Differences in efficiency of workers may be easily observed on every hand. Sometimes these differences exist in the workers themselves. Two men working side by side at similar tasks often produce unequally. One is alert and nimble; the other, sluggish and awkward. One takes pride in his work, the other grumbles at his lot and watches the clock. Each is the creature of birth, training, and habit. Industrial efficiency varies also from place to place among workers of equal ability. One manufacturing plant, for example, provides recreation grounds, rest rooms, lighted workshops, and sanitary surroundings. Here workers, other conditions being the same, can produce more than can an equal number in a plant less well equipped. Differences among peoples also play an important part in efficiency. A Chinese coolie is no match for an American laborer. One is listless, uneducated, and small of stature; the other, directly opposite in every detail. In China it is a common sight to see four or five men lifting a load which one man in this country could lift with ease.