Non-reciprocal Conditions Research Articles

Common marmosets (Callithrix jacchus) evaluate third-party social interactions of human actors but Japanese monkeys (Macaca fuscata) do not.

Reciprocity and cooperation are fundamental to human society and are observed in nonhuman primates. Primates are not only sensitive to direct reciprocity and its violation but also indirect reciprocity. Recent studies demonstrated that some primate species adjusted their behavior by observing others' interactions. Capuchin, marmoset, and squirrel monkeys avoided taking food from human actors who behaved nonreciprocally; however, no such empirical evidence among Old World monkeys is available. Here, we show that common marmosets, which are a highly prosocial species, discriminated between human actors who reciprocated in social exchanges and those who did not; however, Japanese monkeys, who are renowned for despotic social relationships, did not. In the reciprocal condition, 2 human actors exchanged food equally, whereas in the nonreciprocal condition, 1 actor (nonreciprocator) ended up with all the food and the other actor with none. The common marmosets avoided receiving food from the nonreciprocator in the nonreciprocal condition. Nevertheless, the Japanese monkeys did not show differential preferences in either condition. These results suggest a crucial role for prosocial tendencies in monkeys' responses to asymmetric exchanges and indicate that third-party social evaluations are not homologous among primates. Further comparative studies with direct comparisons will be required to explore the underlying mechanism of third-party social evaluations. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Neural bases of the adaptive mechanisms associated with reciprocal partner choice

In our society, partner choice is often reciprocal and, therefore, compromising one's choice may be adaptive depending on one's own market price. To reveal the neural mechanisms underlying this adaptive process, functional magnetic resonance imaging (fMRI) was performed on 27 male subjects during virtual partner choice tasks involving a dance-partner choice or a part-time job choice. Following the evaluation of a rival, the subjects chose a partner either in the face of competition with a rival (reciprocal choice condition) or during no competition (nonreciprocal condition). Irrespective of the type of partner choice situation, the posterior cingulate cortex (PCC) and right temporoparietal junction (TPJ) were specifically activated during reciprocal partner choice. The PCC was also activated during the evaluation of a rival relative to the self, which indicates the involvement of this region in the processing of one's own market price. Activation in the right TPJ was related to the individual tendency to avoid choosing a higher-value candidate when the rival-value was high in the reciprocal choice condition, which indicates that this region plays a role in market-adaptive strategy. Taken together with extant anatomical knowledge, the two-component neurobiological structure underlying the adaptive mechanism of partner choice identified in this study seems to represent the hierarchical evolution of the human socio-cognitive system.

Five-Year-Old Preschoolers' Sharing is Influenced by Anticipated Reciprocation.

Whether children share in anticipation of future benefits returned by a partner is an interesting question. In this study, 5-year-old children and an adult partner played a sharing game, in which children donated first and the partner donated afterward. In Experiment 1, the partner’s resources were more attractive than the child’s. In the reciprocal condition, the child was told that s/he would be a recipient when the partner played as a donor. In the non-reciprocal condition, however, the child was told that an anonymous child would be the recipient when the partner donated. Results showed that children shared more with the partner when they knew that they would be a recipient later. In Experiment 2, the child was always the recipient when the partner donated, but the partner’s resources were more desirable than the child’s in the high-value condition, and less desirable in the low-value condition. We found that children were more generous when the partner’s resources were valued higher. These findings demonstrate that 5-year-old preschoolers’ sharing choices take into account the anticipated reciprocity of the recipient, suggesting either self-interested tactical sharing or direct reciprocity in advance of receiving. Specifically, they adjust their sharing behavior depending on whether a partner has the potential to reciprocate, and whether it is worth sharing relative to the value of the payback.

Indifference of marmosets with prenatal valproate exposure to third-party non-reciprocal interactions with otherwise avoided non-reciprocal individuals

Autism is characterized by deficits in social interaction and social recognition. Although animal models of autism have demonstrated that model animals engage less in social interaction or attend less to conspecifics than control animals, no animal model has yet replicated the deficit in recognition of complex social interaction as is seen in humans with autism. Here, we show that marmosets discriminated between human actors who reciprocated in social exchanges and those who did not; however, marmosets with foetal exposure to valproic acid (VPA marmosets) did not. In the reciprocal condition, two actors exchanged food equally, while in the non-reciprocal condition, one actor (non-reciprocator) ended up with all food and the other actor with none. After observing these exchanges, the control marmosets avoided receiving food from the non-reciprocator in the non-reciprocal condition. However, the VPA marmosets did not show differential preferences in either condition, suggesting that the VPA marmosets did not discriminate between reciprocal and non-reciprocal interactions. These results indicate that normal marmosets can evaluate social interaction between third-parties, while the VPA marmosets are unable to recognize whether an individual is being reciprocal or not. This test battery can serve as a useful tool to qualify primate models of autism.

TRANSFER OPERATOR THEORY AND INTER-RECIPROCITY OF NON-RECIPROCAL MULTIPORT ANTENNAS

The present article expounds a formalism for the representation of multi-port non-reciprocal antenna structures in an arbitrary surrounding linear medium. In the most general approach the antenna, the waveguides connected to it, as well as the surrounding medium may contain any distribution of anisotropic magneto-electric media. Furthermore, an arbitrary external fleld is taken into consideration which need not be of plane wave form. A reciprocally adjoint system is introduced to derive relations which describe the antenna under such general conditions. Since the antenna may contain media which prohibit the use of ordinary scattering, admittance or impedance matrices, an approach by means of generalized scattering matrices, or by a generalized admittance and a generalized impedance matrix, is applied. This leads to an n-port description of the whole waveguide-antenna-environment where transfer operators render the interaction between the external fleld and the state of the ports. These operators are the generalizations of efiective length vectors. For its importance the case of reciprocal re∞ection-symmetric waveguides is treated in detail, including a derivation of the consequences of abstract network reciprocity and complex power relation for voltage-current representations. The formalism is adequate for the description of radar and radio astronomy antennas, in particular when wave polarization plays a crucial role and/or a magnetized plasma environment is present (which is responsible for anisotropy and non-reciprocal conditions).

Facilitation of quadriceps activation is impaired following eccentric exercise

Contracting the knee flexor muscles immediately before a maximum voluntary contraction (MVC) of knee extension increases the maximal force that the extensor muscles can exert. It is hypothesized that this phenomenon can be impaired by muscle fiber damage following eccentric exercise [delayed onset muscle soreness (DOMS)]. This study investigates the effect of eccentric exercise and DOMS on knee extension MVC immediately following a reciprocal-resisted knee flexion contraction. Electromyography (EMG) was recorded from the knee extensors and flexors of 12 healthy men during knee extension MVCs performed in a reciprocal (maximal knee extension preceded by resisted knee flexion), and nonreciprocal condition (preceded by relaxation of the knee flexors). At baseline, knee extension MVC force was greater during the reciprocal condition (P < 0.001), whereas immediately after, 24 and 48 h after eccentric exercise, the MVC force was not different between conditions. Similarly, at baseline, the EMG amplitude of the quadriceps during the MVC was larger for the reciprocal condition (P < 0.001). However, immediately after, 24 and 48 h postexercise the EMG amplitude was similar between conditions. In conclusion, eccentric exercise abolished the facilitation of force production for the knee extensors, which normally occurs when maximum knee extension is preceded by activation of the knee flexors.

Codependency: An interpersonal phenomenon

An alternative perspective to the clinical model of codependency is that codependency is contextual and reflects inequality within a relationship. This study examined whether the evaluation of codependent behavior depends on the context of the relationship, i.e., the reciprocity of the person’s partner, and the gender of the stimulus person (SP). College students (N=302, 46% non-Caucasian) read one of six scenarios in which the codependent SP’s behavior was held constant but the reciprocity of the partner and the gender of the SP were varied. The stimulus person and her/his relationship were rated significantly more healthy in the reciprocal condition than in the nonreciprocal or control conditions, but a better partner in the nonreciprocal condition. Codependent female SPs were judged less healthy but better partners than codependent male SPs. Judgments of codependent behavior and persons are contextual in nature, may reflect inequality within relationships, and to some extent, depend upon the gender of the codependent person.

THE EFFECT OF A RECIPROCAL DECISION RULE ON DECISIONS FOR ANOTHER PERSON1

ABSTRACTSubjects made decisions on a gambling task where the outcome would affect their own payoff or the payoff of another person. For the latter, decisions were made reciprocally or nonreciprocally, and for a friend or a stranger. Decisions for others were significantly more cautious when the subject believed that the other person was making reciprocal choices which would affect the subject's payoff than where no reciprocity was involved. Degree of friendship with the other person had no effect on the level of caution chosen for him. Subjects deciding for self more closely resembled subjects in the nonreciprocal than in the reciprocal condition in terms of chosen risk levels, but overall differences were of relatively small magnitude. The enhanced caution in the reciprocal relative to nonreciprocal condition was attributed to a desire to insure at least a modest payoff for another who might benefit the self. It is conjectured that caution in such circumstances serves the function of guilt avoidance.