In a suggestive statistical study on the relations of the conduct of children to the weather, Dexter[7] found that excessive humidity was most productive of misdemeanors; that when the temperature was between 90 and 100 the probability of bad conduct was increased 300 per cent, when between 80 and 90 it was increased 104 per cent. Abnormal barometric pressure, whether great or small, was found to increase misconduct 50 per cent; abnormal movements of the wind increased it from 20 to 66 per cent; while the time of year and precipitation seemed to have almost no effect. While the effect of weather has been generally recognized by superintendents and teachers and directors of prisons and asylums, and even by banks, which in London do not permit clerks to do the more important bookkeeping during very foggy days, the statistical estimates of its effect in general need larger numbers for more valuable determinations. Temperature is known to have a very distinct effect upon crime, especially suicide and truancy. Workmen do less in bad weather, blood pressure is modified, etc.[8]
In his study of truancy, Kline[9] starts with the assumption that the maximum metabolism is always consciously or unconsciously sought, and that migrations are generally away from the extremes of hot and cold toward an optimum temperature. The curve of truancies and runaways increases in a marked ratio at puberty, which probably represents the age of natural majority among primitive people. Dislike of school, the passion for out-of-door life, and more universal interests in man and nature now arise, so that runaways may be interpreted as an instinctive rebellion against limitations of freedom and unnatural methods of education as well as against poor homes. Hunger is one of its most potent, although often unconscious causes. The habitual environment now begins to seem dull and there is a great increase in impatience at restraint. Sometimes there is a mania for simply going away and enjoying the liberty of nomadic life. Just as good people in foreign parts sometimes allow themselves unwonted liberties, so vagrancy increases crime. The passion to get to and play at or in the water is often strangely dominant. It seems so fine out of doors, especially in the spring, and the woods and fields make it so hard to voluntarily incarcerate oneself in the schoolroom, that pubescent boys and even girls often feel like animals in captivity. They long intensely for the utter abandon of a wilder life, and very characteristic is the frequent discarding of foot and head dress and even garments in the blind instinct to realise again the conditions of primitive man. The manifestations of this impulse, if read aright, are grave arraignments of the lack of adaptability of the child's environment to his disposition and nature, and with home restraints once broken, the liabilities to every crime, especially theft, are enormously increased. The truant, although a cording to Kline's measurements slightly smaller than the average child, is more energetic and is generally capable of the greatest activity and usefulness in more out-of-door vocations. Truancy is augmented, too, just in proportion as legitimate and interesting physical exercise is denied.