SummaryPolitical ideologies summarize dimensions of life that define how a person organizes their public and private behavior, including their attitudes associated with sex, family, education, and personal autonomy [1, 2]. Despite the abstract nature of such sensibilities, fundamental features of political ideology have been found to be deeply connected to basic biological mechanisms [3–7] that may serve to defend against environmental challenges like contamination and physical threat [8–12]. These results invite the provocative claim that neural responses to nonpolitical stimuli (like contaminated food or physical threats) should be highly predictive of abstract political opinions (like attitudes toward gun control and abortion) [13]. We applied a machine-learning method to fMRI data to test the hypotheses that brain responses to emotionally evocative images predict individual scores on a standard political ideology assay. Disgusting images, especially those related to animal-reminder disgust (e.g., mutilated body), generate neural responses that are highly predictive of political orientation even though these neural predictors do not agree with participants’ conscious rating of the stimuli. Images from other affective categories do not support such predictions. Remarkably, brain responses to a single disgusting stimulus were sufficient to make accurate predictions about an individual subject’s political ideology. These results provide strong support for the idea that fundamental neural processing differences that emerge under the challenge of emotionally evocative stimuli may serve to structure political beliefs in ways formerly unappreciated.

The readiness potential (RP)—a key ERP correlate of upcoming action—is known to precede subjects' reports of their decision to move. Some view this as evidence against a causal role for consciousness in human decision-making and thus against free-will. But previous work focused on arbitrary decisions—purposeless, unreasoned, and without consequences. It remains unknown to what degree the RP generalizes to deliberate, more ecological decisions. We directly compared deliberate and arbitrary decision-making during a $1000-donation task to non-profit organizations. While we found the expected RPs for arbitrary decisions, they were strikingly absent for deliberate ones. Our results and drift-diffusion model are congruent with the RP representing accumulation of noisy, random fluctuations that drive arbitrary—but not deliberate—decisions. They further point to different neural mechanisms underlying deliberate and arbitrary decisions, challenging the generalizability of studies that argue for no causal role for consciousness in decision-making to real-life decisions.Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).

Adolescents routinely take risks that impact the well-being of the friends they are with. However, it remains unclear when and how consequences for friends factor into decisions to take risks. Here we used an economic decision-making task to test whether risky choices are guided by the positive and negative consequences they promise for peers. Across a large developmental sample of participants ages 12-25, we show that risky decision computations increasingly assimilate friends' outcomes throughout adolescence into early adulthood in an asymmetric manner that overemphasizes protecting friends from incurring loss. Whereas adults accommodated friend outcomes to a greater degree when the friend was present and witnessing these choices, adolescents did so regardless of whether a friend could witness their decisions, highlighting the fundamentality of adolescent social motivations. By demonstrating that outcomes for another individual can powerfully tune an actor's risk tolerance, these results identify a key factor underlying peer-related motivations for risky behavior, with implications for the law and risk-prevention. (PsycINFO Database Record

The use of neuroscience in the courtroom can be traced back to the early twentieth century. However, the use of neuroscientific evidence in criminal proceedings has increased significantly over the last two decades. This rapid increase has raised questions, among the media as well as the legal and scientific communities, regarding the effects that such evidence could have on legal decision makers. In this article, we first outline the history of neuroscientific evidence in courtrooms and then we provide a review of recent research investigating the effects of neuroscientific evidence on decision-making broadly, and on legal decisions specifically. In the latter case, we review studies that measure the effect of neuroscientific evidence (both imaging and nonimaging) on verdicts, sentencing recommendations, and beliefs of mock jurors and judges presented with a criminal case. Overall, the reviewed studies suggest mitigating effects of neuroscientific evidence on some legal decisions (e.g., the death penalty). Furthermore, factors such as mental disorder diagnoses and perceived dangerousness might moderate the mitigating effect of such evidence. Importantly, neuroscientific evidence that includes images of the brain does not appear to have an especially persuasive effect (compared with other neuroscientific evidence that does not include an image). Future directions for research are discussed, with a specific call for studies that vary defendant characteristics, the nature of the crime, and a juror's perception of the defendant, in order to better understand the roles of moderating factors and cognitive mediators of persuasion.

Manipulation by another person often undermines freedom. To explain this, a distinction is drawn between two forms of manipulation: indoctrination is defined as causing another person to respond to reasons in a pattern that serves the manipulator's ends; coercion as supplying another person with reasons that, given the pattern in which he responds to reasons, lead him to act in ways that serve the manipulator's ends. It is argued that both forms of manipulation undermine freedom because manipulators track the compliance of their victims, while neutral causal mechanisms do not. Manipulators see to it that their victims comply even in the face of forces that threaten to derail them from the manipulator's desired course. It is suggested that this has an impact on freedom because part of what we desire in wanting to be free is the availability of forms of life very different from those we actually enjoy.