Over the last two decades, the influence of seasonality has appeared as a central theme in human ecology. In most cases the focus has been on objective aspects: measurable biological variations such as mortality, morbidity, birth rate, growth rate and state of nutrition in relation to seasonal environmental changes (e.g. Chambers et al., 1981; Harrison, 1988, p. 27; Foeken, 1990). In human societies, these aspects are influenced by cultural choices, which are more or less attuned to optimal biological fitness. Cultural factors which have a bearing on human biology and are influenced by seasonality include lifestyle, type of production system, choices of technology, division of labour, social organisation, time schedule, habitat choice, food consumption, and aspects of material culture. However, humans are endowed with symbolic thinking, and the non-material, psychocultural (Folkman & Lazarus, 1988) and cognitive (Laughlin & Brady, 1978, pp. 1, 13) aspects of seasonality are also important. Butzer (1982, p. 255) writes ‘identification of environmental components, resource opportunities … are all intimately related to group perception’. Through culture, the material environment is grasped as a cognised environment, an ‘intentional world’ (Shweder, 1990, p. 25) endowed with meaning and calling for actions ‘on tangible as well as on non-tangible realities’ (Augé, 1986, p. 81), each society having its own local symbolic system (Stigler et al., 1990, p. VIII).

Perception of events and coping behaviour have emotional components; they are appraised as positive/good or negative/bad according to personal and cultural views.