Constraints on Cognitive Evolution

This article explores the cognitive mechanisms behind the human tendency to encode an individual’s race. The authors argue that since genetic evidence shows humanity is not divided into distinct biological races, the brain mechanisms for encoding race cannot have evolved for that specific purpose. Instead, race encoding must be a by-product of computational machinery that evolved for an alternative function.

The article evaluates three main hypotheses for this phenomenon:

1. Perceptual/Correlational Systems: This view suggests race is encoded as a by-product of general-purpose systems that detect perceptual clusters like skin colour. However, the authors present evidence against this, noting that colour encoding is not automatic when it lacks social significance and that instructions affecting perceptual tasks do not alter race encoding.

2. Essentialist Reasoning: This hypothesis posits that race encoding is a by-product of an inference system designed for reasoning about “natural kinds” (like animal species). This system treats racial groups as if they have deep, underlying essences, which would explain why people make strong inferences about traits based on race.

3. Coalitional Psychology: The authors’ preferred hypothesis is that race encoding is a by-product of cognitive machinery that evolved for tracking shifting alliances and coalitions. In societies where race is correlated with patterns of cooperation and conflict, the mind uses race as a proxy for coalitional affiliation. Crucially, experiments show that race encoding can be diminished or eliminated when subjects are exposed to a social context where coalition membership is unrelated to race, supporting the idea that this mechanism is flexible and not mandatory.

In conclusion, the authors suggest that different aspects of racial thinking might be generated by different cognitive systems, but the encoding of race itself is best explained as a flexible by-product of an evolved capacity for tracking coalitions.

This article examines why pro-vaccination beliefs struggle to spread while vaccine hesitancy persists, drawing on cultural attraction theory and the concept of epistemic vigilance. The central argument is that pro-vaccination beliefs are counter-intuitive, making them less likely to be accepted and transmitted, whereas anti-vaccination beliefs align better with intuitive cognitive mechanisms.

Several cognitive factors contribute to this:

• Disgust Psychology: An intuitive aversion to contaminants makes people wary of vaccines, which contain small amounts of substances perceived as harmful.

• Omission Bias: People intuitively view harm caused by an action (vaccinating) as morally worse than harm from an inaction (not vaccinating), leading them to fear vaccine side effects more than the diseases they prevent.

• Disease Saliency: The very success of vaccines makes the diseases they prevent less visible, reducing the perceived threat and making pro-vaccination arguments less intuitive.

The article states that counter-intuitive beliefs can spread through trust and argumentation, but both face significant hurdles in the context of vaccination. One-way messaging is often ineffective because it cannot address the specific counter-arguments of individuals. Furthermore, public trust in the institutions promoting vaccines (such as pharmaceutical companies and governments) is often low. The authors conclude that while forceful measures might be necessary in the short term, the long-term solution requires rebuilding trust in scientific and medical institutions.

This academic review article argues against the widespread historical and scholarly belief that humans are strongly gullible. The author, Hugo Mercier, challenges the idea that people are easily fooled into accepting harmful, costly, or empirically unfounded beliefs, particularly from authority figures or demagogues.

Instead, Mercier proposes that humans are equipped with well-functioning cognitive mechanisms of “epistemic vigilance” that allow them to critically evaluate communicated information. These mechanisms include:

• Plausibility Checking: Assessing new information against pre-existing beliefs and rejecting inconsistencies.

• Trust Calibration: Evaluating a source’s trustworthiness based on cues of competence and benevolence.

• Argument Evaluation: Assessing the strength and validity of reasons provided to support a claim.

The article reviews evidence from experimental psychology demonstrating that these mechanisms are generally effective. It then examines various domains often cited as proof of gullibility—such as religion, propaganda, advertising, and politics—and argues that communication in these areas is much less influential than commonly believed. Mercier concludes that when people do accept misguided information, it is often not due to undue deference to a source (source-based processes) but because the information fits with their pre-existing intuitions and beliefs (content-based processes).

In this book, Hugo Mercier makes the case that humans are fundamentally not gullible, challenging the long-held view from scholars and thinkers that portrays the masses as easily misled. He argues against the idea that we credulously accept whatever we are told, even when messages come from prestigious figures or the majority.
Mercier’s core argument is that uncritical acceptance of information is evolutionarily unstable and too costly. To facilitate effective communication while protecting against deception, humans evolved a suite of cognitive mechanisms he calls “open vigilance mechanisms”. These tools allow us to be open to beneficial information while remaining vigilant against harmful messages. They work by evaluating the message’s content (is it plausible? backed by good arguments?) and its source (is the speaker competent and honest?).
The book aims to show that most attempts at mass persuasion, from political campaigns to advertising, are largely unsuccessful. Mercier explains that the spread of popular but mistaken beliefs—from flat-earth theories to political misinformation—is not typically a result of masterful persuasion or blind trust. Instead, such beliefs often succeed because they are intuitive and align with our spontaneous thoughts (e.g., the earth looks flat) or because people profess them for social reasons, rather than truly accepting them as reality. The modern information environment can challenge our vigilance mechanisms, but Mercier maintains that, if anything, we are too resistant to influence, not too open to it.