In conclusion it can be stated that Cruse & Schilling (this collection) present a highly fascinating research strategy that is well worth pursuing. The bottom-up approach can provide us with new insights regarding the functional mechanisms underlying psychological phenomena and their evolution. Although the notion of emergence is central to it, Cruse & Schilling (this collection) avoid the philosophical controversies surrounding this concept by interpreting it in a less demanding, yet interesting and useful way. There are, however, a number of constraints that explanations based on the bottom-up approach have to meet. First, since Cruse & Schilling’s (this collection) strategy involves, at two points, a comparison between markedly different systems, criteria are needed according to which we can determine whether the two systems exhibit relevantly similar behaviour. Second, the structural architecture of the artificial system must have an adequate degree of biological plausibility. And finally, it has to be ensured that increasing the complexity of the system does not lead to the practical impossibility of elucidating the mechanisms underlying its emergent properties.
A promising next step for bottom-up research as presented by Cruse & Schilling (this collection) would be to take it to the level of social interaction. An extensive social extension of their system could shed light on a wide range of intriguing phenomena. Is it possible to discover emergent properties on a group level? In what precise way are mirroring mechanisms involved in social cognition? What role do such mechanisms play for the phenomenon of self-consciousness? What role do reactive structures and internal body-models play in the processes of language acquisition and comprehension? Of course this is only a small selection of the questions further bio-robotic research might contribute to answering. Cruse & Schilling (this collection) made clear that starting from the bottom is a strategy with enormous scientific significance. There is no doubt that this work will make an important contribution to a plethora of research projects in the future.