We see culture as a system of socially transmitted patterns of behavior, preferences, and products of animal activities that characterize a group of social animals. The transmitted behaviors can be skills, practices, habits, beliefs, and so on. Once we have defined culture in this way, "cultural evolution" can be defined as the change, through time, in the nature and frequency of socially transmitted preferences, patterns, or products of behavior in a population.#2479•
What is true for rabbits also seems to be true for humans (figure 5.3). It has been found that the six-month-old babies of women who had had a lot of carrot juice during the last three months of pregnancy preferred cereal made with carrot juice to that made with water#2478•
The amniotic fluid, placenta, and milk do more than provide food materials—they also transmit information in the form of traces of the substances that the mother has eaten. This information helps to determine the preferences that become evident in the eating habits and culinary culture of the next generation.#2480•
Like learning that is mediated by the transfer of behavior-affecting substances, early social learning is usually rapid and has long-term effects. The habits acquired early in life are often hard to change, and some behaviors that are learned very easily while young are much more difficult to acquire when older.
There seems to be a special "window of learning" for some types of behavior—a window that is wide open early in life and gradually closes as the individual matures.
The learning that takes place during this circumscribed period early in life is known as "behavioral imprinting," because learning is so rapid and the behavior is so stable that it seems as if the stimuli that induce it leave a persistent "imprint" on the youngster's brain.#2472•