In many conflict situations, defense is easier to mobilize than attack. However, a number of factors, namely, the initial endowments available to each side, the stakes of the conflict, the respective costs of defense and attack, and the way that conflict is framed and perceived, may make attacking more attractive than defending.

Prior to agriculture, human societies were small, with little variation for good genes sexual selection (GGSS) to work on. Across cultures, variation in paternal care makes the benefits of GGSS highly variable. Despite these caveats, female preferences for traits like male body symmetry suggest one reason for female short-term mating is gene shopping.

Lane et al. argue that any psychotherapeutic intervention at its core acts on reactivated memories via the process of reconsolidation which leads to modified memory traces. From our perspective, this model (1) only explains a small subsegment of psychotherapeutic mechanisms and (2) ignores the difficulties of generating reliable experimental conditions that allow interference with reconsolidation processes and – if successful – their transient nature.

The activational and organizational hormone effects as originally defined do not conflict with activational influences on brain structure. Ovarian hormonal influences on the rodent corpus callosum could be activational rather than organizational. The masculinization/feminization distinction in brain structure and the timing of sex differences in visuo-spatial abilities need to be clarified.

Given Heyes's construal of “theory of mind,” there is still no convincing evidence of theory of mind in human primates, much less nonhuman. Rather than making unfounded assumptions about what underlies human social competence, one should ask what mechanisms other primates have and then inquire whether more sophisticated elaborations of those might not account for much of human competence.

Selection on grandparental investment is more complex than Coall & Hertwig (C&H) propose. Patterns of investment are subject to an intergenerational conflict over how resources should be distributed to maximize fitness. Grandparents may be selected to distribute resources unevenly, while their descendants will be selected to manipulate investment in their own favor. Here we outline the evolutionary basis of this conflict.

The colic cry as a signal of undifferentiated vigour, and not a disease, is good news. This hypothesis also has neurobiological perspectives. Feeding increases the pain threshold of the infant and has an effect on its brain functions. These may contribute, by neurobiological mechanisms, to the gradual decline in the tendency for excessive crying during the first months of life.

In this commentary, we question (1) how embodied Thelen et al.'s model is relative to their aims, and (2) how embodied the behavior of children is in particular response systems, relative to how much dynamic systems theory emphasizes this idea. We close with corrections to mischaracterizations of an alternative, neural network perspective on infant behavior.

Studies of human performance indicate that extraverts show enhanced motivation in relation to reward signals, but not in relation to safety signals under defensive conditions. When it occurs under defensive conditions, enhanced motivation may be related to neuroticism. While extraverts show some attentional skills consistent with frontal dopaminergic facilitation, other frontal capacities may be related to conscientiousness. These findings suggest that dopaminergic influences on response and attentional processes may contribute to additional personality dimensions such as neuroticism and conscientiousness.

I discuss several problems with Stanovich & West's research and suggest an alternative way to frame the rationality debate. The debate is about whether analytic (System 2) thinking is superior to intuitive (System 1) thinking or whether the two modes are complementary. I suggest that the System 1/System 2 distinction is equivalent to the Chinese concepts of yin and yang and that the two modes are complementary.

We propose that in addition to children's requests for word names being a reflection of an understanding of the referential nature of words, they may also be requests for adult's teaching. These possible requests for teaching among toddlers, along with other indications, suggest that teaching may be a natural cognition that may be related to the development of theory of mind.