The main body of the thesis deals with selected factors underlying the considerable variability in human olfactory abilities and some odour awareness-related measures, addressed in samples ranging in age from middle childhood to young adulthood. The thesis consists of two parts. The first part (Chapter 1), first presents the major advances and developments that brought about something of a renaissance of scientific interest in the human sense of smell, including the recent proliferation of psychophysical studies, both basic research and clinical. Next, an outline of olfactory psychophysical measures and related olfactory abilities that are of relevance to the studies presented in this thesis is provided. Subsequently, the selected factors contributing to interindividual differences in olfactory abilities, that have been addressed by this thesis, are reviewed, namely the effect of sex (or gender), which is approached from a developmental perspective, childhood gender nonconformity, and personality. Finally, intraindividual fluctuations in olfactory performance are also mentioned in brief. Next, the focus shifts to odour awareness by first introducing the various approaches that can be adopted to get closer to the real-life context as opposed to laboratory setting (where most olfactory studies continue to be...