"There are many other activities, not so obviously vital as these, for which nature winds him up quite as thoroughly--yes, and sets him to go off at the proper time for each. He will suck when brought to the breast as unfailingly as his lungs will begin to work upon contact with the air. He will cry from hunger or discomfort, clasp anything that touches his fingers or toes, carry to his mouth whatever he can grasp, in time smile when smiled at, later grow afraid when left alone or in the dark, manifest anger and affection, walk, run, play, question, imitate, collect things, pull things apart, put them together again, take pleasure in being with friends, act shy before strangers, find a chum, belong to a 'gang' or 'bunch,' quarrel, fight, become reconciled, and some day fall in love with one of the opposite sex. These, and many more, are just his natural human ways. He does not of purpose initiate them any more than he initiates breathing or heart-beat. He does these things because he is so born and built. They are his instincts." As Norsworthy and Whitley point out, we are not especially concerned with the boundary lines between automatic actions, reflexes, and instincts--we are rather concerned with the fact that human beings possess native tendencies to act in particular ways. Some psychologists stress them as instincts; others as capacities, but they have all pretty generally agreed that under certain stimuli there are natural tendencies to react. These tendencies begin to manifest themselves at birth--they are all potentialities with the birth of the child--and continue to develop in turn, certain ones being more pronounced in the various stages of the child's life. Colvin in his _The Learning Process_, runs through the complete list of possibilities. According to him man, in a lifetime, is characterized by the following tendencies: Fear, anger, sympathy, affection, play, imitation, curiosity, acquisitiveness, constructiveness, self-assertion (leadership), self-abasement, rivalry, envy, jealousy, pugnacity, clannishness, the hunting and predatory instincts, the migratory instinct, love of adventure and the unknown, superstition, the sex instincts, which express themselves in sex-love, vanity, coquetry, modesty; and, closely allied with these, the love of nature and of solitude, and the aesthetic, the religious, and the moral emotions. Sisson, in a little book that every teacher ought to know, _The Essentials of Character_, emphasizes the importance for teaching of ten tendencies: bodily activity, sense-hunger and curiosity, suggestibility, tastes and aesthetic appreciation, self-assertion, love, joy, fear, the growing-up impulse, the love of approbation.