Most of Andrew's publications in the specialist literature describe details of the lives of cephalopod molluscs (octopuses, squids and cuttlefishes). His main contribution to the Third Way was a Biological Reviews article published in 1972 outing a co-evolutionary idea: that the well documented trajectory of this formidable group of marine animals over 500 million years of fossil time was a story of close encounters with their vertebrate contemporaries in shared behaviour space. It found general acceptance amongst other teuthologists. Nevertheless the argument that the remarkable parallels between the two groups – measurable in functional anatomy, physiology, and the psychology findings emerging from the Naples Zoological Station – are both cause and consequence of that story, opens the flood gates to a still more general, and at the time heterodox, idea: that behaviour is the stable block upon which the genome – in this case the molluscan or vertebrate genome – is slipping.
An intellectual need to accommodate principles operating in other branches of science, and in the humanities – where such things may be “blindingly obvious” – has since led him to re-introduce feelings (affect) as major player in that overall space: an idea implicit in the thinking of Charles Darwin, made explicit by Suzanne Langer and in J.Z.Young's insistence on the role of choice. It belongs with the 4th Variable of John B. Cobb. There too the physiological evidence can be traced back half a billion years.
In 2011, Packard organised a meeting at the Linnean Society, London on strain-induced self-assembly and the growth of form (David Knight).