J. Abeler, A. Becker, and A. Falk, Representative evidence on lying costs, Journal of Public Economics, vol.113, p.96104, 2014.

N. Ashraf, I. Bohnet, and N. Piankov, Decomposing trust and trustworthiness, 2006.

, Experimental Economics, vol.9, issue.3, 193208.

D. Balliet, Communication and cooperation in social dilemmas: A meta-analytic review, Journal of Conict Resolution, vol.54, issue.1, p.3957, 2010.

S. Baron-cohen, D. C. Bowen, R. J. Holt, C. Allison, B. Auyeung et al., The reading the mind in the eyes test: Complete absence of typical sex dierence in ?400 men and women with autism, PLoS ONE, vol.10, issue.8, p.136521, 2015.

S. Baron-cohen, S. Wheelwright, J. Hill, Y. Raste, and I. Plumb, The reading the mind in the eyes test revised version: a study with normal adults, and adults with asperger syndrome or high-functioning autism, The Journal of Child Psychology and Psychiatry and Allied Disciplines, vol.42, issue.2, p.241251, 2001.

M. Belot, V. Bhaskar, and J. Van-de-ven, Promises and cooperation: Evidence from a tv game show, Journal of Economic Behavior & Organization, vol.73, issue.3, p.396405, 2010.

M. Belot, V. Bhaskar, and J. Van-de-ven, Can observers predict trustworthiness?, Review of Economics and Statistics, vol.94, issue.1, p.246259, 2012.

J. Berg, J. Dickhaut, and K. Mccabe, Trust, reciprocity, and social history, Games and Economic Behavior, vol.10, issue.1, p.122142, 1995.

C. Bicchieri and A. Lev-on, Computer-mediated communication and cooperation in social dilemmas: an experimental analysis, Philosophy & Economics, vol.6, issue.2, p.139168, 2007.

C. Bicchieri, A. Lev-on, and A. Chavez, The medium or the message? communication relevance and richness in trust games, Synthese, vol.176, issue.1, p.125147, 2010.

O. Bochet, T. Page, and L. Putterman, Communication and punishment in voluntary contribution experiments, Journal of Economic Behavior & Organization, vol.60, issue.1, p.1126, 2006.

O. Bochet and L. Putterman, Not just babble: Opening the black box of communication in a voluntary contribution experiment, European Economic Review, vol.53, issue.3, p.309326, 2009.

I. Bohnet and B. S. Frey, The sound of silence in prisoner's dilemma and dictator games, Journal of Economic Behavior & Organization, vol.38, issue.1, p.4357, 1999.

G. E. Bolton, E. Katok, and A. Ockenfels, How eective are electronic reputation mechanisms? an experimental investigation, Management Science, vol.50, issue.11, p.15871602, 2004.

J. Bonnefon, A. Hopfensitz, and W. De-neys, The modular nature of trustworthiness detection, Journal of Experimental Psychology: General, vol.142, issue.1, p.143, 2013.

J. Bonnefon, A. Hopfensitz, and W. De-neys, Can we detect cooperators by looking at their face?, Current Directions in Psychological Science, vol.26, issue.3, p.276281, 2017.
URL : https://hal.archives-ouvertes.fr/halshs-01698391

K. S. Bouas and S. S. Komorita, Group discussion and cooperation in social dilemmas, Personality and Social Psychology Bulletin, vol.22, issue.11, p.11441150, 1996.

P. Brañas-garza, T. García-muñoz, and R. Hernán-gonzález, Cognitive eort in the beauty contest game, Journal of Economic Behavior & Organization, vol.83, issue.2, p.254260, 2012.

J. Bracht and N. Feltovich, Whatever you say, your reputation precedes you: Observation and cheap talk in the trust game, Journal of Public Economics, vol.93, issue.9, p.10361044, 2009.

J. Brosig, J. Weimann, and A. Ockenfels, The eect of communication media on cooperation, German Economic Review, vol.4, issue.2, p.217241, 2003.

N. R. Buchan, R. T. Croson, and S. Solnick, Trust and gender: An examination of behavior and beliefs in the investment game, Journal of Economic Behavior & Organization, vol.68, issue.3-4, p.476, 2008.

C. F. Camerer, Behavioral Game Theory: Experiments in Strategic Interaction, 2003.

A. C. Cameron and P. K. Trivedi, Microeconometrics: Methods and Applications, 2005.

S. Centorrino, E. Djemai, A. Hopfensitz, M. Milinski, and P. Seabright, Honest signaling in trust interactions: Smiles rated as genuine induce trust and signal higher earning opportunities, Evolution and Human Behavior, vol.36, issue.1, p.816, 2015.

G. Charness, Self-serving cheap talk: A test of aumann's conjecture, Games and Economic Behavior, vol.33, issue.2, p.177194, 2000.

G. Charness and M. Dufwenberg, Promises and partnership, Econometrica, vol.74, issue.6, p.1601, 2006.

G. Charness and M. Dufwenberg, Bare promises: An experiment, Economics Letters, vol.107, issue.2, p.281283, 2010.

G. Charness and U. Gneezy, What's in a name? anonymity and social distance in dictator and ultimatum games, Journal of Economic Behavior & Organization, vol.68, issue.1, p.2935, 2008.

J. Chen and D. Houser, Promises and lies: can observers detect deception in written messages, Experimental Economics, vol.20, issue.2, p.396419, 2017.

N. Chovil and A. J. Fridlund, Why emotionality cannot equal sociality: Reply to buck, Journal of Nonverbal Behavior, vol.15, issue.3, p.163167, 1991.

A. Cohn, T. Gesche, M. Maréchal-;-gangadharan, L. , N. Nikiforakis et al., Normative conict and the limits of self-governance in heterogeneous populations, European Economic Review, vol.100, 2017.

U. Gneezy and J. Potters, An experiment on risk taking and evaluation periods, The Quarterly Journal of Economics, vol.112, issue.2, p.631645, 1997.

A. Greif, Contract enforceability and economic institutions in early trade: The maghribi traders' coalition, The American Economic Review, vol.83, issue.3, p.525548, 1993.

B. Greiner, Subject pool recruitment procedures: organizing experiments with orsee, Journal of the Economic Science Association, vol.1, issue.1, p.114125, 2015.

N. Hanaki, N. Jacquemet, S. Luchini, and A. Zylbersztejn, Fluid intelligence and cognitive reection in a strategic environment: Evidence from dominance-solvable games, Frontiers in Psychology, vol.7, p.1188, 2016.

S. He, T. Oerman, and J. Van-de-ven, The sources of the communication gap, Management Science, vol.63, issue.9, p.28322846, 2016.

G. Heinze and M. Schemper, A solution to the problem of separation in logistic regression, Statistics in Medicine, vol.21, issue.16, p.24092419, 2002.

E. Homan, K. Mccabe, and V. L. Smith, Social distance and other-regarding behavior in dictator games, The American Economic Review, vol.86, issue.3, p.653660, 1996.

D. Houser and E. Xiao, Classication of natural language messages using a coordination game, Experimental Economics, vol.14, issue.1, p.114, 2011.

H. Ismayilov and J. Potters, Why do promises aect trustworthiness, or do they?, Experimental Economics, vol.19, issue.2, p.382393, 2016.

N. D. Johnson and A. A. Mislin, Trust games: A meta-analysis, Journal of Economic Psychology, vol.32, issue.5, p.865889, 2011.

S. Knack and P. Keefer, Does social capital have an economic payo ? a cross-country investigation, The Quarterly Journal of Economics, vol.112, issue.4, p.12511288, 1997.

S. L. Marlow, C. N. Lacerenza, and E. Salas, Communication in virtual teams: a conceptual framework and research agenda, Human Resource Management Review, vol.27, issue.4, p.589, 2017.

D. Meyerson, K. Weick, and R. Kramer, Swift trust and temporary groups, Trust in Organizations: Frontiers of Theory and Research, 1996.

R. O. Murphy, K. A. Ackermann, and M. J. Handgraaf, Measuring social value orientation, Judgment and Decision Making, vol.6, p.771781, 2011.

C. E. Naquin, T. R. Kurtzberg, and L. Y. Belkin, The ner points of lying online: E-mail versus pen and paper, Journal of Applied Psychology, vol.95, issue.2, p.387, 2010.

E. Ostrom, J. Walker, and R. Gardner, Covenants with and without a sword: Selfgovernance is possible, American Political Science Review, vol.86, issue.2, p.404417, 1992.

V. Rideout and M. B. Robb, Social media, social life: Teens reveal their experiences, 2018.

K. W. Rockmann and G. B. Northcraft, To be or not to be trusted: The inuence of media richness on defection and deception, Organizational Behavior and Human Decision Processes, vol.107, p.122, 2008.

D. Sally, Conversation and cooperation in social dilemmas: A meta-analysis of experiments from 1958 to 1992, Rationality and Society, vol.7, issue.1, p.5892, 1995.

S. Schwartz, E. Spires, and R. Young, Why do people keep their promises? a further investigation, Experimental Economics, vol.22, issue.2, p.530551, 2019.

M. Servátka, S. Tucker, and R. Vadovi£, 700709. solution -Right, anyways, it's in my best interest to play the die, because no matter what you choose, I will earn money. As for you, you're actually facing the risk of earning nothing at all. Do what you want, in any case I, do your statistics with those who will come next, I in any case it will go full, Journal of Economic Psychology, vol.32, issue.5, 2011.

, Good morning, everyone. Just to let you know that I will always roll the die in every period

, Dear player As, I encourage you to choose the option Right. I commit myself to choose the action Roll in order to maximize all earnings, in a fair way

, you didn't come here for nothing. So I advise all of you to choose the option Right, because I will choose the option

, Hello everyone, I think you have all read the instructions, you know well that there is a way allowing us to earn the maximum amount of money. Me and you, it's a matter of trust, that's why I simply invite you to choose

. So, uh, I'm a competitor. I came here to play. Uh. . . so. . . uh, I'd like to have competitors in front of me. And. . . always choose an action, and. . . I will always roll my. . . my game. That's it

.. , here, if you make that choice, you still have 5 chances out of 6 that it's a good choice. Otherwise, you can decide to stay in your comfort zone, and make sure you get the minimum. And then, if everything is. . .. if everything is a matter of luck, then maybe today you will make the right choice by trusting a stranger. That's it, uh, I think that in life sometimes you need to stick your neck out

, Uh, so trust and solidarity. If you are. . . if you trust me, I will act in solidarity. If you choose Right, I'll roll the die, we'll all be winners. So that's it, you have to take risks. And with me, there's no risk, if you go Right, I'll roll the die. That's it

, But this game is like in real life, it's a kind of trusting and not trusting. So if you're used to having. . . to trust people, well, bet on me

. So, just like me, you have one chance in two to act as a player. And you have either. . . the individual choice, therefore. . . in the image of our society, if we put ourselves forward, we gain more at the expense of the other. And the other choice, which was to put us both, so player A and player B, on the same line

, And others may have made the opposite choice. But, in any case, that's it, I'm in. . . I'm not introducing myself because we're not allowed to introduce ourselves, if I remember correctly

, Well, hello to all of you. So you have 6 choices to make, so 6 chances to win. It's sure that

, choosing Left is safety, but choosing Right can make you earn twice as much. So, it's up to you whether you're a gambler or not

, In fact, we're all here to increase our earnings, so we should help each other. So I propose you to choose the Right so that I. . . of course, I will choose Roll, so that, actually, we will have a chance of 5 out of 6 to have: you 12e more, and me 10e on top. So choose carefully, and above all think about how much you can earn

. Listen, But if one takes Right . . . I see you as associates, and as associates we can get 22e for two, 12 for you, and 10 for me. We have 25. Well, choose Right. That way, you'll make 12e and I'll make 10

, And above all, to win as much as possible. So, uh, I'm telling you, if you're a player A, uh, you might as well choose Right, and if you're a player B, you might as well choose to roll the die. That way, we'll win between 10 and 12e and. . . whereas if player A chooses Left

. Well, re envoying yourselves. I guess you've all read the instructions, and that we all care about making some money. So, I think it's better for you to choose Right, and for me to choose to roll the die. Because we have, well, we have 5 chances out of 6 that you get 12, and me only 10. I don't mind

. Well, What I wanted to tell you is: in this game, one shouldn't, one shouldn't be selsh or too "worried" because, as they say, too much thinking kills the game. One should know how to share the cake. Because, because in the end we'll all get our. . . our pack of cigarettes

, You know what the right decision to be made. And. . .. All I have to say to you is: trust, follow your heart. Okay? Thank you

, from what I've seen, you have to, uh, actually, you choose the action that is most protable for both of us, for both parties, and that will actually allow you to earn more than me. It's okay. It's okay, fact

, Good morning, everyone. So, very simple: by choosing Right, you have one chance in six to lose 5e, p.30

. Anyways, 5 out of 6 chances that you will win more than me, and I 1 out of 6 chances that I will win more than you, and you will lose. Because if it falls. . . if it falls 6, I'll win 14 and you 0. And in the other cases, you 12 and I 10

, than to take 5e / 5e. That's my option

. .. So, now, I'm starting to bug here. Actually, I have a choice between rolling and not rolling, actually. In fact, I'm already going to. . . in fact, I'm already going to roll, it's 100%. And you, you have a choice

. Basically, and then there will be. . . if I remember correctly. . . a die that will be rolled

, Well, then we've all read the rules. We all know what it's like

, All I have to say to you is that I'm going to cooperate anyway, so I'm going to roll the die because I don't really care if I win 10 or 14. So if you can win 12, it's good for everyone and everyone's happy. No, I meant it! Believe me or not, you can do whatever you want

, As, I'm player B. So I invite you all to put Right each time, since you will lose a lot if you put something else. I'll give you, I'll give you. . .. I commit myself to put Roll each time so that you can have a 1 in 5 chance of winning at least 12e. I hope I was convincing

, Hello to everyone. I have to make a speech. I don't know what to say, but. . . there are two choices. There is Left or Right. If one takes Left, we'll win 5e each. If one takes Right and I roll the die, we win. . . you win 12e and I win 10e. I don't want to make money that much

, You have two choices. There is either the wise choice or. . . a safe choice. I would advise you on the wise choice, the second one

, Good morning, everyone. Well, I'm getting into this funny speech, with my face oured and. . . besides, I'm a little sick. I almost have a runny nose to, so it's great. Mmm. . . yes, well, go ahead, be creative, go for it, or rather let me go for it and Right. That's it. What else can I say?

, Well, it's going to be very simple. So I plan to choose to roll constantly. So I hope you will do the same, so that we can get the most out of it, that is

, Hello everyone. So, in order for the roll to be taken into account and for us all have earnings, I advise you to do. . . to choose the option Left. That's it. Thank you all, p.39

H. .. Well, Well, I'm going to choose to roll, so. . . if you're a player. . . you have a 5 out of 6 chance of winning. That's it

, I'm not very good at speeches, and I didn't really prepare anything, so

, I'll tell you that if we're already here, let's have fun! Have a good day

, F Who makes a promise?

, we have provided evidence that a promise to Roll is a credible strategic signal, since it is strongly and signicantly predictive of the actual behavior