Understanding the effects of serotonin in the brain through its role in the gastrointestinal tract.

The neuromodulatory arousal system imbues the nervous system with the flexibility and robustness required to facilitate adaptive behaviour. While there are well understood mechanisms linking dopamine, noradrenaline and acetylcholine to distinct behavioural states, similar conclusions have not been as readily available for serotonin. Fascinatingly, despite clear links between serotonergic function and cognitive capacities as diverse as reward processing, exploration, and the psychedelic experience, over 95% of the serotonin in the body is released in the gastrointestinal tract, where it controls digestive muscle contractions (peristalsis). Here, we argue that framing neural serotonin as a rostral extension of the gastrointestinal serotonergic system dissolves much of the mystery associated with the central serotonergic system. Specifically, we outline that central serotonin activity mimics the effects of a digestion/satiety circuit mediated by hypothalamic control over descending serotonergic nuclei in the brainstem. We review commonalities and differences between these two circuits, with a focus on the heterogeneous expression of different classes of serotonin receptors in the brain. Much in the way that serotonin-induced peristalsis facilitates the work of digestion, serotonergic influences over cognition can be reframed as performing the work of cognition. Extending this analogy, we argue that the central serotonergic system allows the brain to arbitrate between different cognitive modes as a function of serotonergic tone: low activity facilitates cognitive automaticity, whereas higher activity helps to identify flexible solutions to problems, particularly if and when the initial responses fail. This perspective sheds light on otherwise disparate capacities mediated by serotonin, and also helps to understand why there are such pervasive links between serotonergic pathology and the symptoms of psychiatric disorders.

Unification at the cost of realism and precision.

Veissière et al. must sacrifice explanatory realism and precision in order to develop a unified formal model. Drawing on examples from cognitive archeology, we argue that this makes it difficult for them to derive the kinds of testable predictions that would allow them to resolve debates over the nature of human social cognition and cultural acquisition.

Temporal updating, behavioral learning, and the phenomenology of time-consciousness.

Hoerl & McCormack claim that the temporal updating system only represents the world as present. This generates puzzles regarding the phenomenology of temporal experience. We argue that recent models of reinforcement learning suggest that temporal updating must have a minimal temporal structure; and we suggest that this helps to clarify what it means to experience the world as temporally structured.

From objectivized morality to objective morality.

Stanford holds that the externalization and objectivization of moral judgments are what sustain human cooperative lifeways. We reply that the central function of human moral psychology is to track and respond to the structural features of our social environment, and we argue that moral obligations are grounded in the relationship between individual agents and the stability of their social groups.

Cultural evolution and prosociality: Widening the hypothesis space.

Norenzayan et al. suggest that Big Gods can be replaced by Big Governments. We examine forms of social and self-monitoring and ritual practice that emerged in Classical China, heterarchical societies like those that emerged in pre-Columbian Mesoamerica, and the contemporary Zapatista movement of Chiapas, and we recommend widening the hypothesis space to include these alternative forms of social organization.

Is costly punishment altruistic? Exploring rejection of unfair offers in the Ultimatum Game in real-world altruists.

In the Ultimatum Game (UG), incurring a cost to punish inequity is commonly termed altruistic punishment. This behaviour is thought to benefit others if the defector becomes more equitable in future interactions. However, clear connections between punishment in the UG and altruistic behaviours outside the laboratory are lacking. We tested the altruistic punishment hypothesis in a sample of extraordinarily altruistic adults, predicting that if punishing inequity is predictive of altruism more broadly, extraordinary altruists should punish more frequently. Results showed that punishment was not more prevalent in extraordinary altruists than controls. However, a self-reported altruism measure previously linked to peer evaluations but not behaviour, and on which extraordinary altruists and controls did not differ, did predict punishment. These findings support suggestions that altruistic punishment in the UG is better termed costly punishment and may be motivated by social, but not necessarily prosocial, concerns. Results also support prior suggestions that self-reported altruism may not reliably predict altruistic behaviour.

Accountability and values in radically collaborative research.

This paper discusses a crisis of accountability that arises when scientific collaborations are massively epistemically distributed. We argue that social models of epistemic collaboration, which are social analogs to what Patrick Suppes called a "model of the experiment," must play a role in creating accountability in these contexts. We also argue that these social models must accommodate the fact that the various agents in a collaborative project often have ineliminable, messy, and conflicting interests and values; any story about accountability in a massively distributed collaboration must therefore involve models of such interests and values and their methodological and epistemic effects.

Massively representational minds are not always driven by goals, conscious or otherwise.

The language of conscious and unconscious goals is rooted in a folk-taxonomy that is likely to inhibit progress in cognitive science. Severing the commitment to this taxonomy would allow Huang & Bargh (H&B) to consider a wider variety of representational forms with motivational force and to entertain the intriguing possibility that variations in the number of active-but-redundant representations account for variance in social behavior.

Tool use as situated cognition.

Vaesen disregards a plausible alternative to his position, and so fails to offer a compelling argument for unique cognitive mechanisms. We suggest an ecological alternative, according to which divergent relationships between organism and environment, not exotic neuroanatomy, are responsible for unique cognitive capacities. This approach is pertinent to claims about primate cognition; and on this basis, we argue that Vaesen's inference from unique skills to unique mechanisms is unwarranted.

The linguistic analogy: motivations, results, and speculations.

Inspired by the success of generative linguistics and transformational grammar, proponents of the linguistic analogy (LA) in moral psychology hypothesize that careful attention to folk-moral judgments is likely to reveal a small set of implicit rules and structures responsible for the ubiquitous and apparently unbounded capacity for making moral judgments. As a theoretical hypothesis, LA thus requires a rich description of the computational structures that underlie mature moral judgments, an account of the acquisition and development of these structures, and an analysis of those components of the moral system that are uniquely human and uniquely moral. In this paper we present the theoretical motivations for adopting LA in the study of moral cognition: (a) the distinction between competence and performance, (b) poverty of stimulus considerations, and (c) adopting the computational level as the proper level of analysis for the empirical study of moral judgment. With these motivations in hand, we review recent empirical findings that have been inspired by LA and which provide evidence for at least two predictions of LA: (a) the computational processes responsible for folk-moral judgment operate over structured representations of actions and events, as well as coding for features of agency and outcomes; and (b) folk-moral judgments are the output of a dedicated moral faculty and are largely immune to the effects of context. In addition, we highlight the complexity of the interfaces between the moral faculty and other cognitive systems external to it (e.g., number systems). We conclude by reviewing the potential utility of the theoretical and empirical tools of LA for future research in moral psychology.

The role of emotion in moral psychology.

Recent work in the cognitive and neurobiological sciences indicates an important relationship between emotion and moral judgment. Based on this evidence, several researchers have argued that emotions are the source of our intuitive moral judgments. However, despite the richness of the correlational data between emotion and morality, we argue that the current neurological, behavioral, developmental and evolutionary evidence is insufficient to demonstrate that emotion is necessary for making moral judgments. We suggest instead, that the source of moral judgments lies in our causal-intentional psychology; emotion often follows from these judgments, serving a primary role in motivating morally relevant action.