Schilbach et al.'s model assumes that the ability to “experience” minds is already present in human infants and therefore falls foul of the very intellectualist problems it attempts to avoid. We propose an alternative relational, action-based account, which attempts to grasp how the individual's construction of knowledge develops within interactions.

Although the quantum probability (QP) can be useful to model the context effect, it is not relevant to the order effect, conjunction fallacy, and other related biases. Although the issue of potentiality, which is the intuition behind QP, is involved in the context effect, it is not involved in the other biases.

Kurzban and colleagues carry forward an important contemporary movement in cognitive control research, tending away from resource-based models and toward a framework focusing on motivation or value. However, their specific proposal, centering on opportunity costs, appears problematic. We favor a simpler view, according to which the exertion of cognitive control carries intrinsic subjective costs.

Schilbach et al. contrast second-person and third-person approaches to social neuroscience. We discuss relations between second-person and first-person approaches, arguing that they cannot be studied in isolation. Contingency is central for converging first- and second-person approaches. Studies of embodiment show how contingencies scaffold first-person perspective and how the transition from a third- to a second-person perspective fundamentally involves first-person contributions.

Altruism may be learned (behavioral evolution) in a way similar to that proposed in the target article for its biological evolution. Altruism (over social space) corresponds to self-control (over time). In both cases, one must learn to ignore the rewards to a particular (person or moment) and behave to maximize the rewards to a group (of people or moments).

Perceived slope varies with the viewing distance, and is consistent with the effects of foreshortening. Distant viewing makes uphill slopes appear steeper and downhill slopes flatter than does near viewing. These effects are obvious to skiers and climbers in mountainous country. They have also been measured in outdoor experiments with controlled viewing distances. There are many other sources of slope illusions.

A second-person approach that prioritizes dyadic emotional interaction is not well equipped to explain the origins of the understanding of mind conceived as intentionality. Instead, the critical elements that will deliver the understanding of self and other as persons with intentionality are shared object-centered interactions that include not only emotional engagement, but also joint attention and joint goal-directed action.

Baumard et al. make a good case that a sense of fairness evolved and that showing this requires reciprocity games with choice of partner. However, they oversimplify both morality and the evolution of morality. Where fairness is involved in morality, other things are, too, and fairness is often not involved. In the evolution of morality, other things played a role. Plus, the motive for being fair originally was self-interest, not anything moral.

In a surface-dwelling animal like the rat, experimental strategies for investigating the hippocampal correlates of three-dimensional space appear inevitably complicated by the interplay of global versus local reference frames. We discuss the impact of the resulting confounds on present and future empirical analysis of the “bicoded map” hypothesis by Jeffery and colleagues.

According to the foundations of economic theory, agents have stable and coherent “global” preferences that guide their choices among alternatives. However, people are constrained by information-processing and memory limitations and hence have a propensity to avoid cognitive load. We propose that this in turn will encourage them to respond to “local” preferences and goals influenced by context and memory representations.

An opportunity cost model of effort requires flexible integration of valuation and self-control systems. Reciprocal connections between these networks and brainstem neuromodulatory systems are likely to provide the signals that affect subsequent persistence or failure when faced with effort challenges. The interaction of these systems should be taken into account to strengthen a normative neural model of effort.

Baumard et al. argue that partner choice leads to fairness and mutualism, which then form the basis for morality. I comment that mutualism takes us only so far, and I apply the theory of competitive altruism in arguing how strategic investment in behaviours which make one a desirable partner may drive moral conduct.

Faced with probabilistic relationships between causes and effects, quantum theory assumes that deterministic causes do not exist, and that only incomplete probabilistic expressions of knowledge are possible. As in its application to physics, this fundamental epistemological stance severely limits the ability of quantum theory to provide insight and understanding in human cognition.

Kurzban and colleagues propose that experiences of effort alter motivations to persist during goal pursuit by highlighting costs of persistence. I expand this proposal by discussing how effort experiences (a) not only influence, but can be influenced by motivations to persist on a goal; and (b) not only highlight costs that undermine persistence, but can also signal progress and increase persistence.

Interactive approaches to development and social psychology may particularly benefit from the non-dualist features of a second-person neuroscience. In that context, I discuss the compatibility of a second-person neuroscience with a Wittgensteinian analysis of psychological concepts and its connections to a Vygotskyan approach to psychological development.

Although the bicoded map constitutes an interesting candidate representation, proposing it as the predominant representation for three-dimensional space is too restrictive. We present and argue for scalable spatial representation structures as a more comprehensive alternative account that includes the bicoded map as a special case.

We applaud Baumard et al.'s mutualistic account of morality but detect circularity in their articulation of how morality emerged. Contra the authors, we propose that mutualism might account for a sensitivity to convention (the ways things are done within a group) rather than for a sense of fairness. An ontogenetic perspective better captures the complexity of what it means to be moral.

An animal confronts numerous challenges when constructing an optimal navigational route. Spatial representations used for path optimization are likely constrained by critical environmental factors that dictate which neural systems control navigation. Multiple coding schemes depend upon their ecological relevance for a particular species, particularly when dealing with the third, or vertical, dimension of space.

Pothos & Busemeyer (P&B) provide a compelling case that quantum probability (QP) theory is a better match to human judgment than is classical probability (CP) theory. However, any theory (QP, CP, or other) phrased solely at the computational level runs the risk of being underconstrained. One suggestion is to ground QP accounts in mechanism, to leverage a wide range of process-level data.

Although we fundamentally agree with Schilbach et al., we argue here that there is still some residual utility for non-interactive scenarios in social neuroscience. They may be useful to quantify individual differences in prosocial inclination that are not influenced by concerns about reputation or social pressure.