By Marcy Bonebright, dealnews Senior Staff Writer In a recent poll, dealnews asked its readers whether they felt obligated to tip even if they received terrible service. A surprising majority of readers answered in the affirmative — about 56% of respondents said they definitely would or sometimes would leave a tip in such a situation. Obviously, there are some guilty consciences out there! But why do we feel guilty when we stiff someone that's provided bad service? We delved deeper into the messy politics of tipping etiquette and discovered that, like everything else, it comes down to a question of nature versus nurture. Social Anxiety Makes Us Feel Guilty "The major reason people tip is to avoid social disapproval," Cornell professor and tipping expert Michael Lynn said in an interview with CNN Money. In fact, according to Lynn's research, a customer who leaves a good tip might be trying to dodge the server's envy. "Our willingness to tip regardless of service reflects a sense that the customer is in a better position financially," the article reads. Of course, leaving a tip regardless of whether it's earned could also be a way of alleviating the stress of being served by another person. As the article points out, Lynn's research has shown "that tips tend to be higher in countries where there is greater neuroticism about and intolerance of ambiguous situations." We Tip Regardless of Service Because We've Evolved That Way But perhaps there's something more fundamental behind our collective tipping impulse. According to a theory posed by Pleiotropy, a science blog, we may have evolved to tip our servers no matter what. "Evolutionarily speaking, what's the advantage of leaving a tip, and why do we have a sense of guilt when we don't tip? One explanation is that we evolved under conditions where breaking the moral codes were always punished, even if just in a minor way, when the cheater was found out." So, the theory goes, we evolved to feel guilty when we didn't tip. Therefore, when you stiff a waitress in Guymon, Oklahoma, the blog explains, "we can think rationally that there is no reason we should feel bad for ourselves when not leaving a tip, but we do so anyway, because guilt is a feeling we don't arrive at rationally, and our emotions don't know that we will never come back to Guymon and propose to that waitress." Whether it's out of a desire to combat social inequity or an innate drive to maintain status within the herd, one thing is certain: dealnews readers aren't the only ones leaving a tip when the service is terrible. Odds are, the server providing that shoddy service would leave a tip in the exact same situation. What do you think, readers? Is compulsory tipping the result of nature or nurture? Or is there some other force at work? Tell us your theories below! Related dealnews Features: Tips for Tipping Etiquette: How to Express Your Gratitude in Gratuity Cutting it Down to Size: Tips for Buying the Best Lawn Mower No One Needs to Know You Saved Money by Buying a Used Engagement Ring Follow @dealnews on Twitter for the latest roundups, price trend info, and stories. You can also sign up for an email alert for all dealnews features.