Notwithstanding the general tendency for crime to reach its maximum in the first hot month (a tendency not necessarily due to the direct influence of heat), we also find, when we consider the statistics of crime generally (including sexual crime), that there is another tendency for minor climaxes in spring and autumn. Thus, in Italy, Penta, taking the statistics of nearly four thousand crimes (murder, highway robbery, and sexual offences), found the maximum in the first summer months, but there were also minor climaxes in spring and in August and September (Penta, Rivista Mensile di Psichiatria, 1899). In nearly all Europe (as is shown by a diagram given by Lombroso and Laschi, at the end of the first volume of Le Crime Politique), while the chief climaxes occur about July, there is, in most countries, a distinct tendency to spring (usually about March) and autumn (September and November) climaxes, though they rarely rise as high as the July climax.
If we consider the separate periodicity of sexual offences, we find that they follow the rule for crimes generally, and usually show a chief maximum in early summer. Aschaffenburg finds that the annual periodicity of the sexual impulse appears more strongly marked the more abnormal its manifestations, which he places in the following order of increasing periodicity: conceptions in marriage, conceptions out of marriage, offences against decency, rape, assaults on children (Centralblatt für Nervenheilkunde, January, 1903). In France, rapes and offences against modesty are most numerous in May, June, and July, as Villermé, Lacassagne, and others have shown. Villermé, investigating 1,000 such cases, found a gradual ascent in frequency (only slightly broken in March) to a maximum in June (oscillating between May and July, when the years are considered separately), and then a gradual descent to a minimum in December. Legludic gives, for the 159 cases he had investigated, a table showing a small February-March climax, and a large June-August maximum, the minimum being reached in November-January. (Legludic, Attentats aux Mœurs, 1896, p. 16.) In Germany, Aschaffenburg finds that sexual offences begin to increase in March and April, reach a maximum in June or July, and fall to a minimum in winter (Monatsschrift für Psychiatrie, 1903, Heft 2). In Italy, Penta shows that sexual offences reach a minor climax in May (corresponding, in his experience, with the maximum for crimes generally, as well as with the maximum for conceptions), and a more marked climax in August-September (Penta, I Pervertimenti Sessuali, 1893, p. 115; id. Rivista Mensile di Psichiatria, 1899).
Corre, in his Crime en Pays Créole, presents charts of the seasonal distribution of crime in Guadeloupe, with relation to temperature, which show that while, in a mild temperature like that of France and England, crime attains its maximum in the hot season, it is not so in a more tropical climate; in July, when in Guadeloupe the heat attains its maximum degree, crime of all kinds falls suddenly to a very low minimum. Even in the United States, where the summer heat is often excessive, it tends to produce a diminution of crime.
Dexter, in an elaborate study of the relationship of conduct to the weather, shows that in the United States assaults present the maximum of frequency in April and October, with a decrease during the summer and the winter. "The unusual and interesting fact demonstrated here with a certainty that cannot be doubted is," he concludes, "that the unseasonably hot days of spring and autumn are the pugnacious ones, even though the actual heat be much less than for summer. We might infer from this that conditions of heat, up to a certain extent, are vitalizing, while, at the same time, irritating, but above that limit, heat is so devitalizing in its effects as to leave hardly energy enough to carry on a fight." (E. G. Dexter, Conduct and the Weather, 1899, pp. 63 et seq.)
It is not impossible that the phenomena of seasonal periodicity in crimes may possess a real significance in relation to sexual periodicity. If, as is possible, the occurrence of spring and autumn climaxes of criminal activity is due less to any special exciting causes at these seasons than to the depressing influences of heat and cold in summer and winter, it may appear reasonable to ask whether the spring and autumn climaxes of sexual activity are not really also largely due to a like depressing influence of extreme temperatures at the other two seasons.
Not only is there periodicity in criminal conduct, but even within the normal range of good and bad conduct seasonal periodicity may still be traced. In his Physical and Industrial Training of Criminals, H. D. Wey gives charts of the conduct of seven prisoners during several years, as shown by the marks received. These charts show that there is a very decided tendency to good behavior during summer and winter, while in spring (February, March, and April) and in autumn (August, September and October) there are very marked falls to bad conduct, each individual tending to adhere to a conduct-curve of his own. Wey does not himself appear to have noticed this seasonal periodicity. Marro, however, has investigated this question in Turin on a large scale and reaches results not very dissimilar from those shown by Wey's figures in New York. He noted the months in which over 4,000 punishments were inflicted on prisoners for assaults, insults, threatening language, etc., and shows the annual curve in Tavola VI of his Caratteri dei Delinquenti. There is a marked and isolated climax in May; a still more sudden rise leads to the chief maximum of punishment in August; and from the minimum in October there is rapid ascent during the two following months to a climax much inferior to that of May.
The seasonal periodicity of bad conduct in prisons is of interest as showing that we cannot account for psychic periodicity by invoking exclusively social causes. This theory of psychic periodicity has been seriously put forward, but has been investigated and dismissed, so far as crime in Holland is concerned, by J. R. B. de Roos, in the Transactions of the sixth Congress of Criminal Anthropology, at Turin, in 1906 (Archivio di Psichiatria fasc. 3, 1906).
The general statistics of suicides in Continental Europe show a very regular and unbroken curve, attaining a maximum in June and a minimum in December, the curve rising steadily through the first six months, sinking steadily through the last six months, but always reaching a somewhat greater height in May than in July.[[164]] Morselli shows that in various European countries there is always a rise in spring and in autumn (October or November).[[165]] Morselli attributes these spring and autumn rises to the influence of the strain of the early heat and the early cold.[[166]] In England, also, if we take a very large number of statistics, for instance, the figures for London during the twenty years between 1865 and 1884, as given by Ogle (in a paper read before the Statistical Society in 1886), we find that, although the general curve has the same maximum and minimum points, it is interrupted by a break on each side of the maximum, and these two breaks occur precisely at about March and October.[[167]] This is shown in the curve in [Chart VI], which presents the daily average for the different months.
The growth of children follows an annual rhythm. Wahl, the director of an educational establishment for homeless girls in Denmark, who investigated this question, found that the increase of weight for all the ages investigated was constantly about 33 per cent. greater in the summer half-year than in the winter half-year. It was noteworthy that even the children who had not reached school-age, and therefore could not be influenced by school-life, showed a similar, though slighter, difference in the same direction. It is, however, Malling-Hansen, the director of an institution for deaf-mutes in Copenhagen, who has most thoroughly investigated this matter over a great many years. He finds that there are three periods of growth throughout the year, marked off in a fairly sharp manner, and that during each of these periods the growth in weight and height shows constant characteristics. From about the end of November up to about the end of March is a period when growth, both in height and weight, proceeds at a medium rate, reaching neither a maximum nor a minimum; increase in weight is slight, the increase in height, although trifling, preponderating. After this follows a period during which the children show a marked increase in height, while increase in weight is reduced to a minimum. The children constantly lose in weight during this period of growth in height almost as much as they gain in the preceding period. This period lasts from March and April to July and August. Then follows the third period, which continues until November and December. During this period increase in height is very slight, being at its early minimum; increase in weight, on the other hand, at the beginning of the period (in September and October), is rapid and to the middle of December very considerable, daily increase in weight being three times as great as during the winter months. Thus it may be said that the spring sexual climax corresponds, roughly, with growth in height and arrest of growth in weight, while the autumn climax corresponds roughly with a period of growth in weight and arrest of growth in height. Malling-Hansen found that slight variations in the growth of the children were often dependent on changes in temperature, in such a way that a rise of temperature, even lasting for only a few days, caused an increase of growth, and a fall of temperature a decrease in growth. At Halle, Schmid-Monnard found that nearly all growth in weight took place in the second half of the year, and that the holidays made little difference. In America, Peckham has shown that increase of growth is chiefly from the 1st of May to the 1st of September.[[168]] Among young girls in St. Petersburg, Jenjko found that increase in weight takes place in summer. Goepel found that increase in height takes place mostly during the first eight months of the year, reaching a maximum in August, declining during the autumn and winter, in February being nil, while in March there is sometimes loss in weight even in healthy children.