Evidence-based medicine and patient-centered outcomes research share an assumption: Give patients and providers the information in plain language and you’ll improve their capacity for making good decisions. Not so. Research on patient and provider attitudes and social influences on decision-making suggests otherwise. Many factors besides evidence—e.g., tradition and emotion—impact health decisions. Too many options can confound rather than improve your capacity for making decisions. And the value of a decision is highly subjective. I'll present five major findings from prior and original research that challenges current paradigms. And I'll offer correctives for designing and evaluating decision aides in healthcare and other industries. If technology is prosthesis—if it extends our selves, corrects our deficits, and alters our attitudes and behaviors—then decision aides must employ flexible models of decision making. They must not only inform audiences, but also persuade them to engage.