Three experiments investigating how a possible causal relationship works between vertical trust (i.e., trust in authorities) and horizontal trust (i.e., trust in others) are reported. In Experiment 1, 40 undergraduate students read and responded to several scenarios describing fictitious events in a foreign society. Based on their effects on trust, the scenarios were hypothesized to be grouped into the following four categories; positive effects on vertical trust, negative effects on vertical trust, positive effects on horizontal trust, and negative effects on horizontal trust. In different participant groups, subsequent to each scenario, participants’ levels of vertical or horizontal trust were assessed. As hypothesized, different scenarios had reliable effects on the two forms of trust. In Experiment 2, 64 undergraduates read the most effective scenarios from Experiment 1 and responded to how participants’ levels of vertical and horizontal trust were affected by the scenarios. Results supported the hypothesized causal relationship from vertical to horizontal trust when trust levels were decreased, but not when trust levels were increased. Results of Experiment 3, where another 48 undergraduates participated, verified that the strength of the causal effect of vertical trust on horizontal trust depends on whether trust is increased or decreased. In conclusion, the results from the three experiments indicate that increased vertical trust has positive effects on horizontal trust, decreased vertical trust has smaller negative effects on horizontal trust, and horizontal trust has no effects on vertical trust.