Touch is the earliest sense to mature. It manifests itself in the final embryonic stage and comes into its own long before eyes, ears, and the higher brain centers begin to work. Soon ＿＿（41）＿＿ birth, infants begin to employ their other senses to interpret reality. During the same period, they are highly ＿＿（42）＿＿ touch. They are being nuzzled, cuddled, cleaned, patted, kissed, and in many cases breastfed. So important is touch to human communication ＿＿（43）＿＿ researchers now know that people who are denied caregivers' touch can develop serious biological and emotional problems. As you move from infancy into childhood, you learn the rules of touching. You are taught whom to touch and where they may be touched. By the time you reach ＿＿（44）＿＿ , your culture has taught you how to communicate with touch. You use touch out of social politeness, ＿＿（45）＿＿ sex, consolation, support, and control. In the U.S., people learn to shake hands with nearly everyone, hug certain people, and be intimate with still other people.