Imagine you are about to buy a new home, and the real estate agent says, “I have some more information about the maintenance history of the house. Do you want to see it?” The question seems silly; of course you do. It’s a basic principle of economics and rational decision-making that when making a transaction or a choice, more information is better. Sometimes there isn’t enough time to learn more or the costs involved in gaining additional data don’t make it worth it. But when the information is freely available, it’s better to take it in. Or is it?

Consider the following hypotheticals:

• Assume you are newly married. Would you want to know whether your marriage will end in divorce?
• Would you want to know today when you will die?
• Would you want to know today from what cause you will die?

Not unlike the real estate example, all these facts might have practical value and inform future planning, but few people want to know. A recent study of people across eleven democracies found that only 25 percent would want to know when they will die (Reisch et al. 2021). Even more striking, in a 2017 study of German citizens asked about all three above questions, the number of people wanting to know the answers never topped 5 percent (Gigerenzer and Rocio 2017).

 

I hear you saying, “But these are hypothetical questions that can’t actually be known. What about real examples of choosing ignorance?” The classic case of what some psychologists have called deliberate ignorance comes from genetic testing for Huntington’s Disease (HD). HD is a progressive genetic disease with a very late onset—age thirty to fifty years—which means that before the genetic transmission was understood, many carriers passed the gene on to their children. Once HD begins, the body deteriorates, causing dementia, loss of bodily control, and, eventually, complete dependency and death (Yaniv et al. 2010). There is no cure.

The American folk singer Woody Guthrie succumbed to Huntington’s Disease at a time when it was poorly understood. His wife, Marjorie Guthrie, a professional dancer, became an advocate for HD families and started an organization that became the Huntington Disease Society of America (HDSA) (“HDSA History” n.d).

In 1983, just a few months after Marjorie Guthrie died, James Gusella, a researcher associated with the HDSA, found the genetic marker for HD on the short arm of chromosome 4. HD is an autosomal dominant disorder, which means that any child of an affected parent has a 50 percent chance of acquiring the gene for HD. Within ten years, a test was developed and made available to the public, but early surveys found that only a small minority of candidates for the test wanted to take it. A summary of studies of actual use of the test in eight European countries and Canada ranged from 4 percent of at-risk individuals in Germany, Austria, and Switzerland to 24 percent in The Netherlands (Tibben 2007; Yaniv et al. 2010). Overwhelmingly, people didn’t want to know. In a somewhat rambling radio interview, the singer Arlo Guthrie, Woody Guthrie’s son, made it clear he was not interested in being tested (Jimbob12404yahoo 2014).

HD is not the only case of medical testing that suffers from avoidance. Many people at risk for HIV are also reluctant to be tested. A Centers for Disease Control and Prevention report in 2016 estimated that one out of five people living with HIV were unaware of their status (Centers for Disease Control and Prevention 2016; Price et al. 2019). Similarly, it has been estimated that only 50 percent of women at risk for the BRCA1/2 genetic mutation, which is associated with a substantially increased risk of breast cancer, have been tested (Foster et al. 2004).

Part of the psychology of this type of deliberate ignorance involves the possibility of remediation. There is evidence that when no treatment has been found for a disorder or condition, the severity of the diagnosis is correlated with reluctance to be tested (Dawson et al. 2006). The more severe the disease, the less people want to know whether they have it. As one friend put it to me, “Why should I get tested? There’s nothing I can do about it.”

Spoiler Alert!

The urge to remain ignorant is not limited to the possibility of dreadful news. It can be fun not to know. Sometimes it’s all about the anticipation and surprise. Researchers Gigerenzer and Rocio (2017) found that 40 percent of their German participants would not want to know the sex of their child in advance; 60 percent would not like to know what they are getting for Christmas; 77 percent said that if they had taped a soccer game to watch later, they would not want to be told who won before viewing it (Gigerenzer and Rocio 2017).

The Motives for Not Knowing

Psychologists have identified several motivations for deliberate ignorance (Gigerenzer and Rocio 2017; Hertwig and Engel 2016). Four of the most important are:

1. Avoiding the negative emotions associated with foreknowledge of negative events, for example in the Huntington’s Disease case.
2. Maintaining suspense and surprise, as in the taped soccer game case.
3. Gaining strategic advantage. In some negotiations, it can be advantageous not to know how costly it would be for negotiations to break down. In other cases, deliberately remaining ignorant can be a strategy for avoiding responsibility (think used car salesperson). Similarly, despite the fact that gun violence is exceptionally high in the United States, for a quarter of a century Congress, led by conservative politicians, prohibited the funding of research on the topic (Stolberg 2021).
4. To achieve fairness and impartiality. This motivation explains why some musical auditions are done behind a curtain to avoid the musician’s age, race, or gender influencing the judges; why some college professors use a coding system on term papers to prevent them from knowing whose paper they are grading; and why scientists use double-blind experiments.

The last three cases are more obviously rational. We may have some moral concerns about the used car salesmen who deliberately fails to evaluate the brakes on the car, but we understand the strategy. Similarly, not everyone prefers surprise—I chose to know the sex of my children ahead of birth—but it is both rational and morally sound to hate spoilers and savor anticipation and surprise.

In general, the most ambiguous cases involve avoiding the negative emotions that might result from knowing. There is nothing wrong with avoiding unhappiness and seeking joy, but the choice to be knowledgeable or ignorant can have practical implications. In these cases, the rationality of the decision is more ambiguous.

Setting aside the emotional burden of knowing you have an incurable disease, getting tested for a genetic disorder can have health consequences for both the individual and his or her biological children. We now know without need of genetic testing that Arlo Guthrie was spared the HD gene. He is seventy-three years old and has only recently announced his retirement from touring (Rogers 2020). Nonetheless, when he was younger, before the test was available, he fathered four children. In his radio interview, Guthrie justified this decision by arguing that all life is valuable, even a short life. Of course, we now know his children are not at risk, but some people in Arlo’s position might have chosen not to have children. Furthermore, now that a test is available, having children while remaining ignorant of your genetic status carries a different moral weight. One could hardly criticize the person at risk for HD who chooses not to get tested but also avoids having biological children. Not everyone will want to carry the burden of knowing for certain that they will develop HD. But many people would judge the decision differently if, today, a person at risk for HD chose to have children without the benefit of knowing his or her genetic status. Similarly, despite the fact that there are effective treatments for HIV, engaging in risky behavior without knowing your HIV status might also be unwise. The CDC recommends that sexually active gay and bisexual men be tested every three to six months (Centers for Disease Control and Prevention 2021).

It is a fascinating psychological fact that if it were possible to find out when you will die, most people would choose not to know. Ignorance in this case might not be blissful, but for many people it would be preferable to certain knowledge. Furthermore, the choice to remain ignorant would not be entirely irrational. But scientific advances have created new and sometimes difficult dilemmas about knowledge and ignorance. For millennia, parents never knew what sex their child would be at birth and, as a result, were forced to hang on to suspense and uncertainty until the baby arrived. Today, parents have the choice to know in advance, a development that has made possible the somewhat questionable cultural phenomenon of the “gender reveal celebration”—something that only came to my attention this past September when pyrotechnics used at such an event in California set off a wildfire that eventually burned more than 20,000 acres (Morales and Waller 2020).

But, setting aside fire safety issues, medical testing has made some decisions about whether or not to remain ignorant much more consequential—both for the individual and for others. It’s easier to determine what’s rational when buying a house or a used car, but when the information available is for an untreatable medical condition, the rational path is less obvious. As a result, deliberate ignorance is a topic that is likely to keep philosophers and psychologists busy for a long time.

References

Centers for Disease Control and Prevention. 2016. Prevalence of diagnosed and undiagnosed HIV infection—United States, 2008–2012. MMWR No. 64: 657–662.

———. 2021. Getting tested (April 9). Available online at https://www.cdc.gov/hiv/basics/hiv-testing/getting-tested.html.

Dawson, Erica, Kenneth Savitsky, and David Dunning. 2006. “Don’t tell me, I don’t want to know”: Understanding people’s reluctance to obtain medical diagnostic information. Journal of Applied Social Psychology 36(3): 751–68.

Foster, C., D.G.R. Evans, R. Eeles, et al. 2004. Non-uptake of predictive genetic testing for BRCA1/2 among relatives of known carriers: Attributes, cancer worry, and barriers to testing in a multicenter clinical cohort. Genetic Testing 8(1): 23–29.

Gigerenzer, Gerd, and Garcia-Retamero Rocio. 2017. Cassandra’s regret: The psychology of not wanting to know. Psychological Review 124(2): 179–96.

HDSA history. N.d. Huntingtons Disease Society of America HDSA History. Available online at https://hdsa.org/about-hdsa/hdsa-history/.

Hertwig, Ralph, and Christoph Engel. 2016. Homo ignorans: Deliberately choosing not to know. Perspectives on Psychological Science 11(3): 359–72. Available online at https://doi.org/10.1177/1745691616635594.

Jimbob12404yahoo. 2014. Arlo Guthrie talks to Pete Fornatale about Huntington’s Disease and life. YouTube (January 14). Available online at https://www.youtube.com/watch?v=1RyeOYYa6w0.

Morales, Christina, and Allyson Waller. 2020. A gender-reveal celebration is blamed for a wildfire. It isn’t the first time. The New York Times (September 7). Available online at https://www.nytimes.com/2020/09/07/us/gender-reveal-party-wildfire.html.

Price, Devon M., Jennifer L. Howell, Amanda N. Gesselman, et al. 2019. Psychological threat avoidance as a barrier to HIV testing in gay/bisexual men. Journal of Behavioral Medicine 42(3): 534–44. Available online at https://doi.org/10.1007/s10865-018-0003-z.

Reisch, Lucia A., Cass R. Sunstein, and Micha Kaiser. 2021. What do people want to know? Information avoidance and food policy implications. Food Policy (May).

Rogers, John. 2020. “Gone fishing”: Arlo Guthrie, citing health, says he’s retired from touring. USA Today (October 24). Available online at https://www.usatoday.com/story/entertainment/celebrities/2020/10/24/arlo-guthrie-citing-health-says-hes-retired-touring/6020897002/.

Stolberg, Sheryl Gay. 2021. Can new gun violence research find a path around the political stalemate? The New York Times (March 27). Available online at https://www.nytimes.com/2021/03/27/us/politics/gun-violence-research-cdc.html.

Tibben, Aad. 2007. Predictive testing for Huntington’s Disease. Brain Research Bulletin 72(2-3 SPEC. ISS.): 165–71.

Yaniv, Ilan, Deborah Benador, and Michal Sagi. 2010. On not wanting to know and not wanting to inform others: Choices regarding predictive genetic testing. Risk, Decision and Policy 9(4): 317–36.