The von Hippel & Trivers theory of self-deception will gain added traction by identifying psychological design features that come into play in different domains of deception. These include the domains of mating, kinship, coalition formation, status hierarchy negotiation, parenting, friendship, and enmity. Exploring these domains will uncover psychological adaptations and sex-differentiated patterns of self-deception that are logically entailed by their theory.

We agree with Jones & Love (J&L) that much of Bayesian modeling has taken a fundamentalist approach to cognition; but we do not believe in the potential of Bayesianism to provide insights into psychological processes. We discuss the advantages of associative explanations over Bayesian approaches to causal induction, and argue that Bayesian models have added little to our understanding of human causal reasoning.

It is consistent with the evidence in The Origin of Concepts to conjecture that infants' causal representations, like their numerical representations, are not continuous with adults', so that bootstrapping is needed in both cases.

Mercier and Sperber (M&S) sketch a bleak picture of logical reasoning in classic, nonargumentative tasks. I argue that recent processing data indicate that despite people's poor performance they at least seek to adhere to traditional logical norms in these tasks. This implies that classic reasoning tasks are less artificial–and logical reasoning less exceptional–than M&S's framework suggests.

Carey speculates that the representations of core cognition are entirely iconic. However, this idea is undercut by her contention that core cognition includes concepts such as object and agency, which are employed in thought as predicates. If Carey had taken on board her claim that core cognition is iconic, very different hypotheses might have come into view.

Grounded cognition offers a natural approach for integrating Bayesian accounts of optimality with mechanistic accounts of cognition, the brain, the body, the physical environment, and the social environment. The constructs of simulator and situated conceptualization illustrate how Bayesian priors and likelihoods arise naturally in grounded mechanisms to predict and control situated action.

Seeking integration of drug consumption research by a theory of memory function and emphasizing drug consumption rather than addiction, Müller & Schumann (M&S) treat drug self-administration as part of a general pattern of consumption. This insight is located within a more comprehensive framework for understanding drug use as consumer behavior that explicates the reinforcement contingencies associated with modes of drug consumption.

von Hippel & Trivers's central assertion that people self-deceive to better deceive others carries so many implications that it must be taken to the laboratory to be tested, rather than promoted by more indirect argument. Although plausible, many psychological findings oppose it. There is also an evolutionary alternative: People better deceive not through self-deception, but rather by not caring about the truth.

A critique of inferences from “is” to “ought” plays a central role in Elqayam & Evans' (E&E's) defense of descriptivism. However, the reflective equilibrium strategy described by Goodman and embraced by Rawls, Cohen, and many others poses an important challenge to that critique. Dual-system theories may help respond to that challenge.

The biological function of human reasoning abilities cannot be to improve shared knowledge. This is at best a side effect. A more plausible function of argumentation, and thus of reasoning, is to advertise one's ability to detect lies and errors. Such selfish behavior is closer to what we should expect from a naturally selected competence.

Von Hippel & Trivers reason that the potential benefits of successfully deceiving others provide a basis for the evolution of self-deception. However, as self-deceptive processes themselves provide considerable adaptive value to an individual, self-deception may have evolved as an end in itself, rather than as the means to an end of improving other-deception.

Elqayam & Evans (E&E) argue against prescriptive normativism and in favor of descriptivism. I challenge the assumption, implicit in their article, that there is a choice to be made between the two approaches. While descriptivism may be the right approach for some questions, others call for a normativist approach. To illustrate the point, I briefly discuss two questions of the latter sort.

The potential to instrumentalize drug use based upon the detection of very many different drug states undoubtedly exists, and such states may play a role in psychiatric and many other drug uses. Nevertheless, nonaddictive drug use is potentially more parsimoniously explained in terms of sensation seeking/impulsivity and drug expectations. Cultural factors also play a major role in nonaddictive drug use.

Jones & Love (J&L) suggest that Bayesian approaches to the explanation of human behavior should be constrained by mechanistic theories. We argue that their proposal misconstrues the relation between process models, such as the Bayesian model, and mechanisms. While mechanistic theories can answer specific issues that arise from the study of processes, one cannot expect them to provide constraints in general.

There is indeed extensive evidence that people perform fairly poorly in reasoning tasks and that they often construct arguments for intuitively cued responses. Mercier & Sperber (M&S) may also be right to claim that reasoning evolved primarily as argumentation. However, if it did, the facility became exapted to the function of supporting uniquely human abilities for reflective thinking and consequential decision making.

This article defends a continuity position. Infants can abstract numerosity and young preschool children do respond appropriately to tasks that tap their ability to use a count and cardinal value and/or arithmetic principles. Active use of a nonverbal domain of arithmetic serves to enable the child to find relevant data to build knowledge about the language and use rules of numerosity and quantity.

We argue that Bayesian models are best categorized as methodological or theoretical. That is, models are used as tools to constrain theories, with no commitment to the processes that mediate cognition, or models are intended to approximate the underlying algorithmic solutions. We argue that both approaches are flawed, and that the Enlightened Bayesian approach is unlikely to help.

Elqayam & Evans' (E&E's) critique of normativism is related to an inherently philosophical question: Is thinking a normative affair? Should thinking be held accountable towards certain norms? I present the historical and philosophical origins of the view that thinking belongs to the realm of normativity and has a tight connection with logic, stressing the pivotal role of Kant in these developments.

The newly proposed framework for non-addictive psychoactive substances postulated by Müller & Schumann (M&S) provides an interesting and plausible explanation for non-addictive drug use. However, with specific reference to the relevant behavioral addiction literature, this commentary argues that the model may unexpectedly hold utility not only for non-addictive use of drugs, but also for non-addictive use of other potentially addictive behaviors.

This commentary describes another variety of self-deception, highly relevant to von Hippel & Trivers's (VH&T's) project. Drawing on dual-process theories, I propose that conscious thinking is a voluntary activity motivated by metacognitive attitudes, and that our choice of reasoning strategies and premises may be biased by unconscious desires to self-deceive. Such biased reasoning could facilitate interpersonal deception, in line with VH&T's view.