The attempt to relate distinctions in perceptual theory to different physiological systems leads to numerous exceptions and inconsistencies. A more promising approach to the reconciliation of constructivist theory and direct perception is to recognize that perception does involve inference, as the constructivists insist, but that inference is a process in logic that does not require unconscious reasoning and need be no more thought-like than resonance.

Many situations in human life present choices between (a) narrowly preferred particular alternatives and (b) narrowly less preferred (or aversive) particular alternatives that nevertheless form part of highly preferred abstract behavioral patterns. Such alternatives characterize problems of self-control. For example, at any given moment, a person may accept alcoholic drinks yet also prefer being sober to being drunk over the next few days. Other situations present choices between (a) alternatives beneficial to an individual and (b) alternatives that are less beneficial (or harmful) to the individual that would nevertheless be beneficial if chosen by many individuals. Such alternatives characterize problems of social cooperation; choices of the latter alternative are generally considered to be altruistic. Altruism, like self-control, is a valuable temporally-extended pattern of behavior. Like self-control, altruism may be learned and maintained over an individual's lifetime. It needs no special inherited mechanism. Individual acts of altruism, each of which may be of no benefit (or of possible harm) to the actor, may nevertheless be beneficial when repeated over time. However, because each selfish decision is individually preferred to each altruistic decision, people can benefit from altruistic behavior only when they are committed to an altruistic pattern of acts and refuse to make decisions on a case-by-case basis.

Intertemporal bargaining theory based on the hyperbolic discounting of expected rewards accounts for how choosing in categories increases self-control, without postulating, as Rachlin does, the additional rewardingness of patterns per se. However, altruism does not seem to be based on self-control, but on the primary rewardingness of vicarious experience. We describe a mechanism that integrates vicarious experience with other goods of limited availability.

Cognitive developmental disorders cannot be properly understood without due attention to the developmental process, and we commend the authors’simulations in this regard. We note the contribution of these simulations to the nascent field of connectionist modeling of developmental disorders and outline a set of criteria for assessing individual models in the hope of furthering future modeling efforts.

The adaptationist and exaptationist programs overlap in their need for a pluralistic approach to understanding evolutionary change, and Andrews et al. effectively illustrate the methodological confounds of these approaches. However, the current critique of adaptationism, especially in the arena of human behavior, rests on the tendency to rapidly reify adaptationist hypotheses prior to broad evidentiary consensus across relevant disciplines.

The parallel drawn by Norman between the dorsal and ventral systems and direct and indirect approaches is based on two misrepresentations of the direct approach – that it is concerned only with the unconscious control of action, and that it cannot explain learning. We propose a way of understanding the visual system differences from within the direct approach.

Long before signs of staged toolmaking appeared, Homo erectus made symmetrical tools. The handaxe is a flattened tear-drop shape, but often with edges sharpened all around. Before we assign their obsession with symmetry to an aesthetic judgment, we must consider whether it is possible that the symmetry is simply very pragmatic for one particular use in the many suggested.

There are good arguments for examining great ape communicative achievements for what they contribute to our understanding of great ape cognition and its evolution (Russon & Begun, in press a). Our concern is whether Shanker & King's (S&K's) thesis advances communication studies from a broader cognitive and evolutionary perspective.

Thomas & Karmiloff-Smith’ (T&K-S’) argument that the Residual Normality assumption is not valid for developmental disorders has implications for models of cognition in schizophrenia, a disorder that may involve a neurodevelopmental pathogenesis. A limiting factor for such theories is the lack of understanding about the nature of the cognitive system (modular components versus global processes). Moreover, it is unclear how the proposal that modularization emerges from developmental processes would change that fundamental question.

The conceptual space< (Gärdenfors 2000) is discussed as a representation structure that connects the constructivist and the ecological vision subsystems in an operating autonomous robot based on computer vision.

We show 13 stages of the development of tool-use and tool making during different eras in the evolution of Homo sapiens. We used the NeoPiagetian Model of Hierarchical Complexity rather than Piaget's. We distinguished the use of existing methods imitated or learned from others, from doing such a task on one's own.

Several lines of evidence have underscored the remarkable neuroplasticity of the primate sensorimotor cortex, characterizing these cortical areas as dynamic constructs that are modelled in a use-dependent manner by behaviourally significant experiences. Their plasticity likely provides a neural substrate that may contribute to the dynamic systems paradigm argued by Shanker & King (S&K) as crucial for development of communication skills.

The fitness maximization standard incorrectly assumes that most adaptations have high heritablility, and it imposes the difficult requirement that correlated phenotypic and environmental contributors to reproduction be controlled for. Despite infrequently recognized problems, the special design standard is the foundation of the spectacular successes of modern medicine. It also suggests that the ancestral environment provides a window into the functioning of the brain.

Rachlin's idea that altruism, like self-control, is a valuable, temporally extended pattern of behavior, suggests one way of addressing common problems in developing a rational choice explanation of individual altruistic behavior. However, the form of Rachlin's explicitly behaviorist account of altruistic acts suffers from two faults, one of which questions the feasibility of his particular behaviorist analysis.

Commitment to a pattern of altruism or self-control may indeed be learnable and sometimes rational. Commitment may also result from illusions. In one illusion, people think that their present behavior causes their future behavior, or causes the behavior of others, when really only correlation is present. Another happy illusion is that morality and self-interest coincide, so that altruism appears self-interested.

Andrews et al. effectively argue that, despite prominent criticism, adaptationism can be a viable research strategy. We agree. In our complementary commentary, we discuss the neglected method of inference to the best explanation and argue that it is a valuable addition to the adaptationist's methodological practice.

Shanker & King (S&K) trumpet the adoption of a “new paradigm” in communication studies, exemplified by ape language research. Though cautiously sympathetic, I maintain that their argument relies on a false dichotomy between “information” and “dynamical systems” theory, and that the resulting confusion prevents them from recognizing the main chance their line of thinking suggests.

Thomas & Karmiloff-Smith (T&K-S) correctly identify Residual Normality (RN) as a critical assumption of some theorising about mental structure within developmental psychology. However, their simulations provide only weak support for the conditions under which RN may occur because they explore closely related architectures that share a learning algorithm. It is suggested that more work is required to establish the limits of RN.

Norman's identification of a ventral system embodying a constructivist theory of perception is rejected in favor of an ecological theory of perception and perceptual learning. We summarize research showing that a key motivation for the ventral-constructivist connection, percept-percept coupling, confuses perceptual and post-perceptual processes

In this commentary, we propose that the shifts in symmetry Wynn documents may be explained in terms of simpler mechanisms than he suggests. Furthermore, we argue that it is dangerous to draw definitive conclusions about the cognitive abilities of a species from the level of symmetry observed in the artefacts produced by that species.