Trust or Check? Understanding the (Evolutionary) Dynamics of User Trust in AI Systems
Authors: Adeela Bashir, Zhao Song, Ndidi Bianca Ogbo, Nataliya Balabanova, Martin Smit, Chin-wing Leung, Paolo Bova, Manuel Chica Serrano, Dhanushka Dissanayake, Manh Hong Duong, Elias Fernandez Domingos, Nikita Huber-Kralj, Marcus Krellner, Andrew Powell, Stefan Sarkadi, Fernando P. Santos, Zia Ush Shamszaman, Chaimaa Tarzi, Paolo Turrini, Grace Ibukunoluwa Ufeoshi, Victor A. Vargas-Perez, Alessandro Di Stefano, Simon T. Powers, The Anh Han
Organizations: School Computing, Engineering and Digital Technologies, Teesside University · School of Mathematics, University of Birmingham · Informatics Institute, University of Amsterdam · Department of Computer Science, University of Warwick · Department of Computer Science and Artificial Intelligence (DECSAI) and Andalusian Research Institute DaSCI “Data Science and Computational Intelligence”, University of Granada, Spain · Machine Learning Group, Université libre de Bruxelles · AI Lab, Vrije Universiteit Brussel · University of Technology Dresden · School of Engineering and Physical Sciences, University of Lincoln · Division of Computing Science and Mathematics, University of Stirling
As the capabilities and adoption of Artificial Intelligence (AI) systems grow, trust in these AI systems is an increasingly urgent concern. Much research has focused on models of AI governance and has primarily examined incentives for safe development and effective regulation. Hence they typically represented users trust as a one-shot adoption choice rather than as a dynamic, evolving process shaped by repeated interactions. We instead model trust as the dynamic choice of reduced monitoring in a repeated, asymmetric interaction between users and AI developers, where checking developers' behaviour is costly. Using evolutionary game theory, we study how users' strategies of trust and developers' strategies of providing safe (compliant) or unsafe (non-compliant) AI co-evolve under different levels of monitoring cost and institutional regimes. We conduct the analysis on both imitation-based and learning-based perspectives, with the stochastic finite-population dynamics, the infinite-population replicator analysis and the reinforcement learning analysis. We find three robust long-run regimes: no adoption by users while developers provide unsafe AI, unsafe but widely adopted systems, and safe systems that are widely adopted. Only the last is desirable, and it arises when penalties for unsafe behaviour exceed the extra cost of safety and users can still afford to monitor at least occasionally. Our results formally support governance proposals that emphasise transparency, low-cost monitoring, and meaningful sanctions, and they show that neither regulation alone nor blind user trust is sufficient to prevent the drift towards unsafe or low-adoption outcomes.
Figures & tables
Role
Strategy
Description
Users
AllA
Always adopt the technology.
AllN
Never adopt the technology.
TFT
Initially adopt the technology and subsequently condition the action on the outcome of the previous interaction.
TUA
Play TFT until observing θT consecutive rounds of cooperation, then switch to unconditional cooperation and only monitor with probability p . If defection is observed while monitoring in this phase, revert to the original θT -thresholded TFT strategy.
DtG
Play TFT until observing θD consecutive rounds of defection, then switch to unconditional defection and only monitor with probability p . If cooperation is observed while monitoring in this phase, revert to the original θD -thresholded TFT strategy.
Creators
C
Produces a safe (compliant) technology, incurring a cost but ensuring reliability.
Table 1: Roles, actions, and behavioural interpretation in the AI regulatory ecosystem.
Parameter
Explanation
bu
Benefit a user receives when adopting a safe technology
bc
Benefit a creator receives when their technology is adopted
c
Cost of the creator for cooperating
v
Institutional punishment cost incurred by defecting creators
μ
Risk of adopting an unsafe AI, μ∈(−∞,1]
ϵ
Cost of monitoring
Table 2: Explanation of the key parameters of the models.
Figure 1: Interaction Sequences between Strategies. Each block represents an action of the user (left stack) and the developer (right stack), which can be cooperate (white) or defect (dark red). Users may also monitor the creator’s behaviour, paying a cost (symbols to the right of the stacks of TFT, TUA and DtG). The figure illustrates the differences between the conditional strategies: While TFT always observes, TUA may enter a state of trust after observing that the creator cooperated for θT subsequent rounds (in this example θT=3 ), whereas DtG may enter a state of distrust after observing θD defections. In those states, observation only happens with probability pT and pD respectively.
User Strategy
Creator strategy
C
D
User Payoff
Creator Payoff
User Payoff
Creator Payoff
AllA
bu
bc−c
μbu
bc−v
AllN
0
−c
0
0
TFT
bu−ϵ
bc−c
rμbu−ϵ
rbc−v
TUA
bu−rθTϵ+(r−θT)pTϵ
bc−c
rμbu−ϵ
rbc−v
Table 3: Payoff matrix . Each row specifies an action profile of the users, and the columns contain the user and creator payoffs for the two creator strategies C and D . See Table 1 for detailed explanation of the actions.
#
Risk-dominant transition
Condition
Creator strategy dominance
1
(AllA,C)→(AllA,D)
c>v
2
(AllN,C)→(AllN,D)
c>0
3
(TFT,C)→(TFT,D)
bc(1−r)+rc>v
4
(TUA,C)→(TUA,D)
bc(1−r)+rc>v
5
(DtG,C)→(DtG,D)
bc(1−r)+rc>v
Table 4: Risk-dominant conditions for creator and user strategies.
Figure 2: Graphical representation of the risk-dominant conditions in Table 4 . The left panel illustrates creator strategy dominance, where changes occur from cooperation (C) to defection (D) . The right panel shows user strategy dominance, highlighting sequential transitions between user strategies as the associated risk-dominant inequalities are satisfied. The numbered arrows correspond directly to the transition conditions listed in Table 4 .
Figure 3: Trust-based strategies enhance user adoption, while it declines as monitoring cost becomes expensive. The first and second columns show the stationary distributions of each state as a function of monitoring cost for scenarios without and with trust-based strategies, respectively. The third column displays the difference in user adoption levels between these two cases across varying monitoring costs. Rows from top to bottom correspond to increasing levels of institutional punishment ( v=0.1 , 0.5 , and 1 ). Parameters are set to bu=bc=4 , β=0.1 , Zu=Zc=100 , c=0.5 , μ=−0.2 , r=10 , θT=θD=3 , and pT=pD=0.25 .
Figure 4: Trust-based strategies enhance user adoption, which further increases with stronger institutional punishment. The first and second columns show the stationary distributions of each state as a function of monitoring cost for scenarios without and with trust-based strategies, respectively. The third column displays the difference in user adoption levels between these two cases across varying monitoring costs. Rows from top to bottom correspond to increasing levels of institutional punishment ( ϵ=0.1 , 0.5 , and 1 ). Parameters are set to bu=bc=4 , β=0.1 , Zu=Zc=100 , c=0.5 , μ=−0.2 , r=10 , θt=θD=3 , and pT=pD=0.25 .
Figure 5: Numerical modelling of user (top row) and creator (bottom row) cooperation rates for pT=1/4,pD=1/4 , θT=3 , θD=3 , bu=4 , bc=4 , r=10,μ=−2/10 , v=1/10,c=1/2 . The initial conditions were equal distribution of all strategies among the users and the creators.
Figure 6: Percentage of users (top row) adopting different strategies and creator (bottom row) cooperation rates across episodes for different monitoring costs. The prevalence of threshold-based trust strategies directly affects the creator cooperation rate. As monitoring costs rise, more users learn to adopt AllA in the middle of the simulation, leading to a decrease in the cooperation rate. Parameters: pT=1/4,pD=1/4 , θT=3 , θD=3 , bu=4 , bc=4 , r=10,μ=−2/10 , v=1/10,c=1/2 . For Q-learning, α=0.05 and ϵL=0.01 .
Figure 7: The converged percentage of users (top row) adopting different strategies and creator (bottom row) cooperation rates across monitoring costs for different learning parameters. The cooperation rate becomes more robust to the monitoring costs as the exploration rate increases or the learning rate decreases. Parameters: pT=0.25,pD=0.25 , θT=3 , θD=3 , bu=4 , bd=4 , r=10,μ=−2/10 , v=1/10,c=1/2 .
Table A4 : Equilibria for replicator dynamics for three strategies.
Figure A1 : Numerical modelling of user (top row) and creator (bottom row) cooperation rates for pT=1/4,pD=1/4 , θT=3 , θD=3 , bu=4 , bd=4 , r=10,μ=−2/10 , v=1/10,c=1/2 . The initial conditions were equal distribution of all strategies among the users and the creators.
Table A5 : Eigenvalues for replicator dynamics where user has three strategies.
Figure A2 : Strong Punishment enforces cooperation of creator when users benefits from adopting defective creators. The first and second columns show the stationary distributions of each state as a function of monitoring cost for scenarios without and with trust-based strategies, respectively. The third column displays the difference in user adoption levels between these two cases across varying monitoring costs. Rows from top to bottom correspond to increasing levels of institutional punishment ( v=0.1 , 0.5 , and 1 ). Parameters are set to bu=bc=4 , β=0.1 , Zu=Zc=100 , c=0.5 , μ=0.2 , r=10 , θt=θD=3 , and pT=pD=0.25 .
Figure A3 : User adoption dominates even without trust-based strategies, while creator cooperation relies on strong punishment. The first and second columns show the stationary distributions of each state as a function of institutional punishment for scenarios without and with trust-based strategies, respectively. The third column displays the difference in user adoption levels between these two cases across varying institutional punishment. Rows from top to bottom correspond to increasing levels of monitoring cost ( ϵ=0.1 , 0.5 , and 1 ). Parameters are set to bu=bc=4 , β=0.1 , Zu=Zc=100 , c=0.5 , μ=0.2 , r=10 , θt=θD=3 , and pT=pD=0.25 .
Institute of Biomedical Ethics and History of Medicine, University of Zürich, Zürich, Switzerland · SUPSI, Dalle Molle Institute for Artificial Intelligence (IDSIA), Lugano, Switzerland · ETH Zürich, Zürich, Switzerland