We suggest that people privilege explanations relying on inherent rather than contingent factors not only because of an innate cognitive tendency to monitor reality, but because doing so satisfies the desire to perceive the societal status quo as legitimate. In support, we describe experimental studies linking the activation of system justification motivation to the endorsement of inherence-based (essentialist) explanations.

In his state-of-the-art review, Gurven compares evolutionary theories of food transfers in ethnographic settings. Although this is useful, I suggest that one must first try to determine the utility of food transfers before making predictions about which parties ought to receive food. In addition, I argue that tests of kin selection theory present a special problem in food transfers.

By delineating the parametric variations that affect infant performance in the standard A-not-B search task, the Thelen et al. model provides an important contribution to the field of infant development. We discuss several broad issues pertinent to interpreting the model. We note that the phenomenon modeled by Thelen et al. is not necessarily the one originally described by Piaget. We describe data on infant self-correction that are not addressed by the Thelen et al. model. Finally, we suggest that psychological constructs such as representation and knowledge structures are valuable to our understanding of the A-not-B phenomenon in particular and psychological development in general.

In the developing and adult cortex, just as in the adult hippocampus, LTP is unable to account for a variety of types of functional plasticity.

Two assertions of Halford et al. are critiqued: their claim of priority in relational complexity analysis and the sufficiency for cognitive development of their relational-complexity analysis of tasks. Critical discussion of concrete task analyses (i.e., the relational complexity of proportionality problems, of balance scale problems, and the Tower of Hanoi) serves, by way of counterexamples, to highlight problems in their method.

This commentary provides a critique of Tsuda's target article, focusing on the hippocampus and episodic long-term memory. More specifically, the relevance of Cantor coding and chaotic itinerancy for long-term memory functioning is considered, given what we know about the involvement of the hippocampus in the mediation of long-term episodic memory (based on empirical neuroimaging studies and investigations of brain-damaged amnesic patients).

Perceptual symbol systems form a theoretically plausible alternative to amodal symbol systems. At this point it is unclear whether there is any truly diagnostic empirical evidence to decide between these systems. We outline some possible avenues of research in the domain of language comprehension that might yield such evidence. Language comprehension will be an important arena for tests of the two types of symbol systems.

Multidimensional scaling of subjective color differences has shown that color stimuli are located on a hypersphere in four-dimensional space. The semantic space of color names is isomorphic with perceptual color space. A spherical four-dimensional space revealed in monkeys and fish suggests the primacy of common neuronal basis.

Norris et al. argue against using evidence from phonetic decision making to support top-down feedback in lexical access on the grounds that phonetic decision relies on processes outside the normal access sequence. This leaves open the possibility that bottom-up connectionist models, with some contextual constraints built into the access process, are still preferred models of spoken-word recognition.

Sign languages provide direct evidence for the relation between human languages and the body that engenders them. We discuss the use of the hands to create symbols and the role of the body in sign language verb systems, especially in two quite recently developed sign languages, Israeli Sign Language and Al-Sayyid Bedouin Sign Language.