The act-pattern model of altruism is primarily a brand-equity model, which holds that being altruistic can be traded for social benefits. This is a variant of the “selfish” altruism that Rachlin decries, with altruism being dictated by cold calculations. Moreover, personal and social “self-control” may not be as similar as Rachlin suggests – although we have good (biological) reasons to sacrifice the interests of our current selves in favour of our future selves, we have no such reason to sacrifice ourselves for our neighbours. When we do sacrifice ourselves – giving in to true altruism – we will be repaid with extinction.

Despite challenges on minimum necessary competence, intentionality, reliability, and context, the example of cognitive archaeology presented in the target article holds up well. The commentaries also present perspectives on cognition and symmetry that suggest an alternative to the target article's characterization of the cognitive abilities of early Homo erectus. However, the major conclusion of the initial argument – that the human ability to coordinate shape recognition and spatial cognition evolved hundreds of thousands of year ago in conditions unlike those of the modern world – remains intact.

Norman's reconciliation of the two theories of perception is challenged because it directly leads to the nature-nurture dichotomy in the development of the two visual systems. In contrast, the proposition of a separate development of the two visual systems may be better understood as involving different types of information that follow a distinct temporal sequence.

This commentary suggests how Norman's dual control model of vision can be fitted into a broader general model of the control of behaviour by direct (on-line) and indirect (off-line) processes. Some general principles of behavioural organization, development, and competition are described and their specific application to vision is noted.

Rachlin's argument rests on his definition of an altruistic action. Three main features characterize this definition: An altruistic act (1) always has a negative value, (2) is a subset of self-controlled actions, and (3) is meaningful only in the context of repeated interactions. All three features are highly questionable.

Altruism and cooperation are explained as learned behaviors arising from a pattern of repeated acts whose acquired value outweighs the short-term gains following single acts. But animals and young children, tempted by immediate gains, have difficulty learning behaviors of self-control. An alternative source of reinforcement, shared by animals and humans, arises from social interaction that normally accompanies cooperation and altruism in nature.

My response and reactions to the quite diverse commentaries are presented. Among the topics covered are a response to holders of the ecological viewpoint; memory and learning in the two perceptual systems; development of the two systems; biological motion; size and distance perception; illusion and the two systems; and several others. It is suggested that the dual-process approach is a viable working theory of space perception and, perhaps, of other types of perception as well. Hopefully, future research will enhance it with added refinements and variations on the original theme.

In her Behavioral and Brain Sciences target article, Greenfield (1991) proposed that early in a child's development Broca's area may serve the dual function of coordinating object assembly and organizing the production of structured utterances. As development progresses, the upper and lower regions of Broca's area become increasingly specialized for motor coordination and speech, respectively. This commentary presents a connectionist simulation of aspects of this proposal. The results of the simulation confirm the main thrust of Greenfield's argument and suggest that an important impetus for the developmental differentiation in Broca's area may be the increasing complexity of the computational demands made upon it.

Internal mechanisms, especially those implicating the self, are crucial for the egoism-altruism debate. Self-liking is extended to close others and can be extended, through socialization and reinforcement experiences, to non-close others: Altruistic responses are directed toward others who are included in the self. The process of self-extension can account for cross-situational variability, contextual variability, and individual differences in altruistic behavior.

I argue that Rachlin's notion of self-control is imprecise and not well suited to the discussion of altruism. Rachlin's broader agenda, to improve collective welfare by identifying behavioral mechanisms that increase altruism, neglects the fact that altruism is neither necessary nor sufficient for desirable social outcomes.

Ronan Reilly's connectionist simulation both strengthens and advances the theoretical model presented in my 1991 target article, “Language, Tools, and Brain: The Ontogeny and Phylogeny of Hierarchically Organized Sequential Behavior.” Reilly has tested the whole ontogenetic model with a single simulation study explicitly planned for this purpose. His methodology has established that the various components of the theoretical model imply and are compatible with one another. It has also indicated how learning can actualize a pre-established ontogenetic sequence of combining lingusitic symbols and objects. His simulation suggests that the acquisition of linguistic speech may be facilitated by experience with object manipulation, but not vice versa. This hypothesis can and should be empirically tested through research on behavioral development in the two domains. Finally, Reilly has simulated brain architecture, as well as neural learning. His simulation therefore shows how the development of language and object manipulation can result from an interaction between preprogrammed neural architecture (analogous to network architecture) and experience (analogous to the network's training cycles).

We agree with Rachlin's aim to account for altruism within existing theory. However, his argument is implicitly dependent on social and cognitive constructs that are explicitly identified in other social-psychological theories. The account does not advance theory beyond available constructs (e.g., self-categorizations, motives, values, role-identities, and social structure), and Rachlin's implicit use of these strains the behaviorist account.

Rachlin provides an impressive integrative view of altruism and selfishness that helps us correct older views. He presents a highly general theory, even though he is aware of context-dependence of key notions, including altruism. The context-dependence should extend much farther than Rachlin allows it to go. We had better replace theoretical notions of altruism and selfishness by common sense.

As support for his position, Rachlin refers to the writings of Aristotle. However, Aristotle, like many social psychological theorists, would dispute the assumptions that altruism always involves self-control, and that altruism is confined to acts that have group benefits. Indeed, for Aristotle, as for equity theory and sociobiology, justice exists partly to curb the unrestrained actions of those altruists who are a social liability.

On a proximate level, altruism may well be a temporally extended pattern of behavior that often seems to be maintained without extrinsic rewards (we may find it just valuable to be an altruistic person). However, recent theory and experiments have uncovered significant and often nonobvious extrinsic rewards for “altruistic” behavioral patterns. Ultimately, these patterns may mostly lead to a net benefit.

Rachlin favors following patterns over making decisions case by case. However, his accounts of self-control and altruism do not establish the rationality of making decisions according to patterns. The best arguments for using patterns as a standard of evaluation appeal to savings in cognitive costs and compensation for irrational dispositions. What the arguments show depends on how they are elaborated and refined.

Rachlin's substantive points about the relationship between altruism and self-control are obscured by simplistic and outdated portrayals of evolutionary psychology in relation to learning theory.

It is assumed that self-control always has a higher value. What if it does not? Furthermore, although there are clearly intrinsic reinforcers, their measurement is problematic, especially for a behavioral analyst. Finally, is it more parsimonious to postulate that these behaviors are acquired rather than genetically based?

Rachlin rightly highlights behavioural reinforcement, conditional cooperation, and framing. However, genes may explain part of the variance in altruistic behaviour. Framing cannot be used to support his theory of altruism. Reinforcement of acts is not identical to reinforcement of patterns of acts. Further, many patterns of acts could be reinforced, and Rachlin's altruism is not the most likely candidate.

The new emphasis that Rachlin gives to social learning is welcome, because its role in the emergence of altruism and communication is often underestimated. However, Rachlin's account is underspecified and therefore not satisfactory. I argue that recent computational models of the evolution of language show an alternative approach and present an appealing perspective on the evolution and acquisition of a complex, altruistic behavior like syntactic language.