Ramdohr, more than a century ago (_Venus Urania_, 1798), referred to the frequent love of little boys for women.
More usually the love is felt towards individuals of the opposite or the same sex who are not widely different in age, though usually older.

The most comprehensive study of the matter has been made by Sanford Bell in America on a basis of as many as 2,300 cases (S.Bell, "A Preliminary Study of the Emotion of Love Between the Sexes," _American Journal Psychology_, July, 1902).
Bell finds that the presence of the emotion between three and eight years of age is shown by such actions as hugging, kissing, lifting each other, scuffling, sitting close to each other, confessions to each other and to others, talking about each other when apart, seeking each other and excluding the rest, grief at separation, giving gifts, showing special courtesies to each other, making sacrifices for each other, exhibiting jealousy.

The girls are, on the whole, more aggressive than the boys, and less anxious to keep the matter secret.

After the age of eight, the girls increase in modesty and the boys become still more secretive.

The physical sensations are not usually located in the sexual organs; erection of the penis and hyperaemia of the female sexual parts Bell regards as marking undue precocity.