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You thought your weekend was interesting? Ellen Tarr talks about Rh-negative blood and Sasquatch DNA

Susan Gerbic

March 27, 2017

Ellen Tarr is an associate professor of microbiology and immunology at Midwestern University in Glendale, AZ. She presented a Sunday talk at CSICon 2016 called “The Truth about Rh-Negative Blood Types.”

Susan Gerbic: Hello there Ellen, so good to talk to you about your presentation at CSICon this last October. I love the Sunday paper presentations; I’m always learning something new. And your presentation was definitely about a subject I knew nothing about. Can you please tell the readers more about your presentation?

Ellen Tarr: Of course! My presentation focused on trying to correct some common misconceptions about having a Rh-negative blood type. Approximately 15 percent of the world’s population is Rh-negative, and this has led to some interesting speculations. Some people think Rh-negative individuals are more evolved, or at least more distantly related to monkeys, compared to Rh-positive individuals. Based on a limited understanding of genetics, others go even further and claim that there is no natural way that the Rh-negative blood type could have evolved and therefore, some supernatural or paranormal race was involved. The “Rh-negative people are special” community generally accepts that being Rh-negative is associated with a wide variety of physical, cognitive, and personality traits. Most of these are relatively benign, but I’ve also seen claims that being Rh-negative blood makes you immune to some infections, such as HIV. This kind of information can be dangerous, and I hope both my presentation and upcoming article make convincing arguments that there is no evidence for these claims.

Photo by Karl Withakay.

Gerbic: I notice that you have written about Sasquatch DNA also? That must be interesting?

Tarr: Yes—I heard about the Ketchum paper from a colleague (Dr. Tyler Kokjohn). We were discussing the claim that she couldn’t get it published because mainstream scientists were biased and unwilling to give it a fair review. Lack of meaningful interaction with mainstream scientists is a valid concern, and I like to think of myself as open-minded, so I decided I would write a review. I attempted to make it accessible for nonscientists, and I wrote it less formally than I would for a journal. The paper was clearly not suitable for publication, and I tried to point out how the data should have been analyzed and presented for the study to be considered credible. In addition to people who are believers regardless of evidence level, I think there are a lot of people who would like Sasquatch (or something similar) to be real but are not willing to accept the evidence currently available. Hair analysis and DNA seem legitimate, but they don’t have the expertise to evaluate the work and determine if the conclusions are accurate. My hope is that I can bridge the gap a little. The review ended up being longer than I had anticipated, and Jeremy Vaeni was kind enough to post it on his Center for Bad Ideas site.

Gerbic: And tell us about Project Core and your involvement in it?

Tarr: I joined Project Core rather late. It was in the data analysis phase, so I wasn’t involved in designing the survey or collecting the data. It was an interesting project because everyone had different interests, which led to some individual commentaries in addition to the synopsis of results. There were some basic demographic, health, and phenomenon-related questions that had discrete answers, but there was also an open-ended portion where the respondent could describe an experience in their own words. While many stories fit various templates, there were some that didn’t resemble anything I had heard before, and I really struggled for an explanation. We are hoping the correlations we found will be used to generate and test hypotheses in further work. Of interest to me was that 30 percent of respondents that reported blood type were Rh-negative, which is more than we would have expected but consistent with other paranormal research. I have some hypotheses about this, but further work is needed to see if those are supported.

Gerbic: I’m always fascinated with how people found out about the skeptic community and what makes them decide that sitting in the audience isn’t enough anymore. What is your story?

Tarr: I found my way into the skeptic community in a roundabout way. I noticed that some people interested in the paranormal were looking for greater interaction with scientists and just jumped in where I thought I might be able to help, like with the review of the Ketchum paper and then with Project Core. I’m Rh-negative, so the topic has been on my radar for awhile. My dad read some things he thought were interesting, and I decided to see what had been scientifically established on the topic. Once I did the research, I wanted to publish it so others had the information. I looked around and decided a strictly academic journal would probably not get the audience I wanted, and I found the Skeptical Inquirer. It was reputable and had a broad audience, so I submitted my article in the hope it would be accepted. I then saw the information for CSICon and the Sunday session, and thought it would be a great way to report what I had learned.

Gerbic: Please tell us about some of the highlights of CSICon.

Tarr: I really enjoyed Jill Tarter’s talk. Everything I do is at such a small scale—I spend most of my time comparing protein sequences or looking through a microscope. It’s difficult for me to comprehend collecting and analyzing data on the scale that she talked about, and hearing about what they are looking for in all that data was really interesting. Elizabeth Loftus was after her, and finding out how successful they have been at planting memories was a little unsettling. I also attended the cold reading preconference workshop. Although I understood how it was done, I was not at all good at doing a cold reading myself. I’m not quitting the day job yet.

One thing the planners did right that they might not have even thought much about—the steady supply of coffee during the conference. So many conferences end the coffee after the morning break, but a caffeine-deprived attendee is not a happy attendee. It was my first visit to Las Vegas, so I really appreciated the meal package because I didn’t have to figure out where to go. This was also a great time to meet other conference attendees and talk with the speakers informally. The planners did a great job of scheduling events and making sure there was plenty to do.

I enjoyed the Tournament of Kings Dinner, and next year, it might be fun to get the rivalry going earlier so there is a lot of cheering from our sections. I don’t know how many people noticed, but there was a fire alarm that went off briefly during the show. I asked the server about it, and he said if there was a real problem they would be the first to know down there because of the horses, so he didn’t worry about an alarm unless someone confirmed it. I’m glad it was a false alarm, for the obvious reasons, but also because the headline, “Skeptics conference attendees die in fire because they doubted the fire alarm,” would not help the movement.

Susan Gerbic

Susan Gerbic's photo

Affectionately called the Wikipediatrician, Susan Gerbic is the cofounder of Monterey County Skeptics and a self-proclaimed skeptical junkie. Susan is also founder of the Guerrilla Skepticism on Wikipedia (GSoW) project. You can contact her at