Response to: Rethinking human development and the shared intentionality hypothesis

I respond to Moll, Nichols, and Mackey’s review of my book Becoming Human. I agree with many of their points, but have my own point of view on some others

The ultra-social animal

In evolutionary perspective, what is most remarkable about human sociality is its many and diverse forms of cooperation. Here, I provide an overview of some recent research, mostly from our laboratory, comparing human children with their nearest living relatives, the great apes, in various tests of collaboration, prosocial behavior, conformity, and group-mindedness (e.g., following and enforcing social norms). This is done in the context of a hypothetical evolutionary scenario comprising two ordered steps: a first step in which early humans began collaborating with others in unique ways in their everyday foraging and a second step in which modern humans began forming cultural groups. Humans' unique forms of sociality help to explain their unique forms of cognition and morality. © 2014. The Authors. European Journal of Social Psychology published by John Wiley & Sons, Ltd

A strategy for the design of skyrmion racetrack memories

Magnetic storage based on racetrack memory is very promising for the design of ultra-dense, low-cost and low-power storage technology. Information can be coded in a magnetic region between two domain walls or, as predicted recently, in topological magnetic objects known as skyrmions. Here, we show the technological advantages and limitations of using Bloch and Neel skyrmions manipulated by spin current generated within the ferromagnet or via the spin-Hall effect arising from a non-magnetic heavy metal underlayer. We found that the Neel skyrmion moved by the spin-Hall effect is a very promising strategy for technological implementation of the next generation of skyrmion racetrack memories (zero field, high thermal stability, and ultra-dense storage). We employed micromagnetics reinforced with an analytical formulation of skyrmion dynamics that we developed from the Thiele equation. We identified that the excitation, at high currents, of a breathing mode of the skyrmion limits the maximal velocity of the memory

Conformity to peer pressure in preschool children

Both adults and adolescents often conform their behavior and opinions to peer groups, even when they themselves know better. The current study investigated this phenomenon in 24 groups of 4 children between 4;2 and 4;9 years of age. Children often made their judgments conform to those of 3 peers, who had made obviously erroneous but unanimous public judgments right before them. A follow-up study with 18 groups of 4 children between 4;0 and 4;6 years of age revealed that children did not change their “real” judgment of the situation, but only their public expression of it. Preschool children are subject to peer pressure, indicating sensitivity to peers as a primary social reference group already during the preschool years

Chimpanzees (Pan troglodytes) coordinate by communicating in a collaborative problem-solving task

Successful collaboration often relies on individuals' capacity to communicate with each other. Despite extensive research on chimpanzee communication, there is little evidence that chimpanzees are capable, without extensive human training, of regulating collaborative activities via communication. This study investigated whether pairs of chimpanzees were capable of communicating to ensure coordination during collaborative problem-solving. The chimpanzee pairs needed two tools to extract fruits from an apparatus. The communicator in each pair could see the location of the tools (hidden in one of two boxes), whereas only the recipient could open the boxes. The subjects were first successfully tested for their capacity to understand the pointing gestures of a human who indicated the location of the tools. In a subsequent conspecifics test, the communicator increasingly communicated the tools’ location, by approaching the baited box and giving the key needed to open it to the recipients. The recipient used these signals and obtained the tools, transferring one of the tools to the communicator so that the pair could collaborate in obtaining the fruits. The study suggests that chimpanzees have the necessary socio-cognitive skills to naturally develop a simple communicative strategy to ensure coordination in a collaborative task

Prelinguistic infants, but not chimpanzees, communicate about absent entities

One of the defining features of human language is displacement, the ability to make reference to absent entities. Here we show that prelinguistic, 12-month-old infants already can use a nonverbal pointing gesture to make reference to absent entities. We also show that chimpanzees—who can point for things they want humans to give them—do not point to refer to absent entities in the same way. These results demonstrate that the ability to communicate about absent but mutually known entities depends not on language, but rather on deeper social-cognitive skills that make acts of linguistic reference possible in the first place. These nonlinguistic skills for displaced reference emerged apparently only after humans' divergence from great apes some 6 million years ago