(Brief) Social Neuroscience

Note:   The following is a review of Decety and Leong (2025) which is a 70+ page overview of Social Neuroscience, a new approach in Social Psychology.  The review here in the Blog is done through the lens of Dual Interest Theory – DIT.  Importantly, DIT also originally drew in part on Social Psychology, especially in the empirical techniques used in that field to measure the role of the individual and the social.  The DIT Review is done jointly here by Me&ChatGPT.  The search is for the extent to which DIT is supported by the research in Social Neuroscience, how DIT can help make sense of that research, and what DIT suggests about a future direction for it.

Jean Decety and Yuan Chang Leong's chapter “Social Neuroscience” in the 2025 edition of The Handbook of Social Psychology provides a wide-ranging synthesis of contemporary research on the biological foundations of human sociality as seen through the lens of Social Psychology. Their review covers empathy, social connection, synchrony, social networks, hierarchy, motivated cognition, group processes, social influence, cooperation, and social preferences. Its larger methodological argument is equally important: Explanations of human behavior need to be vertically integrated across biological, psychological, and social levels rather than confined within disciplinary silos.

Read through the lens of Dual Interest Theory (DIT) in Metaeconomics (See FAQ for "what is DIT"), the “Social Neuroscience” chapter in the Handbook of Social Psychology is especially intriguing because much of the research it surveys is compatible with a conception of human choice as arising from jointly operative ego&empathy processes, rather than from ego-based self-interest alone as mainstream economics claims in the use of Single Interest Theory (SIT).  

Also,  an important aside:  DIT uses the “&”  deliberately. Ego&empathy, me&we, self&other, individual&social, and individual&common good are not treated as independent domains subsequently added together. The “&” means jointly arising, interacting, and functionally nonseparable aspects of human choice. In DIT terminology, ego-based self-interest is always operating jointly with an empathy-based other(shared)-interest, with self-command helping regulate where attention is directed and how the resulting valuation is resolved into action. The theoretical objective is not to maximize either side independently but to find a workable, dynamically balanced own-interest.

The “&” is illustrated in Figure 1.  The self-interest tendency of the individual is represented on path 0G.  The social, shared with the other-interest is represented on path 0M. The integration represented in the “&” is represented in the overlap of path 0G and 0M, shifting the focus to path 0Z. On that path, the individual pursues the own-interest --- good balance in self&other --- the best path.  Figure 1 represents the individual operating in a Market Forum.

But, individuals also operate in Other Forums, as represented in Figure 2.  And, many levels are at play, to include the family, extended family, communities (and all the organizations in same, from bowling leagues to book clubs to religious and political), states, and nations. The fact somethings are priceless --- in the domain of the sacred ---  are weighed against the things with a price.  Again, the focus shifts to path 0Z.

DIT suggests an evolutionarily successful economy&society strikes good balance in the Market Forum&Other Forum.  We now turn to exploring how well the DIT analytical system represented in Figure 1 and 2 stands-up to scrutiny when the latest research from Social Neuroscience is brought into view with the DIT lens.

Decety and Leong are Not Pointing to an Empirical Test of DIT

Now, for framing here:  Decety and Leong do not test DIT, and the review cannot be read as demonstrating only the DIT model. The findings do, however, bear directly on several of the central propositions in DIT. Most importantly, social neuroscience increasingly portrays human valuation and choice as emerging from distributed and interacting systems that represent self, other people, affect, social norms, rewards, and social context. That architecture is difficult to reconcile with an empirical theory of human choice in which ego-based material self-interest --- as in SIT, the standard Econ 101 model --- is the sole operative motivation.

Separate Disciplines to Integrated Human Behavior

Decety and Leong begin by describing social neuroscience as an interdisciplinary enterprise connecting biology with psychology and the social sciences. An emphasis is put on  “vertical integration” as in explanations at different levels need not use the same concepts, but they must be mutually compatible. Higher-level constructs developed by economists, sociologists, and psychologists are not to be necessarily reduced to neural activity, but neither can said disciplines  justifiably disregard what research at biological and psychological levels reveals about human behavior.

That methodological position is congenial to DIT. Metaeconomics is an integrated science, and does not seek to replace economics with neuroscience. It seeks an economic abstraction of choice that is compatible with what is known about the evolved human organism as neuroscience and social neuroscience provides. The question for DIT is therefore not whether a specific isocurve or path of best economic&social choice can be located somewhere in the brain. Decety and Leong explicitly caution against such one-to-one mappings. Constructs such as ego, empathy, morality, self-regulation, tempering of excesses, and trust arise from complex interactions across neural and social systems rather than from isolated anatomical locations.

The relevant test is instead whether an economic theory's assumptions about motivation and decision-making are compatible with the architecture revealed at lower levels of analysis. It is at said point that the contrast between Dual Interest Theory (DIT) and  Single Interest Theory (SIT) becomes important, and, at this time, is substantial.

SIT --- the mainstream Microeconomics theory --- in its strongest conventional form represents choice as the exclusive pursuit of ego-based self-interest. Social considerations can be appended to the utility function, but the underlying maximization framework remains centered on an autonomous individual preference ordering.  No social preference is in play, other than as an argument in an individual preference ordering.  In contrast, DIT instead starts from a jointly constituted own-interest: Ego-based self-interest&empathy-based other(shared)-interest, individual&social preferences are both internal to the choosing person.

The evidence reviewed by Decety and Leong is far closer to supporting the DIT story rather than the story weaved by SIT. 

Ego&Empathy: Distinguishable but Jointly Operative

The neuroscience of empathy is particularly revealing. Decety and Leong distinguish affective, cognitive, and motivational dimensions of empathy, as does DIT. Cognitive empathy involves representing and reasoning about the intentions, beliefs, and emotions of both oneself and other people. It is about perspective taking. Affective sharing jointly integrated with perspective-taking can generate motivation --- as in moral considerations in judgement--- to care about another's welfare. Yet said processes do not operate through a single “empathy center.” Said processes rely on distributed, recursively connected and interacting circuitry involving the insula, anterior cingulate cortex, medial prefrontal cortex, temporoparietal junction, striatum, amygdala, orbitofrontal cortex, brainstem, autonomic nervous system, and neuroendocrine systems. In other words, the decision circuitry to include self-command, the self-discipline to act on the empathy-with consideration to temper the ego-drive is in play.

An important conceptual distinction follows. Neurally distinguishable does not mean behaviorally separable.

Researchers can distinguish signals related to self and other, cognitive and affective empathy, rewards, norms, and executive control. But the capacity to distinguish those components experimentally does not establish that they function as independent motivational systems. Indeed, Decety and Leong repeatedly describe social behavior in terms of interactions among said processes.  DIT speaks regularly to such interaction, as in the interaction and integrationin the ego-based self-interest&empathy-based shared with the other-interest, or simply jointly integrated self&other-interest. Said dual interests are interacting and as a result are joint, nonseparable and interdependent --- so, said dual interest is jointly operant. 

That distinction is central to the “&” in  DIT. The DIT claim is that the normally functioning human chooser in both the domain of economy&society --- writ large, the profane&sacred ---cannot adequately be represented by treating the element on either side of the “&” as the real motivation and the other as an occasional external addition. Differentiated information concerning self&other is processed within one interconnected organism and ultimately contributes to one choice.  As is sometimes said in DIT, the Me needs a We to Be, but without a Me there is no We. It is about Me&We, jointly operant.

Decety and Leong point to the reward literature which strengthens said interpretation. Caring for or helping another, joining in shared cause with that other,  can itself produce satisfaction within the own-self. And, it is always  about a bit of sacrifice as in altruism in both domains of interest. Such helping decisions consistently recruit reward and value-computation systems. In DIT terms, in contrast to SIT terms, the empathy-based shared-with-the-other interest is therefore not literally somebody else's utility inserted into my ego-based self-interest oriented utility function. The shared with the other interest is my own internally represented interest is a state of mind involving my own sense of the perspective of the other.

It is what  DIT means in referring to the “shared-with-the-other-interest” or the “other(shared)-interest” or simply the “other-interest.”  It is all going on inside the brain of “me” in referring to my sense of understanding and relationship with the “we”, or, simply me&we, self&other.

Ego Priority Without Ego Exclusivity

DIT has long proposed that ego-based self-interest is comparatively primal, so, in that sense it is consistent with SIT which sees only self-interest.  Yet, DIT makes clear that self-relevant claims often receive priority unless they are tempered through empathy, norms, reflection, and self-command.  Adam Smith called it the arrogance of self-love, i.e., self-interest responding to incentive, which needed to be tempered by the moral sentiment, the ethic. To Adam Smith, it was about striking balance in the joint incentive&ethic, wealth&sentiment.  Decety and Leong provide substantial evidence consistent with that proposition.

The Decety and Leong discussion of cooperation explicitly states that self-interest remains an important motivator even though prosocial and empathic motivations both shape cooperative decision-making. Elsewhere they discuss research showing greater sensitivity to unfairness directed at oneself than to unfairness directed at a neutral other. It is characterized as support for a “me first” mode of processing.

The importance of that evidence for DIT is easily misunderstood. “Me first” does not mean “me only.”

DIT does not reject self-interest. Ego-based self-interest is indispensable, and, a core driver of both biological&cultural evolution, economy&society. Without a viable individual there is no viable social organism: Again, without a Me there is no We. The issue is whether the initial priority given to the self is the whole of human motivation or one component of a jointly constituted own-interest, as in --- again ---  a Me also needs a We to Be. It is about Me&We.

Decety and Leong's review clearly supports the latter. Humans are simultaneously responsive to fairness, reciprocity, reputation, social norms, group membership, relationships, and the welfare of others. Cooperation beyond immediate kin is a defining feature of the species, and early prosocial tendencies emerge during childhood, starting especially after the “terrible 2s.”  And, unfortunately, some never get beyond that stage, as in empathy-with spread widely not ever fully developed.

Thus, DIT's claim is not that empathy replaces ego. It is that the evolved human brain when mentally stable is better represented as the jointly operant ego&empathy, with a natural self-priority operating within, rather than outside of, that joint system.

Self-Command and the Allocation of Attention

This leads to perhaps the most important bridge between DIT and the contemporary neuroscience reviewed by Decety and Leong: Self-command.

DIT borrows Adam Smith's terminology to characterize the capacity to regulate immediate self-regarding impulses by attending to wider consequences, the circumstances of others, social expectations, and shared ethical claims. Like Smith said it, a person needed to Be-Loved&Be-Lovely.  Self-command does not eliminate ego-based self-interest, which led to Be Loved as in the admiration from others, the notion of merit. It influences how heavily different considerations enter the decision process. It was also essential, however, as Smith suggested, that a person temper that self-interest tendency --- the arrogance of self-love --- with what the other could go along with, as in the ethic, the grace.  Said ethic came out of the shared other-interest, which was essential in order to Be Lovely.

Decety and Leong's discussion of cooperation points toward just such an architecture. The research summarized sees three intertwined neural networks involved in human cooperation: A medial network valuing outcomes for self and others; a lateral prefrontal network that modifies value representations in light of local norms; and an anterior prefrontal network involved in reflection, shared social commitments, and arbitration among cooperative norms.

The resemblance to the DIT conception is striking, although it should not be pushed into a one-to-one anatomical identification. The three discrete locations are not discrete, corresponding neatly to ego, empathy, and self-command. Yet, while the claims would be supportive, Decety and Leong also warn against any form of reverse inference.

Yet,  the evidence does support the more general proposition that valuation is subject to attention, modulation, reflection, inhibition, learning, and normative regulation. That suggests a more precise contemporary interpretation of Smithian self-command. Self-command is not simply a brake applied after selfish valuation has already occurred. It can affect what receives attention, how information is interpreted, how norms and consequences are represented, and how competing considerations are weighted during valuation itself.

DIT's metaphorical balance scale should therefore not be read as two independently produced utilities or interests placed on opposite pans. The “scale” represents a dynamically interacting valuation process:

ego-based self-interest&empathy-based other(shared)-interest → attention and reflection → self-command and normative regulation → integrated valuation → choice.

The arrows also run backward. Past choices, habits, institutions, relationships, group identities, and social norms change what people notice and how they subsequently value it.  DIT sees it as the interaction of a jointly operant Market-of-self-interest&Community-of-shared-other-interest

This interpretation helps explain why failures of self-command often favor ego-based claims without requiring the proposition that every prosocial act depends upon conscious suppression of selfishness. Now, to offset that lost self-command, social norms and ethical commitments can themselves become habitual and partially automatic. But where competing considerations arise and reflective regulation is weak, the prepotent “me first” tendency has fewer constraints.

So, DIT provides a considerably richer model of choice than either an ego-only self-interest from SIT model or a simple empathy-based altruism model.

Synchrony, Social Connection, and Common Ground

Decety and Leong's treatment of interpersonal synchrony provides another bridge to DIT. Neural and physiological synchrony increase when people share perspectives, jointly attend to events, communicate effectively, and/or interpret the same events similarly. Social interaction therefore does not merely transmit information between independent decision-makers. Interaction can help generate shared representations.

DIT interprets such processes as potential mechanisms through which other(shared)-interest and common ground are discovered. DIT refers to such common ground being sought in the Other Forums of family, community, market, state and nation.  Said Forums are polycentric, in borrowing said term from Ostrom (2009), in the idea of overlapping Forums.  And, most importantly to the matter of economy, the Market-Forum&Other-Forum are inextricably intertwined.  One cannot function without the other. Writ large, it is about a jointly operant economy&society, and, on an even higher plane, the balancing of the profane&sacred.

Cognitive empathy permits one person to represent the standpoint of another. Communication perhaps influenced by affective empathy giving rise to joint attention can then help identify overlap between interests. When such overlap becomes mutually understood, transaction costs will decline and coordination becomes easier.

But Decety and Leong also make clear why synchrony cannot itself be equated with the common good. People synchronize more strongly with friends, culturally similar people, and ideological in-groups. Shared representations can therefore strengthen factions as readily as broad social cooperation.

That point matters greatly for DIT. Empathy is not automatically universal. The evolved capacity for empathy can also be a form of dark empathy, operating inside narrow boundaries of “us,” leaving an out-group outside the prevailing shared-other interest.  Decety and Leong review evidence of reduced empathy for out-group suffering of the “them” and corresponding reductions in helping behavior.

The DIT objective therefore cannot be simply to maximize empathy or synchrony. It is to enlarge the domain in which cognitive empathy discovers overlapping shared interests across otherwise separated groups.

It is the difference between a narrow factional other(shared)-interest and a more encompassing common good.

Social Networks, Hierarchy, and the Social Construction of Valuation

The social-network and hierarchy literatures further undermine any conception of preferences as wholly autonomous properties of isolated individuals. In effect, using DIT, shared other-interest influences said preferences.

Decety and Leong review evidence that the brain automatically represents social-network information, status, popularity, reputation, and the relationships among other people. Neural systems involved in affective valuation and theory of mind respond not merely to whether a person tends to personally like someone but also to that person's place in the surrounding network.

Similarly, status cues recruit attentional and valuation systems. Humans automatically notice prestige, dominance, expertise, and social rank. Hierarchies can organize cooperation and reduce conflict, but they can also affect stress, health, and behavior.

Through the DIT lens, these findings reinforce a central point: The preferences expressed in a Market Forum are never produced independently of the many Other Forums in which the person is embedded. Again, such Other Forums include families, communities, organizations, cultures, institutions, and governments all  representing and influencing what individuals regard as legitimate, admirable, shameful, fair, sacred, or profitable.

Markets therefore do not operate outside society. The Market-Forum&Other-Forum are jointly operative.

And, bringing Government into view, it is about a joint effort in Market&Community:Government, the “:” meaning an inclusive, representing the entire community --- We the People --- of shared other-interest styled Government.  The Constitutional Republic put into the play in the 1787 U.S. Constitution historically was such a Government. Unfortunately, here in 2026 it is under assault in the move to make it an illiberal democracy at best and an authoritarian autocracy at worst. Social neuroscience also has something  to say about such move.

On the jointness in Market&Community:Government, this does not mean markets are merely cultural constructions in the domain of the sacred or that material incentives in the domain of the profane cease to matter. It means the individual entering a market already carries an internalized social history.

Motivated Cognition and the Imperfect Self-Commanding Agent

Decety and Leong's review of motivated cognition also complicates the standard picture of rational choice. People often perceive and interpret evidence in ways consistent with desired conclusions. Self-enhancement, unrealistic optimism, motivated reasoning, and selective processing can distort not only conscious judgment but potentially earlier stages of information processing.

Said finding has important implications for DIT.

Self-command cannot be conceptualized as a perfectly impartial executive standing outside ego&empathy. The regulatory process itself works with representations already affected by prior beliefs, emotions, identities, and motivations.

People can even reinterpret selfish behavior in ways that preserve a self-image of generosity or fairness. Decety and Leong provide a long discussion of evidence that favorable self-evaluation is often associated with less engagement of controlled processing.

Thus, the problem is deeper than suppressing greed after greed appears. Ego-oriented motivation can affect what is noticed and how reality itself is interpreted.

DIT therefore needs a recursive conception of self-command:

attention shapes valuation; valuation shapes attention; social context shapes both.

It is also where institutions matter. Good working rules in fully functioning institutions do more than constrain behavior after preferences have formed. Institutions repeatedly direct attention, establish expectations, reward certain conduct, stigmatize other conduct, and thereby help form the ethical component of own-interest itself.

Cooperation and the Lmits of Single Interest Theory

The cooperation section is where Decety and Leong come closest to the central economic question addressed in DIT.

It is noted that conventional economic (i.e., SIT) models are commonly based on a self-interest hypothesis and then review evidence that people also care about fairness, reciprocity, norms, reputation, and other people's outcomes. It is noted how human cooperation depends upon the interplay of mental-state representation, emotion, reward, valuation, social norms, and self-regulation.

The broader evolutionary discussion is equally significant. Human beings cooperate extensively with unrelated individuals, including strangers; enforce norms; punish defectors; develop reputations; and create institutions that stabilize cooperative behavior. Yet self-interest persists throughout.

This combination is exactly the empirical territory DIT is intended to represent.

The result is neither:

Homo economicus: ego → choice,

nor:

Homo altruisticus (or sociologicus): empathy → choice.

It is closer to what might be called a Homo homeostaticus:

ego&empathy → self-command and contextual regulation → integrated choice.

The implication for Single Interest Theory – SIT requires some care. Social neuroscience does not demonstrate that standard microeconomic models are useless. Ego-based self-interest remains powerful, and a parsimonious self-interest model may work well in restricted domains where social considerations are weak or held constant or perhaps even irrelevant (like in something like buying a personal item, like a toothbrush). 

Nor is mainstream economics literally devoid of social preferences, norms, identity, altruism, or theories of self-control. A vast behavioral literature has introduced such phenomena, but generally within the flawed framework of self-interest only being in play.

The deeper DIT criticism concerns architecture.

If social considerations are treated simply as additional arguments placed into an otherwise unchanged ego-based, self-interest only utility function, the theoretical framework risks bypassing the very processes that social neuroscience is revealing.  Said reveal points to cognitive empathy, affective response, shared representations, attention, normative learning, social identity, self-command, and the endogenous formation of value.

DIT's other(shared)-interest is therefore not merely another argument in the max U function. Instead, it represents a different dimension of the own-self arising through the relationship of self&other.

Similarly, self-command in DIT is not merely intertemporal discipline—my present self restraining consumption for the benefit of my future self. It includes the Smithian capacity to temper the disproportionate attention naturally given to oneself by cognitively and affectively representing the circumstances of others within the own-self.

In that sense, an ego-only theory not only understates if not outrightly ignores empathy. It also leaves too little  place for the key role of  self-command.

The “Discipline of the Market” and the Discipline Within the Person

The matter of self-command also clarifies an irony surrounding the conventional phrase “the discipline of the market.”

Markets clearly provide external discipline. Prices, losses, competition, contracts, reputation, and the possibility of exit constrain behavior.

But workable markets also depend upon internal discipline, which gives content to that external discipline: Honesty, reciprocity, trust, restraint, willingness to honor commitments, and the ability to perceive the legitimate claims of others. It is not just about the incentive, but is also about the ethic widely shared.

Decety and Leong's neuroscience points toward both dimensions. Human cooperation is sustained through a combination of evolved social capacities and socially created rules, norms, rewards, sanctions, and reputational mechanisms.

The market is therefore not a substitute for self-command. Self-command&Market-discipline operate jointly.

A system relying exclusively on external discipline would face enormous enforcement and transaction costs. Internalized ethical restraint makes exchange itself more feasible.  Transaction costs are minimized through finding common ground in the shared other-interest.

In DIT terms, incentive&ethic are jointly productive.

What Decety and Leong Do—and Do Not—Establish for DIT

The strongest conclusion should remain appropriately bounded.

Decety and Leong do not demonstrate the specific graphical apparatus of DIT.  Decety and Leong do not establish that human beings consciously locate an optimum on a path 0Z, nor identify a measurable neurological “homeostatic point” between ego&empathy. Nor does the fact that social neuroscience documents interactions among individual and social processes prove DIT inherently better than every possible alternative theory of social choice.

What the review does establish with considerable force is a set of empirical constraints any plausible theory of human choice must accommodate, and DIT does so accommodate:

• self-interest remains powerful and often receives processing priority;

• humans also possess evolved capacities for empathy, social connection, fairness, reciprocity, and cooperation;

• self- and other-related information is represented inside the same choosing organism;

• said processes operate through distributed, overlapping, and interacting systems rather than independent psychological compartments;

• attention, norms, executive regulation, social relationships, learning, and context alter valuation and behavior;

• social environments and institutions continually feedback upon biological and psychological processes.

  
  

Taken together, the findings are substantially more compatible with joint-interest theorizing involving ego&empathy than with a literal ego-only account of the human chooser.

A Metaeconomic Interpretation

From the DIT perspective, the emerging social-neuroscience picture can be summarized succinctly.

Humans are neither purely selfish nor purely selfless. They are  jointly selfish&selfless, with the proportions and expressions changing across circumstances. Ego-based self-interest has a powerful and often prior claim on attention. Empathy makes the situations, feelings, intentions, and claims of  individual ego and empathy-with others part of the internal valuation process. Cognitive empathy is especially important because it permits understanding of another standpoint without eliminating the distinction between self&other.

Self-command then helps regulate the jointly operative system. It directs attention, supports reflection, brings norms and longer-run consequences into consideration, and can temper an immediately attractive ego-based response. When it fails, ego-oriented considerations frequently gain greater influence. When empathy-based ethic related considerations become well internalized, however, prosocial conduct need not always require effortful suppression of selfish impulse.

The resulting own-interest is therefore not simply self-interest plus some occasional altruism. It is produced within the interaction:

self-interest&other(shared)-interest

ego&empathy

me&we

incentive&ethic

wealth&moral sentiment

individual&social

individual&common good

profane&sacred.

That is the meaning of the “&” in DIT.

The contribution of Decety and Leong's review is not that it proves DIT in Metaeconomics framing. It is that contemporary social neuroscience increasingly describes the kind of human organism for which such a model is plausible.

The final call for theoretical frameworks capable of integrating social psychology and neuroscience is therefore especially relevant. Social neuroscience has accumulated a remarkable body of evidence concerning the nature of human sociality. The remaining challenge is to build behavioral and social-science theories whose abstractions remain compatible with those findings.

DIT offers one such alternative, and testing to date is giving it solid empirical standing.

The DIT wager is that economics will describe human choice more adequately when it starts neither from an isolated ego nor from an idealized empathy-based social being, but from the evolved, internally conflicted yet integrative human reality of ego&empathy.  The balance is regulated imperfectly through self-command while searching for workable balance in the individual&common good, and, again, the profane&sacred.

References

Decety, Jean and Leong, Yuan Chang. "Social Neuroscience." In The Handbook of Social Psychology, edited by D.T. Gilbert, Fiske, S.T., Finkel, E.J., and Mendes, W.B.: Situational Press, 2025.

Ostrom, Eleanor. "Beyond Markets and States:  Polycentric Governance of Complex Economic Systems." Nobel Prize in Economics Lecture, 2009.