Partner Choice Research Articles

Selfish optimization and collective learning in populations

A selfish learner seeks to maximize their own success, disregarding others. When success is measured as payoff in a game played against another learner, mutual selfishness typically fails to produce the optimal outcome for a pair of individuals. However, learners often operate in populations, and each learner may have a limited duration of interaction with any other individual. Here, we compare selfish learning in stable pairs to selfish learning with stochastic encounters in a population. We study gradient-based optimization in repeated games like the prisoner’s dilemma, which feature multiple Nash equilibria, many of which are suboptimal. We find that myopic, selfish learning, when distributed in a population via ephemeral encounters, can reverse the dynamics that occur in stable pairs. In particular, when there is flexibility in partner choice, selfish learning in large populations can produce optimal payoffs in repeated social dilemmas. This result holds for the entire population, not just for a small subset of individuals. Furthermore, as the population size grows, the timescale to reach the optimal population payoff remains finite in the number of learning steps per individual. While it is not universally true that interacting with many partners in a population improves outcomes, this form of collective learning achieves optimality for several important classes of social dilemmas. We conclude that naïve learning can be surprisingly effective in populations of individuals navigating conflicts of interest.

Why Warmth Matters More Than Competence: A New Evolutionary Approach

Multiple lines of evidence suggest that there are two major dimensions of social perception, often called warmth and competence, and that warmth is prioritized over competence in multiple types of social decision-making. Existing explanations for this prioritization argue that warmth is more consequential for an observer’s welfare than is competence. We present a new explanation for the prioritization of warmth based on humans’ evolutionary history of cooperative partner choice. We argue that the prioritization of warmth evolved because ancestral humans faced greater variance in the warmth of potential cooperative partners than in their competence but greater variance in competence over time within cooperative relationships. These each made warmth more predictive than competence of the future benefits of a relationship, but because of differences in the distributions of these traits, not because of differences in their intrinsic consequentiality. A broad, synthetic review of the anthropological literature suggests that these conditions were characteristic of the ecologies in which human social cognition evolved, and agent-based models demonstrate the plausibility of these selection pressures. We conclude with future directions for the study of preferences and the further integration of social and evolutionary psychology.

Still Invisible after All These Years? Female God-Language in the Hebrew Bible: A Response to David J. A. Clines

Abstract In a recent JBL article, David J. A. Clines reviews twenty-two Hebrew Bible texts that allegedly include female god-language. His review concludes: “There is not a single instance of female language about the deity in the Hebrew Bible.” Three major methodological difficulties undermine this unqualified conclusion: the selective choice of conversation partners, together with an inattention to the history of feminist biblical scholarship; the author’s decision to exclude metaphor theory from the scope of his article; and, finally, his paradoxical failure to define at the outset what “female” language means in reference to the deity. The article’s significant methodological deficiencies make its conclusions inevitable and, in effect, yield a literalist reading. Given the importance of the topic to the discipline, the present response provides a more hermeneutically self-aware analysis of the methodological and theoretical issues. This study demonstrates that feminist scholarship has an intellectual history essential to exegetical studies of such texts, and that metaphor theory is essential to any discussion of gendered language for the deity in the Hebrew Bible.

Institutional determinants of IJV partner choice in Europe: a host-country, a home-country or a third-country partner?

PurposeThis study aims to examine the international joint venture (IJV) partnership strategy in Europe from an institutional perspective. A firm operating in a foreign country via an IJV can partner with a local firm from the host country, a firm from the same home country or a firm from a third country. This study takes the first step in examining the determinants of these partner choices.Design/methodology/approachThis study tests hypotheses based on a data set of 637 IJVs in Europe.FindingsForeign firms are less likely to operate in a partnership with a firm from the home country or from a third country (compared to operate in a partnership with a local firm) when the host country institutions are weaker or institutional distance is larger. Also, foreign firms’ disinclination to operate in a partnership with a firm from the home/third country when the host country institutions are weaker or institutional distance is larger will diminish with greater host-country experience.Practical implicationsThis study provides important insights for firms for evaluating partner choice and potential collaborations in the European region with heterogenous institutions.Originality/valueThe partner choice among the above three forms has been neglected in the literature. This study first conceptualized that the institutional profile of the host country and institutional distance between the host country and the home country can determine the partner choice.

Who to help? Helping decisions in a cooperatively breeding bird with redirected care

Cooperative breeding sometimes occurs when adult breeders form groups following natal dispersal and mating. In such cases, individuals typically face a choice of social partner with whom to cooperate. Selecting appropriate social partners is crucial to maximising the fitness payoffs from cooperation, but our understanding of the criteria guiding partner choice is limited. Here, we analyse helping decisions by long-tailed tits (Aegithalos caudatus), which may redirect their care to assist breeders in raising offspring following the failure of their own nests. In this species, helpers prefer to help relatives at nearby nests, but it is unclear whether other criteria that may affect helper fitness also influence helping decisions. When choosing among broods of equivalent kinship, we found that helpers did not prefer those broods that offered the greatest indirect fitness returns. Further analyses revealed that helpers did not choose nests on the basis of brood size or age, but were more likely to help broods that were closer to their own failed nests and that were already being cared for by other helpers. Both effects likely reflect the limited choice available to helpers: although individuals breed close to relatives within kin neighbourhoods, a high rate of nest predation constrains helpers’ choice of broods. In other species where cooperatively breeding groups form after natal dispersal, a greater range of options may be available and here detailed analysis of group formation will be helpful for determining the decision rules that underpin partner choice and permit stable cooperation in the face of alternative options.Significance statementCooperative breeding occurs most frequently when offspring delay dispersal from their natal site and help to care for their younger siblings. In some species, however, individuals first disperse and then come together as adults to cooperate in rearing young. In the latter case, multiple social partners may be available — what then determines which partner is helped? We studied partner choice in long-tailed tits, which may help to feed other broods if their own brood fails. When multiple related broods were available, individuals were more likely to help those close by but showed no preference for broods offering the greatest indirect fitness returns. One explanation for this result is that helping options for most individuals are limited by high levels of nest predation, favouring a simpler decision-making process based on identifying close relatives breeding in close proximity.

Signaling benefits of partner choice decisions.

When deciding whom to choose for a cooperative interaction, two features of prospective partners are especially relevant: ability to provide benefits, and willingness to provide those benefits. Often, these traits are correlated. But, when ability and willingness are in conflict, people often indicate that they value willingness over ability, even when doing so results in immediate losses. Why would such behavior be favored by natural selection acting at the level of the individual? Across nine experimental studies (seven preregistered) and a mathematical model we explore one way of explaining this costly choice, demonstrating that choosing a willing over an able partner affords one a moral reputation and makes one more likely to be chosen as a cooperation partner. In fact, even people who choose an able over a willing partner for themselves prefer others who choose a willing over an able partner. Crucial to our model, we find that valuing willingness over ability is an honest signal of both higher levels of generosity in an economic game and lower levels of trait Machiavellianism. These findings provide the first extensive exploration of the signaling benefits of partner choice decisions. Furthermore, this work provides one explanation for why we choose those who are willing over those who are able, even at a cost to ourselves: By doing so, we in turn look like good potential partners. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Effect of Pre-Merger and Acquisition Capability Strategies on Value-Based Financial Performance of Banks in Ghana

Purpose – The purpose of this paper is to examine the effect of pre-merger and acquisition capability strategies on value-based corporate financial performance of banks in Ghana. Design/Methodology/Approach: A cross-sectional survey was employed comprising four (4) acquirer banks listed on Ghana Stock Exchange (hereafter GSE) and four hundred and eighty-two (482) respondents purposively selected for this study. Data were analyzed using descriptive statistics, principal component analysis (PCA) and regression analyses. All the analyses were performed using SPSS v21. Findings: The findings reinforce the important position pre-merger and acquisition capability strategies on value-based corporate financial performance of acquirer banks. Amongst the pre-M&A success capability strategies that maximise shareholder value are: strategic intent; clear criteria; choice and evaluation of strategic partner and size mismatch; financial, legal and operational due diligence; integrative approach that strengthens the core business, expands the core business and unlocks new business areas; and effective communication before acquisition). Research Limitations/Implications: The study employed only a single research methodological approach, therefore future research could be undertaken using a mixed approach and triangulate to compare findings. Furthermore, the findings from the present study are cross-sectional, considering the limitations there in, a longitudinal approach should be explored. Practical Implications: Emphasis should be place on pre-merger and acquisition capability strategies that maximise shareholder value. This will help practitioners make legitimate decisions and conclusions that can foster business growth. Originality/Value: the effect of pre-merger and acquisition capability strategies on value-based financial performance was tested; previous studies have tended to test the direct effects.

Free to choose: Mutualist motives for partner choice, proportional division, punishment, and help

Free to choose: Mutualist motives for partner choice, proportional division, punishment, and help

The Diversity of Lichenized Trentepohlioid Algal (Ulvophyceae) Communities is Driven by Fungal Taxonomy and Ecological Factors.

Trentepohliales are a group of both free-living and lichenized algae, with most diversity occurring in tropical regions. Recent studies showed that the abundance of lichens with a trentepohlioid photobiont has been increasing in temperate habitats, probably because of global warming, which makes them an interesting study case. A detailed molecular study of the diversity of lichenized Trentepohliales, epiphytic as well as epilithic, was performed in three forests of north-western Europe. Additional samples of lichens of the Arthoniales order (associating essentially with a trentepohlioid photobiont) from other European regions and from other continents were also sequenced. A total of 195 algal sequences were obtained. Phylogenetic analyses with rbcL and ITS loci were performed and associations between phylogenetic distances of photobionts and ecological factors (substratum, climate or Wirth indices, mycobiont taxonomy, and geographic location) were tested by variation partitioning and phylogenetic signal analyses. The high number of rbcL algal haplotypes found in some lichens or on different substrata revealed that the Trentepohliales diversity in extratropical regions was underestimated. The phylogenetic patterns showed selectivity of some photobionts in their fungal partner choice and vice-versa, while others were linked with several haplotypes. Photobionts seemed to be less selective than mycobionts. The main factors influencing lichenized algal community were climate and mycobiont species. Coevolution between mycobionts and photobionts as well as switching between free living and lichenized lifestyles appeared to drive the evolution of Trentepohliales and might explain the high cryptic diversity observed, which might be changing in some regions due to climate change.

Patterns and Trends of Same-Sex Partner Choice in Germany

This paper analyses the age and educational homogamy of same-sex couples in Germany over a 20-year period from 1996 to 2015. Data of the Microcensus show that cohabiting same-sex couples are less likely to be homogamous than cohabiting different-sex couples, both in terms of age and education. For same-sex couples, gender matters, male same-sex couples being the most diverse. The analyses thus confirm previous results for other European countries. Hitherto, changes in the homogamy of same-sex couples over time had not been studied in Europe, mainly due to data constraints. However, major changes in the visibility and legal acceptance of same-sex couples suggest that their patterns of partner choice are becoming more similar to those of different-sex couples. Our analyses show that the age difference among female same-sex couples has indeed narrowed over time, converging with the age difference among different-sex couples. For male same-sex couples though, there is no clear trend. In terms of educational homogamy, contrary to our assumption, we find a clear decline among same-sex couples of both genders since the 2000s, making them even more dissimilar to different-sex couples.

Free to choose: Mutualist motives for partner choice, proportional division, punishment, and help.

Mutualism–the disposition to cooperate in ways that benefit both actor and recipient–has been proposed as a key construct in the evolution of cooperation, with distinct adaptations for 1) partner choice, 2) division, 3) punishment, and 4) helping. However, no psychological validation of this 4-fold psychological structure exists, and no measure of the trait is available. To fill this need, in two pre-registered studies (total N = 902), we: (A) Develop and administer items assessing each of the four mutualist adaptations; (B) Show good fit to the predicted four factor model; (C) Demonstrate reliability and stability across time; (D) Evidence discriminant validity from existing constructs, including compassion and utilitarianism; (E) Establish external validity by predicting proportional choices in catch division, opposition to partner coercion, and reduced support for redistribution; and (F) Replicate each of these findings. Jointly, these results support the validity of mutualism, including a motive to maintain the freedom to choose, and provide reliable scales for use in integrating, further developing, and applying mutualism.

Short and long-term costs of inbreeding in the lifelong-partnership in a termite

Social life and lifelong partner commitments are expected to favor thorough partner choice, as an ill-suited partnership may have long-term consequences, adversely affecting the parents and spanning several cohorts of offspring. Here, we used ~1400 termite incipient colonies to estimate the short- and long-term costs of inbreeding upon the survival of the parents over a 15-month period, their productivity, and the resistance of their offspring toward pathogen pressure. We observed that foundation success was not influenced by the relatedness of partners, but by their levels of microbial load. We showed faster growth in inbred colonies with low levels of microbial load, revealing a potential tradeoff between pathogen defense and offspring production. Yet, inbreeding takes its toll later in colony development when offspring from incipient colonies face pathogen pressure. Although the success of a lifetime partnership is initially determined by the partner’s health, the cost of inbreeding in incipient colonies favors outbred colonies reaching maturity.

To collaborate and innovate for sustainability: Food retailers and their external partners

Firms collaborate with various organisations to address social and environmental issues. The existing literature has discussed such partnerships’ success factors and the opportunities they present, but few studies have provided an overview of the use of partnerships in the context of firms’ sustainability initiatives. This study investigated such sustainability partnerships, focusing on partnership mechanisms and choices of partners over time. Data were collected from 12 European retailers in the agri-food sector from 2014 through 2018 and analysed using content analysis methods. The analysis showed that during this period, the frequency of partnerships supporting philanthropic endeavours declined. Retailers simultaneously increased their use of partnerships to engage in sustainability-oriented innovation. They increasingly partnered with sustainability ventures while decreasing their partnerships with non-governmental organisations (NGOs). These changes in mechanism and partner choice may reflect a shift in retailers’ objectives from mainly engaging in legitimacy-oriented partnerships to exploring more participation in competence-oriented partnerships.

Assortative mixing among vaccination groups and biased estimation of reproduction numbers

Assortative mixing among vaccination groups and biased estimation of reproduction numbers

Motivations to reciprocate cooperation and punish defection are calibrated by estimates of how easily others can switch partners.

Evolutionary models of dyadic cooperation demonstrate that selection favors different strategies for reciprocity depending on opportunities to choose alternative partners. We propose that selection has favored mechanisms that estimate the extent to which others can switch partners and calibrate motivations to reciprocate and punish accordingly. These estimates should reflect default assumptions about relational mobility: the probability that individuals in one’s social world will have the opportunity to form relationships with new partners. This prior probability can be updated by cues present in the immediate situation one is facing. The resulting estimate of a partner’s outside options should serve as input to motivational systems regulating reciprocity: Higher estimates should down-regulate the use of sanctions to prevent defection by a current partner, and up-regulate efforts to attract better cooperative partners by curating one’s own reputation and monitoring that of others. We tested this hypothesis using a Trust Game with Punishment (TGP), which provides continuous measures of reciprocity, defection, and punishment in response to defection. We measured each participant’s perception of relational mobility in their real-world social ecology and experimentally varied a cue to partner switching. Moreover, the study was conducted in the US (n = 519) and Japan (n = 520): societies that are high versus low in relational mobility. Across conditions and societies, higher perceptions of relational mobility were associated with increased reciprocity and decreased punishment: i.e., those who thought that others have many opportunities to find new partners reciprocated more and punished less. The situational cue to partner switching was detected, but relational mobility in one’s real social world regulated motivations to reciprocate and punish, even in the experimental setting. The current research provides evidence that motivational systems are designed to estimate varying degrees of partner choice in one’s social ecology and regulate reciprocal behaviors accordingly.

Adoptees’ Partners’ Conjugal and Coparental Experiences and Their Attitudes Towards Adoption

Adopted adults are presented in the literature as being particularly vulnerable from a mental health and attachment perspective. This could affect their experience of romantic relationships. To our knowledge, however, no data directly concerning adoptees’ partners are currently available. We then explored their conjugal and coparenting experiences and attitude toward their partner’s adoption through semistructured interviews with 10 partners of adoptees, and submitted their responses to thematic analysis software. We then assessed their attachment, dyadic coping and coparenting using standardized scales. Results revealed highly contrasting experiences. Although the participants showed normal scores for all scales and although half of the sample did not consider their partner's adoption as risk factor, for a few participants adoption was a source of marital conflict, particularly around the issues related to the search for origins. Future research should examine dyadic issues such as the search for origins and choice of partner.

Association of traditional marital practices with contraceptive decision-making, couple communication, and method use among couples in rural Maharashtra, India

In India, traditional social practices around marriage, such as non-involvement of prospective brides in choice of partner and timing of marriage, child/early marriage, dowry and purdah, compromise women’s agency at the time of marriage and may also affect contraceptive practices in marriage. This paper examines the associations between traditional marital practices and contraceptive behaviours, including women’s control over contraceptive decision-making, couples’ communication about contraception, and ever use of contraceptives, among married women aged 18–29 years (N = 1,200) and their husbands in rural Maharashtra, India. Multivariable logistic regression was used to examine the association between these marginalising social practices and family planning behavioural outcomes, adjusting for demographic and parity confounders. Wives who were the primary decision-makers on who to marry had higher odds of ever having communicated with their husband on pregnancy prevention (AOR 1.76, 95% CI 1.16-2.68), and ever using modern contraceptives (AOR 2.19, 95% CI 1.52-3.16). Wives who were the primary decision-makers on when to marry also had higher odds of ever having used modern contraceptives (AOR 1.86, 95% CI 1.21-2.93). Women’s involvement in marital choice may facilitate couples’ engagement related to family planning, possibly via the establishment of better communication between partners.

Genital Ulcers and Multidrug Resistance

Chancroid is a sexually transmitted disease (STD) caused by the Gram-negative bacterium Haemophilus ducreyi and is characterised by necrotising genito-perineal ulcers which may be accompanied by inguinal lymphadenitis or bubo formation with possible spread to the thigh. We presented a rare case of a 23year old polytechnic undergraduate who presented to the hospital with complaints of extensive painful ulcer in her vulva for over ten (10) days. On culture of the swab from the ulcer, Haemophilus Ducreyi and E Coli sensitive to Ceftriazone, Ofloxacin and Gentamycin were isolated. Patient was treated with IV Ceftriazone for 5 days and Ciprofloxacin for 10 days with good recovery. The case highlighted the need for increased vigilance in managing genital ulcers in contemporary clinical practices and for carefulness in the choice of a sexual partner and practices among adolescents and young girls.

From Mating to Milk Access: A Review of Reproductive Vocal Communication in Mice

Vocalisations play a central role in rodent communication, especially in reproduction related behaviours. In adult mice (Mus musculus) the emission of ultrasonic vocalisations (USVs) has been observed in courtship and mating behaviour, especially by males. These have been found to have distinctive individual signatures that influence female choice of mating partner. The most recent findings show that vocal communication also has a role in parental cooperation, in that female mice communicate with male partners in ultrasonic frequencies to induce paternal behaviour. Infant vocalisations form the other important part of reproductive vocal communication. Although born deaf, neonatal mice are capable of producing vocalisations since birth. As an altricial species, successful mother-infant communication is essential for survival, and these vocalisations are important modulators of maternal behaviour. Three main types of infant vocalisations have been identified and characterised. Most research has addressed pure USVs, related to stressful situations (e.g., cold, isolation, handling, presence of unfamiliar males or predators), which usually elicit maternal search and retrieval. In addition, broad-band spectrum signals, emitted post-partum during cleaning of foetal membranes, inhibit biting and injury by adults and “wriggling calls,” emitted during suckling, release maternal behaviour (such as licking). Several variables have been identified to modulate vocalisations in mice, including individual characteristics such as strain/genotype, age, sex, and experimental factors such as pharmacological compounds and social context. In recent years, there has been a big increase in the knowledge about the characteristics of vocal communication in rodents due to recent technological advances as well as a growing interest from the neuroscience community. Vocalisation analysis has become an essential tool for phenotyping and evaluating emotional states. In this review, we will (i) provide a comprehensive summary of the current knowledge on mouse reproductive vocal communication and (ii) discuss the most recent findings in order to provide a broad overview on this topic.

Foreign partner choice in the public interest: Experience and risk in infrastructure public–private partnerships

Infrastructure public–private partnerships (PPPs) are collaborative agreements between a public sector entity and private sector firm that are designed to build and operate infrastructure projects. This study explores how public-sector entity experience and institutional concerns impact the choice of a local or foreign private sector partner. We find that the public entity’s prior infrastructure PPP experience has a U-shaped relationship with the likelihood of partnering with a foreign private sector firm. Meaning, we find that public entities with low and high levels of infrastructure PPP experience tend to partner with foreign private sector firms, whereas public entities with moderate levels of infrastructure PPP experience tend to partner with local private sector firms. Moreover, we find that financial risk associated with the infrastructure project moderates this relationship such that public entities with low or high levels of prior infrastructure PPP experience tend to partner with foreign private sector firms when the infrastructure project is highly leveraged. Our analysis of a global sample of project finance investments shows statistical support for our arguments. These findings regarding the determinants of PPP partner choice are significant given the massive investment in infrastructure development that is planned throughout the globe in the coming years.