A SENSITIVE PERIOD FOR LEARNING ABOUT FOOD

It is proposed here that there is a sensitive period in the first two to three years of life during which humans acquire a basic knowledge o f what foods are safe to eat. In support of this, it is shown that wil lingness to eat a wide variety of foods is greatest between the ages o f one and two years, and then declines to low levels by age four. Thes e data also show that children who are introduced to solids unusually late have a narrower diet breadth throughout childhood, perhaps becaus e the duration of the sensitive period has been shortened. By reducing the costs associated with learning, a sensitive period for food learn ing should be adaptive for any omnivore (including early humans) that remains in the same environment throughout its life.