Development of odour awareness in pre-schoolers: A longitudinal study

Conducting interviews about children's olfactory behaviours offers a feasible way of learning about the earliest perceptions and knowledge of one's odour world. However, little is known about the stability and development of such self-reports. Here we present the first longitudinal study to repeatedly test children's odour awareness using the Children's Olfactory Behavior in Everyday Life (COBEL) questionnaire in five waves over a two-year period. We expected that higher scores would be attained by girls relative to boys and by older children compared to younger ones and that the scores would increase further into the study. We found a linear time-related increase in the total COBEL scores and in the food and environmental components, whereas awareness of social odours decreased over time. Girls were more olfaction-oriented in the context of social and environmental, but not food, odours. All the reported effects were small. The age at which the children entered the study did not affect their scores. We suggest that the unexpected findings regarding social odours warrant replication in particular and extension in longitudinal studies carried out over a broader time span.