Having listed the native tendencies generally, we might well now consider them as they manifest themselves at the various stages of an individual's development. As already indicated, they constitute his birthright as a human being, though most of them are present in the early years of his life only in potentiality. Psychologists of recent years have made extensive observations as to what instincts are most prominent at given periods. Teachers are referred particularly to the volumes of Kirkpatrick, Harrison, and Norsworthy and Whitley. In this latter book, pages 286, 287, and 298-302, will be found an interesting tabulation of characteristics at the age of five and at eleven. For the years of adolescence Professor Beeley, in his course at the Brigham Young Summer School, in the Psychology of Adolescence, worked out very fully the characteristics unique in this period, though many of them, of course, are present at other stages: CHARACTERISTICS UNIQUE IN THE ADOLESCENT PERIOD 1. Maturing of the sex instincts. 2. Rapid limb growth. 3. Over-awkwardness. 4. Visceral organs develop rapidly (heart, liver, lungs, genital organs.) 5. Change in physical proportions; features take on definite characteristics. 6. Brain structure has matured. 7. Self-awareness. 8. Personal pride and desire for social approval. 9. Egotism. 10. Unstable, "hair-trigger," conflicting emotions. 11. Altruism, sincere interest in the well-being of others. 12. Religious and moral awakening. 13. New attitude. 14. Aesthetic awakening. 15. Puzzle to everybody. 16. Desire to abandon conventionalities, struggle for self-assertion. 17. Career motive. 18. Period of "palling" and mating; clique and "gang" spirit. 19. Positiveness,--affirmation, denial. 20. Inordinate desire for excessive amusement. 21. Evidence of hereditary influences. 22. "Hero worship," castle building. 23. "Wanderlust." 24. Hyper-suggestibility. 25. Ideals; ambitions. 27. Yearning for adult responsibility. Having listed these tendencies we still face the question, "What shall we do with them? What is their significance in teaching?" It is perfectly clear, in the first place, that we ought not to ignore them. None of them is wholly useless, and few of them can safely be developed just as they first manifest themselves. They call for training and direction. "Some instincts are to be cherished almost as they are; some rooted out by withholding stimuli, or by making their exercise result in pain or discomfort, or by substituting desirable habits in their place; most of the instincts should be modified and redirected."--(_Thorndike._) Our concern as teachers ought to be that in our work with boys and girls, men and women, we are aware of these natural tendencies that we may work with them rather than contrary to them--that we may "follow the grain" of human nature.