Introduction: Many Veterans with PTSD struggle with symptoms of social dysfunction, including isolation [1] and physical violence [2]. Current Veterans Affairs (VA) treatments effectively decrease posttraumatic stress symptoms (PTSS) [3, 4, 5, 6], but do not directly target social dysfunction. In the current study, we investigate deficits in two potential mechanisms: trust and social responsiveness. We propose to use the iterated Trust Game [7, 8]– an economic exchange task that operationalizes trust and social responsiveness– to investigate differences due to PTSS severity. We will also investigate changes after treatment using the Trust Game in a dataset of Veterans undergoing residential treatment for PTSD at a VA Medical Center. We hypothesize that those with greater PTSS severity will show deficits in trust or social responsiveness, and these deficits will assuage with PTSS improvement after treatment. Methods: We analyze a cross-sectional dataset of combat-exposed Veterans (n = 153) and a dataset undergoing residential treatment for PTSD (n = 36). PTSS are measured using the PTSD CheckList (PCL). Each Veteran plays a ten-round variant of the iterated Trust Game. Each round involves exchange between the Veteran (or “investor”) who is endowed $20 each round, and a “trustee”, in whom the investor may entrust any portion of the $20. The investment is tripled before being sent to the trustee, and the trustee may return any proportion. Trust is operationalized as investment, and social responsiveness is operationalized as the ability of the trustee’s changes in response to the investor—“trustee reciprocity”—to predict changes in the investor’s next round investment. We investigate the two potential mechanisms in the cross-sectional dataset. To determine the relationship between trust and PTSS, we regress investment onto PCL. To investigate the relationship between social responsiveness and PTSS, we regress round change in investment onto the interaction of PCL and trustee reciprocity. We next investigate the impact of treatment in the residential treatment dataset. To determine the impact of PTSS improvement on trust, we regress change in investment onto PCL score change (posttreatment–pretreatment). To determine the impact of treatment-related change on social responsiveness, we regress round change in investment onto the interaction of change in PCL (posttreatment–pretreatment), visit, and trustee reciprocity. Results: In the cross-sectional dataset, higher PTSS correlates with decrease in trust, operationalized as investment (β1 = −0.002, p = 0.003, n = 153). Increase in trustee reciprocity correlates with increase in round change in investment (β1 = −0.25, p < 0.001, n = 153), indicating Veterans were socially responsive. There was no PTSS-related variation in social responsive- ness (0 < β3 < 0.001,p = 0.5,n = 153). In the residential treatment dataset, less PTSS improvement correlated with decrease in trust after treatment (β1 = −0.006, p = 0.015, n = 36). Veterans were socially responsive (β1 = 0.39,p < 0.001,n = 36), with a decrease in responsiveness at posttreatment (β5 = −0.29,p = 0.001, n = 36) and a greater decrease posttreatment in those with less improvement in PTSS (β7 = −0.01, p = 0.02, n = 36). Conclusions: In the cross-sectional dataset, trust decreased with higher PTSS, while social responsiveness did not change with PTSS severity. This suggests that Veterans with more severe PTSS show deficits in trust, but not social responsiveness, and supports deficit trust as a mechanism for the social dysfunction observed in Veterans with PTSD. In the residential treatment dataset, both trust and social responsiveness decreased with less improvement in PTSS after treatment. This suggests that Veterans whose PTSS do not improve with treatment experience further decline in mechanisms of social functioning after discharge. In the absence of a control group, it is hard to determine whether this decline is due to symptom-related order effect, or unsuccessful treatment itself. These findings suggest decreased trust, but not social responsiveness, is a mechanism of social dysfunction observed in PTSD. Further investigation into mechanisms of social dysfunction and treatment-related change in Veterans with PTSD, the iatrogenic effects described, and the way these effects can be minimized is also necessary. These findings lend support to treatments that directly target social dysfunction in the context of treatment-resistant post- traumatic stress disorder. / National Institute of Health, 1I01RX000120, NIH-I01 2009-2010, 2013-2014, NIH-I01 2018-2019 National Institute of Health, 5I01RX002354, NIH-I01 2018-2019, 2020-2021 / Master of Science

Au cours des 150 dernières années, l'évolution de la coopération n'a cessé d'intriguer les biologistes de l'évolution. Les comportements coopératifs, qui procurent un avantage direct au bénéficiaire, ne peuvent être sélectionnés que si, pour le coopérateur, les bénéfices directs et/ou indirects dépassent le coût. De nombreuses observations chez l'Homme et chez d'autres espèces animales suggèrent que les comportements coopératifs pourraient être maintenus par la sélection sexuelle. Pourtant, ce champ de recherche est quasiment inexploré, que ce soit chez l'Homme ou chez les autres espèces sociales. Afin d'examiner le rôle potentiel de la sélection sexuelle sur les comportements coopératifs, deux modèles biologiques ont été utilisés : l'Homme et la Souris glaneuse (Mus spicilegus). Chez l'Homme, la propension à coopérer a été quantifiée dans deux populations humaines (française et sénégalaise) principalement par des méthodes empruntées à l'économie expérimentale (jeu du bien public). Chez la souris glaneuse, l'investissement individuel dans la construction collective d'un tumulus pour l'hivernage a été mesuré en captivité. Les résultats soutiennent partiellement nos prédictions, à savoir : (i) que les individus coopèrent davantage en présence de partenaires sexuels potentiels, (ii) que les coopérateurs sont préférés comme partenaires sexuels, et que (iii) ces préférences conduisent à un appariement selon la coopérativité. De plus, ils suggèrent que des traits physiques (visuels, olfactifs, ou acoustiques) puissent être utilisés pour détecter la coopérativité d'un individu. Chez l'Homme, en particulier, des traits statiques du visage, dont au moins certains sont lisibles inter-culturellement, semblent impliqués. Enfin, une éventuelle association entre les comportements coopératifs et une hormone sexuelle, la testostérone, a été examinée. Pris dans leur ensemble, nos résultats suggèrent que la sélection sexuelle pourrait être impliquée dans l'évolution et le maintien de la coopération et ouvrent donc la voie à de nouvelles recherches, examinant son influence dans diverses populations humaines, ainsi que dans de nombreuses autres espèces sociales. Mots clés : Coopération, Altruisme, Générosité, Investissement parental, Attractivité, Jeu du bien public, Choix de partenaire, Homogamie, signal de coopérativité et détection, Régulation hormonale, Testostérone. / Over the past 150 years, the evolution of cooperation has challenged evolutionary biologists. Cooperative behaviour provide a benefit to the recipient and can only be selected for if it also provides direct and/or indirect benefits to the actor that accepted the costs of the cooperative action. Many observations in humans and other animal species suggest that cooperative behaviour could be maintained by sexual selection. However, the hypothesis that sexual selection could be involved in the evolution of cooperation has not received much attention in the recent literature. In order to examine the potential role of sexual selection in cooperative behaviour, two biological models were used: humans and the Mound-building mouse (Mus spicilegus). In two human populations (French and Senegalese populations), cooperativeness was quantitatively measured, mainly by an economic game (the public good game). The spontaneous cooperativeness exhibited during collective mound-building for overwintering was assessed in captivity for Mus spicilegus. The results partly support our predictions: (i) individuals cooperativeness increase in the presence of potential sexual partners, (ii) cooperators are preferred as sexual partners, (iii) these preferences lead to assortative mating based on cooperativeness. Moreover, they suggest that physical traits (visual, olfactory, or acoustic) could be used to detect individual cooperativeness. In humans, static facial traits seem to be involved, and some of them appear to be inter-culturally readable. Finally, a potential association between cooperative behaviour and testosterone levels, a sex hormone, was examined. Together, these results suggest that sexual selection could be involved in the evolution and the maintenance of cooperation. Furthers studies are needed, in different human populations and in different social species, to further investigate the role of sexual selection in cooperative behaviour. Keywords: Cooperation, Altruism, Generosity, Parental investment, Attractiveness, Public Good Game, Mate choice, Homogamy, Detection, Signaling, Hormonal regulation, Testosterone.

Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-08-25T18:19:56Z No. of bitstreams: 1 DissGOZ.pdf: 590353 bytes, checksum: c171c33d16a9ff7a86b78b33d054b53f (MD5) / Approved for entry into archive by Ronildo Prado (bco.producao.intelectual@gmail.com) on 2018-01-25T18:45:30Z (GMT) No. of bitstreams: 1 DissGOZ.pdf: 590353 bytes, checksum: c171c33d16a9ff7a86b78b33d054b53f (MD5) / Approved for entry into archive by Ronildo Prado (bco.producao.intelectual@gmail.com) on 2018-01-25T18:45:40Z (GMT) No. of bitstreams: 1 DissGOZ.pdf: 590353 bytes, checksum: c171c33d16a9ff7a86b78b33d054b53f (MD5) / Made available in DSpace on 2018-01-25T18:48:39Z (GMT). No. of bitstreams: 1 DissGOZ.pdf: 590353 bytes, checksum: c171c33d16a9ff7a86b78b33d054b53f (MD5) Previous issue date: 2017-03-06 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Economic games are useful as experimental models of complex social interaction situations such as altruism. These games are important because they allow you to analyze the variables involved in people's decision making. However, the definition of altruism under the behavioral perspective is still imprecise, which hampers experimental control, with respect to both stimuli control, and with respect to response and reinforcement parameters. The present study sought to review the conceptual literature on the topic of altruism, seeking to elucidate the construction of this concept in Behavior Analysis and then propose an inverted model of the Sharing Game based on a conceptual refinement on the operationalization of altruism. Both the Inverted Sharing Game and the Traditional Sharing Game (Kennelly & Fantino, 2007) require participants to choose between two different amounts of money, one larger and one smaller for themselves and an anonymous participant. However, in the Sharing Game when the participant chooses the highest amount for himself, he ends up making an even bigger amount available to the other participant, and when he chooses the lowest amount of money for himself, he makes available to the other an even smaller amount. The Inverted Sharing Game, on the other hand, operates the opposite way, that is, when the participant chooses the largest amount of money for himself, provides a smaller amount to the second participant and, if he chooses the smallest amount for himself, the Another participant earns a larger amount. In a cross-subject design, experiments involving repeated attempts were made with twenty opportunities in which the participants chose how to distribute the resources between themselves and a passive participant. Two hundred participants were equally distributed under four conditions, one of which was the exposure to the Sharing Game, another to the Inverted Sharing Game, and the other two conditions were a junction between the two models presented in different orders. The experiment demonstrated that the number of self-controlled responses evoked by the Sharing Game is greater when compared to the Inverted Sharing Game, in addition to suggesting that there is an order effect of one game over the other. The study has social and scientific importance while presenting two experimental models to study the phenomenon of generosity or altruism, of particular interest in the scope of cooperation, its social importance and the survival of the species. / Jogos econômicos são úteis como modelos experimentais de situações de interação social complexa como altruísmo. Estes jogos são importantes porque permitem analisar as variáveis envolvidas na tomada de decisão das pessoas. Entretanto, a definição de altruísmo sob a perspectiva comportamental ainda é imprecisa, o que dificulta controle experimental, tanto no que diz respeito ao controle por estímulos, quanto no que se refere aos parâmetros da resposta e do reforço. O presente trabalho procurou revisar a literatura conceitual sobre o tema altruísmo, procurando elucidar a construção deste conceito na Análise do Comportamento e em seguida propor um modelo invertido do Jogo da Partilha baseado em um refinamento conceitual sobre a operacionalização do altruísmo. Tanto o Jogo da Partilha Invertido, quanto o Jogo da Partilha Tradicional (Kennelly & Fantino, 2007) exigem que os participantes escolham entre duas quantias diferentes de dinheiro, uma maior e outra menor para si mesmo e pra um participante anônimo. Entretanto, no Jogo da Partilha quando o participante escolhe a maior quantia pra si mesmo, ele acaba disponibilizando uma quantia ainda maior para o outro participante e, quando escolhe a menor quantia em dinheiro pra si disponibiliza pro outro uma quantia ainda menor. O Jogo da Partilha Invertido, por sua vez, opera da maneira oposta, isto é, quando o participante escolhe a maior quantia de dinheiro pra si mesmo, disponibiliza uma quantia menor para o segundo participante e, caso escolha a menor quantia para si, o outro participante ganha uma quantia maior. Em um delineamento entre sujeitos, foram realizados experimentos envolvendo repetidas tentativas com vinte oportunidades em que os participantes escolhiam como distribuir os recursos entre si e um participante passivo. Duzentos participantes foram igualmente distribuídos em quatro condições, sendo uma delas a exposição ao Jogo da Partilha, outra ao Jogo da Partilha Invertido, e as outras duas condições eram uma junção entre os dois modelos apresentados em diferentes ordens. O experimento demonstrou que o número de respostas autocontroladas evocadas pelo Jogo da Partilha é maior se comparado ao Jogo da Partilha Invertido, além de sugerir a existência de um efeito de ordem de um jogo sobre o outro. O estudo tem importância social e científica ao apresentar dois modelos experimentais para estudar o fenômeno da generosidade ou do altruísmo, de particular interesse no âmbito da cooperação, por sua importância social e de sobrevivência da espécie. / FAPESP: 2015/03751-2

Submitted by Daniele Amaral (daniee_ni@hotmail.com) on 2016-09-13T17:55:09Z No. of bitstreams: 1 DissFSS.pdf: 1360494 bytes, checksum: 5c89e0de122abd4765ba50babcca44a7 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-15T13:31:48Z (GMT) No. of bitstreams: 1 DissFSS.pdf: 1360494 bytes, checksum: 5c89e0de122abd4765ba50babcca44a7 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-15T13:31:56Z (GMT) No. of bitstreams: 1 DissFSS.pdf: 1360494 bytes, checksum: 5c89e0de122abd4765ba50babcca44a7 (MD5) / Made available in DSpace on 2016-09-15T13:32:03Z (GMT). No. of bitstreams: 1 DissFSS.pdf: 1360494 bytes, checksum: 5c89e0de122abd4765ba50babcca44a7 (MD5) Previous issue date: 2015-08-07 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / The Sharing Game, an economic game, studies behavior involved in resource allocation. The participant faces several trials in which he must choose between two options, both with an amount of resources for him and for other passive participant. In the optimal option the distributor receives more and the receiver even more, and in the non optimal option the distributor receives less and the other even less. From their choice, participants may be classified as optimizers, egalitarians or competitives. This work intends to assess whether and to what extent, distributions of strategies in the Sharing Game are affected by the variables gender distributor and allocation frame (gains or losses). There were the Experimental Conditions Gain-Loss and Loss-Gain, both involving hypothetical money. Data were collected online through the website Survey Monkey (n=427). In an intragroup analysis, there was no difference in the strategies adopted by participants distributing gains and losses. However, a between group analysis showed a significant order exposure effect of the allocation type, that is, if the game started with gains or losses. When comparing the two experimental conditions, the Gain-Loss condition presented an optimized strategy in a higher percentage of participants, and the Loss-Gain condition showed a higher percentage of participants both in the egalitarian and competitive strategies. Significant gender differences were found in the two experimental conditions, since in both of them the optimal strategy showed a higher percentage of men. This study has social and scientific importance by presenting an experimental model to study cooperation and competition. It also contributes for the economic games being more known and used in Psychology and Behavior Analysis. Finally, it provides greater generality to the data which may still be inconclusive regarding gender and the use of gains or losses in economic games. / O Jogo da Partilha é um jogo econômico que estuda os comportamentos envolvidos na distribuição de recursos. O participante deve escolher, em uma série de tentativas, entre duas opções com uma quantidade de recursos para ele e para outro participante passivo. Na opção ótima, o distribuidor recebe mais e o outro participante mais ainda e na opção não ótima, o distribuidor recebe menos e o outro menos ainda. A partir das escolhas dos participantes, verificam-se quantos foram otimizadores, igualitários e competitivos. Este trabalho pretendeu avaliar se, e em que extensão, as distribuições de estratégias no Jogo da Partilha são afetadas pelas variáveis gênero do distribuidor e tipo de alocação (ganho ou perda). Houve a Condição Experimental Ganho-Perda e a Condição Experimental Perda-Ganho, ambas envolvendo distribuição de dinheiro hipotético. Os dados foram coletados on-line através do site Survey Monkey (n=427). Em uma análise intragrupo, não houve diferença nas estratégias adotadas pelos participantes, entre distribuir ganho e perda. Porém, uma análise entre grupos mostrou efeitos significativos da ordem do tipo de alocação e do gênero do distribuidor. Na condição Ganho-Perda, houve uma maior porcentagem de participantes na estratégia otimizada, e na condição Perda-Ganho houve uma maior porcentagem na igualitária e na competitiva. E, nas duas condições experimentais, houve uma maior porcentagem de homens na estratégia otimizada. Este trabalho possui importância social e científica ao apresentar um modelo experimental para estudar competição e cooperação, ao contribuir para os jogos econômicos serem mais conhecidos e utilizados na Psicologia e na Análise do Comportamento, e ao fornecer maior generalidade aos dados inconclusivos em relação ao gênero e à utilização de ganho e perda em alocações de recursos. / 2012/23951-8