Temporal Segmentation in Hand Movements of Chimpanzees (Pan troglodytes) and Comparisons with Humans

Authors

  • Jenny Kien,

    Corresponding author
    1. Fachbereich Biologie, Universität Regensburg, Regensburg, and Forschungsstelle für Humanethologie, Max-Planck-Gesellschaft, Andechs
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  • Margret Schleidt,

    1. Fachbereich Biologie, Universität Regensburg, Regensburg, and Forschungsstelle für Humanethologie, Max-Planck-Gesellschaft, Andechs
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  • Bernd Schöttner

    1. Fachbereich Biologie, Universität Regensburg, Regensburg, and Forschungsstelle für Humanethologie, Max-Planck-Gesellschaft, Andechs
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Fachbereich für Biologie, Universität Regensburg, Universitätsstraße 31, W-8400 Regensburg, F.R.G.

Abstract

Hand movement action units in chimpanzees show temporal segmentation similar to but shorter than that in humans; median durations are 0.9 s in non-repetitive behaviour and 2.4 s in repetitive behaviour (vs. 2.0 s and 3.0 s in humans: Schleidt 1988; Feldhütter et al. 1990). In neither chimpanzees nor humans does one repetition of a movement within an action unit increase the duration of the action unit; each further repetition of movements in the action unit tends to prolong it by only 0.5–1 s. Thus, in both chimpanzees and humans, there appears to be some presyntactical planning in advance in repetitive hand movements. The quantitative differences in segment length may reflect uniquely human abilities of timing or sequencing muscle contractions. These findings fit well with current hypotheses that syntactical ability in language could have evolved from motor organisation.

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