This effect occurs across different choice set configurations and across multiple domains. Additionally, this effect is eliminated among consumers who view the high RR and low RR components as incompatible, as this undermines the perceived attractiveness of the bundle‐of‐extremes. Finally, this effect is also eliminated by exposing consumers to a depiction of potential outcomes, such that consumers can better perceive the risk reduction upside of a bundle‐of‐pure‐moderation.     

味觉厌恶性条件反射建立后脑内c-Fos的表达

以新异味觉刺激糖精水的摄入为条件刺激,以腹腔注射环磷酰胺(CY,免疫抑制剂)或氯化锂(LiCl)为非条件刺激,分别使大鼠建立味觉厌恶性条件反射.在条件刺激日,糖精水在学习组大鼠下列脑区中诱发出密集的Fos表达下丘脑、杏仁核、边缘皮质等,而非学习组在这些区域中却没有或只有少量表达.另外,在丘脑前背侧核、扣带回、下丘脑外侧核、穹隆下器、压部后颗粒皮质、视上核,CY组的Fos表达明显多于LiCl组;而在伏核、杏仁基底外侧核、腹外侧隔核,LiCl组的Fos表达明显多于CY组,这种差异可能是两种药物的不同药理性质所致.     

Enhancement of food aversion by exposure to a poisoned conspecific in Norway rats (Rattus norvegicus)

Two experiments were conducted to determine whether exposure to a poisoned conspecific enhances prior food aversion in rats. In Experiment 1, subjects were serially exposed to two foods, cocoa‐flavored and cinnamon‐flavored ones, and were then poisoned 1 h later. On the next day, they were exposed to a poisoned conspecific that had eaten a cocoa‐flavored food. On the subsequent choice test, subjects had an enhanced aversion to cocoa‐flavored food. The result was replicated in Experiment 2, in which a cinnamon‐flavored food was assigned as a target. The results are discussed in relation to previous findings.