The Human Biases Behind Nuclear Decisions

Most of us think of cognitive biases as quirks of everyday decision-making, but a recent Texas National Security Review study shows they are deeply embedded in people’s attitudes toward nuclear weapons and war.

As a student of psychology and government with a passion for nuclear risk reduction, I found the study especially compelling because it connects the two fields in a high-stakes context.

The study examines how innate biases shape public attitudes toward nuclear weapons and nuclear war. It explores how people evaluate risk, human life, and difficult trade-offs in high-stakes situations. Two findings were particularly demonstrative of the fact that psychology and nuclear policy are extensively intertwined: the extent to which cognitive biases can influence attitudes about nuclear weapons use and the possibility that the long-standing nuclear taboo may be weakening over time.

No Decisionmaker Is Immune to Biases 

One of the study’s central findings is that cognitive biases that influence everyday decisions do not disappear when people consider issues of war and nuclear weapons.

Researchers surveyed nearly 3,000 Americans and presented them with a hypothetical scenario in which the United States was engaged in a ground war with Iran. Across several survey conditions, participants were asked whether the United States should continue the conventional war that would cost, depending on the treatment condition, 100 to 40,000 American lives (expected U.S. casualties varied by condition), use a nuclear weapon that could kill 100,000 Iranians, or in separate conditions, use a nuclear weapon that could kill 2 million Iranians. Across all conditions, the most common choice was for respondents to select the option involving 100,000 Iranian casualties. In other words, many participants viewed a nuclear strike as acceptable if it prevented the deaths of a smaller number of Americans, even if those American deaths were expected to be very low relative to the number of Iranian deaths the strike would cause.

The study suggests that this outcome can be explained in part by in-group bias, or the tendency to place greater value on members of one’s own group. American respondents generally placed greater weight on American lives than Iranian lives when evaluating the scenario. The findings also reflect what psychologists call psychic numbing, the tendency to perceive large-scale suffering as statistics rather than individual human lives.

This highlights that human judgment remains vulnerable to bias even when the stakes are extraordinarily high.

In the United States, the president ultimately holds the authority to authorize the use of nuclear weapons. This underscores an important reality: decisions about nuclear weapons are not made by perfectly rational actors but by people influenced by emotions, cognitive shortcuts, and biases.

The Nuclear Taboo May Be Losing Its Strength

Following the bombings of Hiroshima and Nagasaki, an informal but powerful social norm emerged against the use of nuclear weapons. Although nuclear weapons remained central to military strategy throughout the Cold War, the public generally viewed their use as morally unacceptable because of the catastrophic humanitarian consequences.

The study argues that this taboo may be weakening as the events of 1945 move further from living memory. During conflicts such as the Korean and Vietnam Wars, policymakers understood the devastation of Hiroshima and Nagasaki remained highly visible in the public consciousness.

As the emotional impact of these tragedies fades, survey participants appear more willing to view nuclear weapons as an extreme but usable military option rather than uniquely unacceptable weapons. People’s perceptions of risk are heavily shaped by emotion, meaning the psychological barriers discouraging nuclear use may weaken over time.

Reducing Nuclear Risk by Strengthening Systems

To better understand the practical implications of the study, I spoke with one of its authors, Daniel Post, PhD, a professor at the U.S. Naval War College and a former nuclear strike advisor at STRATCOM.

Dr. Post emphasized the important role policymakers play in designing high-stakes decision making processes and noted that one potential reform would be to limit the president’s authority in situations that are not time-urgent.

“At a minimum, procedures could require consultation from a wide range of advisors and agencies such as their cabinet, military advisors, and the NSC to prevent a cognitive bias-heavy decision for proactive nuclear use,” he explained “Ultimately, there is little benefit to sole presidential authority in situations that are not time critical.”

NTI’s work focuses on reducing nuclear risk by strengthening the systems and policies that guide decision-making before a crisis occurs.

This study is particularly valuable because it challenges the assumption that nuclear decision-making is driven solely by strategy and rational calculation. Instead, it highlights the reality that decisions about nuclear weapons are ultimately made by people, and people are influenced by cognitive biases, emotions, and their own perceptions of risk.

This study highlights the importance of the human dimension of nuclear security. Whether examining public attitudes toward nuclear weapons or the choices made by political leaders during a crisis, understanding how people think and make decisions is an important part of reducing nuclear risk. The study makes a strong case that psychology is not separate from nuclear policy. Rather, it is central to it.

The views of Dr. Daniel Post are his own and do not represent or reflect those of the U.S. Naval War College, the U.S. Navy, or any other government agency.