Rivalry at work increases unethical behavior

Rivalry at the workplace is a widespread and powerful yet largely understudied phenomenon with significant organizational implications. An international team of researchers studied the psychological underpinnings of rivalry and found that rivalry at the workplace largely depends on relationships and prior interactions between actors and results in increased unsporting behavior, use of deception, and a heightened willingness to employ unethical negotiation tactics. 

Kilduff, G., Galinksy, A., Gallo, E., & Reade, J. (2015). Whatever it takes to win: Rivalry increases unethical behavior. Academy of Management Journal, 59(5), 1508-1534.