But to have a large surplus of vital energy implies a good organization, which is on the average of cases likely to last long. So that, in fact, the superiority of physique which is accompanied by strength of the instincts and emotions causing marriage is a superiority of physique also conducive to longevity.
One further influence tells in the same direction. Marriage is not altogether determined by the desires of men; it is determined in part by the preferences of women. Other things equal, women are attracted toward men of power physical, emotional, intellectual; and obviously their freedom of choice leads them in many cases to refuse inferior samples of men; especially the malformed, the diseased, and those who are ill-developed, physically and mentally. So that, in so far as marriage is determined by female selection, the average result on men is that, while the best easily get wives, a certain proportion of the worst are left without wives. This influence, therefore, joins in bringing into the ranks of married men those most likely to be long-lived, and keeping in bachelorhood those least likely to be long-lived.
In three ways, then, does that superiority of organization which conduces to long life also conduce to marriage. It is normally accompanied by a predominance of the instincts and emotions prompting marriage; there goes along with, it that power which can secure the means of making marriage practicable; and it increases the probability of success in courtship. The figures given afford no proof that marriage and longevity are cause and consequence; but they simply verify the inference which might be drawn a priori, that marriage and longevity are concomitant results of the same cause.
This striking instance of the way in which inference may be mistaken for fact, will sufficiently serve as a warning against another of the dangers that await us in dealing with sociological data. Statistics having shown that married men live longer than single men, it seems an irresistible implication that married life is healthier than single life. And yet we see that the implication is not at all irresistible: though such a connection may exist, it is not demonstrated by the evidence assigned. Judge, then, how difficult it must be, among those social phenomena where the dependencies are more entangled, to distinguish between the seeming relations and the real relations.
Once more, we are ever liable to be led away by superficial, trivial facts, from those deep-seated and really important facts which they indicate. Always the small details of social life, the interesting events, the curious things which serve for gossip, will, if we allow them, hide from us the vital connections and the vital actions underneath. Every social phenomenon results from an immense aggregate of general and special causes; and we may either take the phenomenon itself as intrinsically momentous, or, along with other phenomena, may take it as indicating some inconspicuous truth of real significance. Let us contrast the two courses.