The erections that are liable to occur in male infants have usually no sexual significance, though, as Moll remarks, they may acquire it by attracting the child's attention; they are merely reflex. It is believed by some, however, and notably by Freud, that certain manifestations of infant activity, especially thumb-sucking, are of sexual causation, and that the sexual impulse constantly manifests itself at a very early age. The belief that the sexual instinct is absent in childhood, Freud regards as a serious error, so easy to correct by observation that he wonders how it can have arisen. "In reality," he remarks, "the new-born infant brings sexuality with it into the world, sexual sensations accompany it through the days of lactation and childhood, and very few children can fail to experience sexual activities and feelings before the period of puberty" (Freud, "Zur Sexuellen Aufklärung der Kinder," _Soziale Medizin und Hygiene_, Bd. ii, 1907; cf., for details, the same author's _Drei Abhandlungen zur Sexualtheorie_, 1905). Moll, on the other hand, considers that Freud's views on sexuality in infancy are exaggerations which must be decisively rejected, though he admits that it is difficult, if not impossible, to differentiate the feelings in childhood (Moll, _Das Sexualleben des Kindes_, p. 154). Moll believes also that psycho-sexual manifestations appearing after the age of eight are not pathological; children who are weakly or of bad heredity are not seldom sexually precocious, but, on the other hand, Moll has known children of eight or nine with strongly developed sexual impulses, who yet become finely developed men.