Language — the most distinctive human trait — remains a ‘mystery’1 or even a ‘problem’2 for evolutionary theory. It is underpinned by cooperative turn-taking3, which has been implicated with highly sophisticated cognitive skills such as mindreading4. Some have claimed that this turn-taking system is uniquely human5,6, but others argue that it provides the evolutionary ‘missing link’ between animal and human communication7. This debate has been constrained by a lack of comparative data, methodological confounds that often prevent meaningful comparisons, and a lack of information on key components of social relationships8,9 that might strongly impact upon turn-taking propensities. Objectives. TURNTAKING will quantify turn-taking production and comprehension in human children, chimpanzees, and two distantly related species — geladas and common marmosets. It will apply a powerful combination of systematic behavioral observations, eye-tracking paradigms, and established measures from Conversational Analysis3,10 and Primatology9 that allow the same type of data to be collected and analyzed in directly comparable ways across species. This will provide the first rigorous test of whether cooperative turn-taking is uniquely human, ancestral in the primate lineage, or evolved independently in different species. TURNTAKING will identify which hallmarks of human turn-taking are shared across different primate species, and which key components of relationship quality8,9 act upon turn-taking skills. Outcomes. This project will found the field of comparative turn-taking, and provide pioneering insights into the behavioral flexibility underlying different turn-taking systems. It will go beyond the state of the art by exposing whether cooperative turn-taking is the evolutionary ‘missing link’ between our species and our inarticulate primate cousins, and whether pro-social behaviors drove its emergence.

Aim of the proposed project is a) development and establishment of insect-inspired capillary nanostamping (IICN) as next-generation contact nanolithography, b) replacing state-of-the-art lithographic and synthesis protocols requiring use of sacrificial templates or time-consuming self-assembly steps by IICN and c) significant IICN-driven acceleration and upscaling of the production of extended nanostructured systems. To meet these aims, IICN stamp design will be inspired by insect feet depositing small secretion droplets through arrays of hairy contact elements on counterpart surfaces. Monolithic IICN stamps extending cm2 will consist of spongy ink-filled substrates connected to extended arrays of spongy nanoscale dispensing elements with diameters in the 100 nm range (density up to ~130 dispensing elements per square micron). Ink supplied through the spongy pore systems forms capillary bridges between each dispensing element and counterpart surfaces, thus enabling massively parallel capillary bridge-guided nanorod synthesis. Capillary bridge rupture during stamp retraction leads to massively parallel lithographic deposition of ink nanodroplet arrays (target nanodroplet volume: a few 10 zeptolitres). IICN model applications include production of a) ultrathin nanoporous membranes for separation; b) ordered silicon nanostructures by IICN-supported metal-assisted etching; c) nearly-ergodic arrays of encapsulated liquid nanocontainers for massively parallel ensemble nanochemistry or ensemble tracing of single molecules; d) nearly-ergodic biochips for massively parallel analyte detection with single-molecule resolution. As example for substitution of time-consuming self-assembly in nanomaterial synthesis by IICN, IICN-accelerated production of ordered nanoporous alumina will be studied. To pave the way for upscaling and potential commercialization of IICN, high-throughput IICN devices for automated operation in batch and continuous roller modes will be constructed.