This research study the effects of Corruption in Brazil, having a field experiment design in social media platform, to explain the causal relationship between two prevalent concepts throughout humankind's history, opportunism, and corruption. To measure individual believes, decision-making, and willingness to act. First, I start with a literature review and economic model; continue with the proposed experimental design, channels, mechanisms, intervention, and expected effects, suggesting future avenues for research. Then conclude that bureaucracy and incentives promote corruption, but lack of accountability perpetuates an opportunistic culture, where corruption is an acceptable social norm, thus I suggest actions for corruption no longer be a social norm in Brazil. More details of the experiment are available in the appendix, including pertinent information in the original language Portuguese.