Socioeconomic disparities harm social cognition

Socioeconomic disparities impact neurocognitive functions. Yet, despite decades of research, the relationship between socioeconomic disparities and social cognition (the mental processes that allow us to understand and interact with others) remains controversial. Fendinger and colleagues [1] examine evidence spanning from psychology to the neurosciences and conclude that lower social class is consistently associated with improved social cognition, even if it diminishes more general cognitive processes. The authors suggest that social and nonsocial cognition are dissociable at the behavioral and brain levels, advocating for a domain-specific approach. Here, we argue that the alleged effect of lower social class on improving social cognition is inconsistent. Finally, we discuss how population diversity and current brain–behavior frameworks [2] better account for the impact of socioeconomic disparities on social cognition.

As defined by Fendinger and colleagues, social class is a hierarchy in society based on wealth and social prestige, incorporating cultural aspects that influence norms, values, and behaviors within each class [1]. While usually linked to socioeconomic status, this is not always the case. For instance, cultural aspects such as bilingualism may be associated with higher socioeconomic status in Latin America but not India. However, authors typically evaluate social class using subjective or objective measures of socioeconomic status [3]. Subjective measures include social class identity (poor, middle-class, upper-class) and the MacArthur Ladder, in which individuals indicate their position relative to others regarding socioeconomic measures, such as money, education, and job prestige. Objective measures typically include income and education. Crucially, subjective and objective social class (or socioeconomic) measures are only modestly correlated [3].

Fendinger and colleagues state that ‘lower social class individuals consistently outperform their higher-class counterparts on tasks assessing social cognition’ [1] (p. 528). However, this conclusion draws on reports using subjective measures (social class identity and ladder ratings). With few exceptions, research using objective measures like income or education shows a different pattern, linking lower social class with worse social cognition (i.e., emotion perception and mentalizing) [4–6] and prosociality [7]. Select examples are provided in Table 1, but these are by no means exhaustive.

Table 1.

Factors linked with worse social cognition and prosociality across studies

	Key findings	Refs
Lower objective social class	Associations between lower subjective social class and better social cognition/prosociality usually do not hold when using objective measures.	[4,7]
	Lower education, childhood family income, parental education, and socioeconomic status are associated with diminished social cognition (emotion perception and mentalizing).	[4–6]
	Lower income, education, occupational prestige, neighborhood deprivation, and economic inequality are associated with reduced prosociality (e.g., helping, trust).	[7]
Population diversity	Associations between lower social class and better social cognition and prosociality typically found in homogeneous samples do not generalize to more extensive, diverse, and international samples.	[4,7]
	Studies using samples from under-represented developing nations (e.g., Argentina, Brazil, Colombia) link socioeconomic disparities with worse social cognition.	[5,6]

The aforementioned evidence is not addressed in Fendinger’s work. The authors also neglect contradicting results in a report they cite [8]. In Bjornsdottir and colleagues [8], associations between lower subjective social class and better interpersonal accuracy disappeared when using objective measures and lower income predicted worse mentalizing. Thus, Fendinger’s conclusion might be valid only for subjective measures, which likely capture other factors (hierarchy, power) that may influence social cognition differently than socioeconomic disparities.

Another concern is population biases. Evidence scrutinized by Fendinger and colleagues largely stems from young and healthy students/workers in the USA. A different outlook emerges from the population diversity of non-WEIRD (western, educated, industrialized, rich, and democratic) nations (Table 1). There is no association between lower social class and higher emotion perception or enhanced prosocial behavior in more extensive and socio-demographically diverse samples [4,7]. As shown for cognition and functionality [9], socioeconomic disparities significantly burden social cognition in under-represented backgrounds [6,10]. Embracing population and cultural diversity seems critical to advance a global understanding of socioeconomic disparities and social cognition.

Finally, Fendinger’s domain-specific approach lacks current support. They state that social and nonsocial cognition are dissociable and rely on separate brain regions differentially impacted by social class. Lower social class may enhance social cognition by promoting activity in the dorsomedial prefrontal cortex. Conversely, lower social class either has no impact on nonsocial cognition or hinders it through other regions. However, at the behavioral level, evidence of blending between cognitive/executive functions and social cognition [2,10] contradicts such dissociation. Regarding neural correlates, social cognition broadly extends beyond the dorsomedial prefrontal cortex, involving ‘nonsocial regions’ like the premotor and intraparietal cortices [11]. Similarly, nonsocial cognition critically engages ‘social regions’, including the dorsomedial prefrontal cortex [11]. Socioeconomic disparities are associated with reduced cortical surface of multiple regions relevant to cognitive/executive functions and social cognition [12]. Socioeconomic-related brain differences may even not manifest quantitatively (i.e., less brain activity) but qualitatively (i.e., engaging different neurocognitive systems) [12]. Together, Fendinger’s assumption of a selective boost of lower social class on the ‘social brain’ seems oversimplistic. Assuming rigid anatomical categorizations without considering the degeneracy principle (same function performed by different structures) and network dynamics represents an outdated localizationist framework that can lead to inaccuracies [2].

At the very least, lower social class does not consistently improve social cognition but can indeed harm it. Lower subjective social class has been associated with enhanced social cognition in the USA. However, lower objective social class, particularly across diverse samples, seems to involve diminished social cognition. This conclusion has not only research relevance but also ethical: neglecting the negative impact of socioeconomic disparities in underserved populations can increase inequalities. A situated, diverse, and global approach is required to develop tailored models that surpass the failures of universal generalizations [9]. This may allow us to better understand how socioeconomic disparities shape the human brain and cognition.