Julie Downs-Social and Decision Sciences - Carnegie Mellon University

Julie Downs

Associate Research Professor, Social and Decision Sciences

Office: PH 219C
Phone: (412) 268-1862
Fax: (412) 268-6938


Ph.D.: Princeton University


I am interested in how social influences affect decision-making, and how people can make better decisions by understanding the nature of these influences. Many people expect to contend with direct forms of influence, such as peer pressure, but far more ubiquitous and powerful are indirect influences. These include normative group influences (doing what is expected of you according to your group status or group norms), expectancy effects (behaving in accordance with what you expect, such as with alcohol use), and lack of awareness of decision opportunities.

One goal of this type of research is to implement interventions aimed at helping people make better decisions in the face of often unseen social influences. In previous research on sexual decision-making among adolescent girls, my colleagues and I developed an interactive video DVD intervention. In a randomized clinical trial of the intervention's effectiveness among 300 sexually active adolescent girls, we found that girls assigned to view the DVD were more likely to become abstinent and, among those who continued to have sex, were less likely to have a condom fail from incorrect usage. Girls who watched the DVD were less likely to report having contracted an STD than girls who had not seen the DVD. Preliminary evidence suggests that these behavior changes may produce a reduction in acquisition of Chlamydia, the most common reportable disease in the US.

In other work, I am exploring how technology can accentuate daily risks, and how it can be used to facilitate decision making, especially in realms where available information is too complex to be used intuitively. Both of these lines of work focus on how people interpret information within different contexts, and how expectations and knowledge of the domain affects their interactions. For example, computer users are more at risk of deception by fraudulent emails if they apply strategies that work in the real world, such as relying on trust in a company. However, overall suspicion of email is not protective, as it leads to many false alarms to legitimate messages, thus undermining the benefits of this common tool. This research is informing education strategies for both email users but especially for computer programmers, to develop tools that can alert email readers about risks by using intuitive cues that are consistent with real-world decisions.


Downs, J. S., Bruine de Bruin, W. & Fischhoff, B. (2008). Parents' vaccination comprehension and decisions. Vaccine, 26, 1595-1607.

Downs, J. S., Holbrook, M. B. & Cranor, L. F. (2007). Behavioral response to phishing risk. ACM International Conference Proceeding Series, 269, 37-44

Downs, J. S., Bruine de Bruin, W., Fischhoff, B., Hesse, B. & Maibach, E. (in press). How people think about cancer: A mental models approach. In O'Hair D (Ed.) Handbook of Risk and Crisis Communication, Mahwah, NJ: Erlbaum.

Downs, J. S., Holbrook, M. B. & Cranor, L. F. (2006). Decision strategies and susceptibility to phishing. ACM International Conference Proceeding Series. 149, 79-90.

Downs, J. S., Bruine de Bruin, W., Murray, P. J., & Fischhoff, B. (2006). Specific STI Knowledge May Be Acquired Too Late. Journal of Adolescent Health, 38, 65-67.

Downs, J. S., Murray, P. J., Bruine de Bruin, W., Penrose, J., Palmgren, C., & Fischhoff, B., (2004). Interactive Video behavioral intervention to reduce adolescent females' STD risk: A randomized controlled trial. Social Science & Medicine, 59, 1561-72.

Downs, J. S., Bruine de Bruin, W., Murray, P. J., & Fischhoff, B. (2004). When 'it only takes once' fails: perceived infertility predicts condom use and STI acquisition. Journal of Pediatric and Adolescent Gynecology, 17, 224.

Ness, R.B., Hillier, S.L., Richter. H,E,, Soper, D.E., Stamm, C., Bass, D.C., Sweet, R.L., Rice, P., Downs, J., Aral, S. (2003). Why women douche and why they may or may not stop. Sexually Transmitted Diseases, 30, 71-74.

Downs, J. S. & Shafir, E. (1999). Why some are perceived as more confident and more insecure, more reckless and more cautious, more trusting and more suspicious, than others: Enriched and impoverished options in social judgment. Psychonomic Bulletin & Review, 6, 598-610.

Fischhoff, B., & Downs, J. S. (1998). Communicating Foodborne Disease Risk. Emerging Infectious Disease, 3, 489-495.

Fischhoff, B., & Downs, J. S. (1997). Accentuate the relevant. Psychological Science, 8, 154-158.