Synaesthesia is a neurodevelopmental condition characterised by anomalous sensory perceptions and associated alterations in cognitive function. This chapter summarises what is known about the familial transmission of synaesthesia and its genetic underpinnings. Early familiality studies showed evidence for a strong genetic predisposition, a highly skewed female: male ratio, and an absence of male-to-male transmission. These patterns supported an early hypothesis of a single-gene X-linked dominant mode of inheritance with male lethality. Subsequent analyses in larger samples indicated that the mode of (...) inheritance was likely to be more complex, with both the strong female skew and absence of male-to-male transmission brought into question. We review in detail the first whole genome linkage scan for auditory-visual synaesthesia and a subsequent family linkage study on coloured sequence synaesthesia. Together these results suggest linkage to five chromosomes but give no support for linkage to the X-chromosome. We discuss candidate genes within these regions and potential implications for the aetiology of synaesthesia. We also discuss the implications of these pioneering genome scans for our understanding of synaesthesia and of how different synaesthetic phenotypes may arise from different genetic predispositions interacting with other genes and with the environment. (shrink)

Hobbes’ account of these issues is conspicuously brief and puzzling. Indeed it has been criticized by some commentators as ‘confused.’ I hope to show, however, that it appears confused only because it has not been read with sufficient precision. Properly understood, Hobbes’ account is both exact and profound. It is also, in my view, far more interesting as a conception of natural right than the modern ‘confusions’ which have come to be read into it.To show this, the text must be (...) read as it is presented: on its own terms, analytically and exactly. In what follows, therefore, I shall focus upon Hobbes’ definitive account of the right of nature in chapter XIV of Leviathan, with only minimal reference to other passages and other works. I do not pretend that this is the only possible approach to Hobbes on this point; but it does show how his account may be read intelligibly, and with greater respect for the power and precision of his thought. (shrink)