Olfaction

The ability to perceive volatile chemicals, or odorants, is referred to as olfaction. Olfactory ability generally improves during childhood and declines in later life, with females consistently outperforming males. Olfaction has a number of functions in humans, notably concerning eating (e.g., food choice, breastfeeding), socialization (e.g., personal hygiene, disgust), sexuality (e.g., mate choice), and hazard warnings (e.g., rotting food, smoke, gas). Many of these functions have specific relevance at certain points in development (e.g., breastfeeding in infancy, mate choice, and personal hygiene in adolescence and early adulthood) and involve some form of learning (e.g., smoke means fire, baking cakes smell good because their odor signals calories). Olfactory ability is also an early marker of certain diseases that occur at particular points in development, including schizophrenia ...