An Immersive Investment Game to Study Human-Robot Trust

As robots become more advanced and capable, developing trust is an important factor of human-robot interaction and cooperation. However, as multiple environmental and social factors can influence trust, it is important to develop more elaborate scenarios and methods to measure human-robot trust. A widely used measurement of trust in social science is the investment game. In this study, we propose a scaled-up, immersive, science fiction Human-Robot Interaction (HRI) scenario for intrinsic motivation on human-robot collaboration, built upon the investment game and aimed at adapting the investment game for human-robot trust. For this purpose, we utilize two Neuro-Inspired COmpanion (NICO) - robots and a projected scenery. We investigate the applicability of our space mission experiment design to measure trust and the impact of non-verbal communication. We observe a correlation of 0.43 (p=0.02) between self-assessed trust and trust measured from the game, and a positive impact of non-verbal communication on trust (p=0.0008) and robot perception for anthropomorphism (p=0.007) and animacy (p=0.00002). We conclude that our scenario is an appropriate method to measure trust in human-robot interaction and also to study how non-verbal communication influences a human’s trust in robots.

Endowment effects in the risky investment game?

The risky investment game of Gneezy and Potters (Q J Econ 112(2):631–645, 1997) has been proposed as a simple tool to measure risk aversion in applied settings, especially attractive in settings where participants may have limited education. However, this game can produce a significant endowment effect (attached to the initial position), so that analysis of the behavior in this game should not be done in the Expected Utility Theory (EUT) framework. The paper illustrates this point, by showing that risk tolerance can be much higher when the initial endowment concerns a risky lottery.

All by myself? Testing descriptive social norm-nudges to increase flood preparedness among homeowners

Nudges based on social norms (norm-nudges) can be compelling behavioral interventions compared with traditional interventions such as taxes and regulations, but they do not work in all circumstances. We tested two empirical norm-nudge frames in an online experiment on taking measures for flood preparedness with large samples of homeowners (N = 1805) in two European countries, to evaluate the possible interactions between norm-nudge effectiveness, individual characteristics, and intercultural differences. We contrasted these norm-nudge treatments with a control and norm-focusing treatment by asking respondents to express their beliefs about what other respondents would do before making a decision relevant to their own payoff. We find no evidence of a treatment effect, suggesting that our social norm-nudges do not affect flood preparedness in the context of a flood risk investment game.

The influence of perceived vocal traits on trusting behaviours in an economic game

When presented with voices, we make rapid, automatic judgements of social traits such as trustworthiness—and such judgements are highly consistent across listeners. However, it remains unclear whether voice-based first impressions actually influence behaviour towards a voice’s owner, and—if they do—whether and how they interact over time with the voice owner’s observed actions to further influence the listener’s behaviour. This study used an investment game paradigm to investigate (1) whether voices judged to differ in relevant social traits accrued different levels of investment and/or (2) whether first impressions of the voices interacted with the behaviour of their apparent owners to influence investments over time. Results show that participants were responding to their partner’s behaviour. Crucially, however, there were no effects of voice. These findings suggest that, at least under some conditions, social traits perceived from the voice alone may not influence trusting behaviours in the context of a virtual interaction.

Remembering the bad ones: Does the source memory advantage for cheaters influence our later actions positively?

Previous research has demonstrated that people remember information that is (emotionally) incongruent to their expectations, but it has left open the question if this memory enhancement has also an influence on our later actions. We investigated this question in one pilot study and two experiments. In all studies, participants first interacted with trustworthy and untrustworthy looking partners in an investment game. Facial trustworthiness was manipulated to stimulate social expectations about the behaviour of the partners. In a later second investment game, participants played against old opponents from the first game and new opponents. Overall, willingness to cooperate in the second game was influenced by the formerly behaviour of the opponent. However, facial trustworthiness affected economic decisions, too. Furthermore, we analysed source memory data that indicated no differences in memory between cheaters and cooperators. Instead, source guessing was related to cooperation: The more participants guessed that an untrustworthy looking face belonged to a cheater, the less they cooperated with untrustworthy looking opponents. Interestingly, in Experiment 2, we found a positive correlation between old-new recognition and later cooperation. In sum, the results demonstrate that memory and guessing processes can influence later decisions. However, economic decisions are also heavily affected by other social expectations like facial trustworthiness.

Cooperative optimality principals in differential games on networks

The paper describes a class of differential games on networks. The construction of cooperative optimality principles using a special type of characteristic function that takes into account the network structure of the game is investigated. The core, the Shapley value and the tau-value are used as cooperative optimality principles. The results are demonstrated on a model of a differential research investment game, where the Shapley value and the tau-value are explicitly constructed.