Welsh, D. T., Ordóñez, L. D., Snyder, D. G., & Christian, M. S. (2015). The slippery slope: How small ethical transgressions pave the way for larger future transgressions. Journal of Applied Psychology, 100(1), 114–127. https://doi.org/10.1037/a0036950

Many recent corporate scandals have been described as resulting from a slippery slope in which a series of small infractions gradually increased over time (e.g., McLean & Elkind, 2003). However, behavioral ethics research has rarely considered how unethical behavior unfolds over time. In this study, we draw on theories of self-regulation to examine whether individuals engage in a slippery slope of increasingly unethical behavior. First, we extend Bandura’s (1991, 1999) social-cognitive theory by demonstrating how the mechanism of moral disengagement can reduce ethicality over a series of gradually increasing indiscretions. Second, we draw from recent research connecting regulatory focus theory and behavioral ethics (Gino & Margolis, 2011) to demonstrate that inducing a prevention focus moderates this mediated relationship by reducing one’s propensity to slide down the slippery slope. We find support for the developed model across 4 multiround studies.

The authors conclude:
“Although the slippery-slope effect has often been described anecdotally by both scholars and practitioners, this research provides the first test of the effect in a controlled environment. Across four studies, our results extend social-cognitive theory by demonstrating that gradual changes can increase moral disengagement and unethical behavior over time. However, the effectiveness of a prevention focus in reducing unethical behavior suggests that there may be other important individual and contextual factors that influence one’s susceptibility to this phenomenon. Whereas behavioral ethics theory to date suggests that individuals are prone to committing small indiscretions but not blatant unethicality, this research sheds light on the process through which small instances of unethical behavior may begin to snowball into larger violations. Given the lack of research exploring unethical behavior over time, we hope that these findings will encourage research exploring the temporal nature of unethicality.”