Page:An introduction to ethics.djvu/61

 the preservation of the race. They are subject to variation, and as experience grows they may be modified. Instincts contribute to the formation of experience, and in turn experience influences them. Most so-called instincts are not pure instincts. Even in the lower animals experience alters and improves instincts. Thus, chicks run and swim and dive and peck and scratch instinctively. They do not need to be taught to do any of these things. But experience may modify these instincts in special ways. "The inherited tendency of the chicks is to peck—to peck 'at anything and everything not too large,' But experience very rapidly teaches that it is pleasant to peck at some things, such as yolk of egg or cabbage-moth caterpillars, and very unpleasant to peck at others, such as cinnabar caterpillars or bits of orange peel. The tendency to peck at the one sort of object is accordingly confirmed. The tendency to peck at others is inhibited. ... The instinctive tendency is regulated, narrowed, and defined, as it becomes a habit in which experience has played its part."

§2. Some Prominent Human Instincts. If we take instinct in a narrow sense, to include only those modes of behaviour which occur in a fixed and uniform way at or near the beginning of infant life, our list of human instincts will be very short. The child instinctively clasps anything placed in its hand, it instinctively sucks the breast, and instinctively crawls. The infant also expresses itself instinctively by making vocal sounds and by smiling and frowning. But if we extend the