The ethological basis of certain signals of affect and emotion 1

A key assumption of ethology is that characteristic behavior of organisms is that which brings some benefit, or in the jargon, “increased fitness,” to them or their kin. Innate (geneticallydetermined) behavior has this characteristic, e.g., the broken-wing feint of different species of ground-nesting birds which draws prey away from the nest of chicks. (This is not to deny that characteristic behavior can also be socially-determined, e.g., obeying traffic laws, especially after the first penalty for not doing so). Morton (1977) has documented presumably innately determined factors which shape the vocalizations of several bird and mammal species’ in agonistic encounters (face-to-face competition). His generalizations apply equally well to certain behaviors that the human mammal also produces in agonistic situations but also, perhaps by some socially-determined extrapolation to characteristic intonations for question vs. declaration and to sound symbolic vocabulary designating small (and thus non-threatening and endearing) vs. large (threatening and impressive) entities (Ohala 1984). In this paper I review the evidence and theories underlying these connections between the sound shape and the meanings or communicative intentions conveyed by them and extend these principles to attempt to give a novel, if speculative, account of apparently similar cross-cultural use of the eyes and eyebrows in non-verbal communication where, again, the “messages” can be construed as conveying threat vs. non-threat. Two central element in this account are (1) the biological fact that the ratio of eye diameter to head diameter varies markedly with age: infants are said to have “large eyes”, in reality just a large ratio of eye diameter to head diameter, whereas in mature individuals this ratio is much smaller and (2) humans (and many other species) have the capacity to vary the apparent eye size and thus can exploit the apparent ratio of eye to head diameter for signaling emotion and affect.