What did people think of children's artwork before modern art?

One of the most interesting aspects of this topic is that there is hardly any mention of children's art at all before the 19th century. To some extent this isn't surprising because the idea of childhood as a separate state from adulthood only emerges (in writing, anyway) during the 18th century. And only with the Romantics do we see an understanding of art that moves away from conventional, representational modes of art making, and that can acknowledge other forms of visual art as manifestations of creativity. Swiss artist and educator Rudolphe Toppfer wrote an essay in the 1830s with an innovative conception of children's art for the time: "I have seen, and you also, that most of these works [of children], all wrong and messily drawn as they are, still vividly reflect, besides imitative intention, an intention of thought, in such a way that the thought is all the more evident that because of the graphic ignorance of the designer. Although we only see parts which are hardly recognizable, considered one by one: a surprising face, a frame badly built, and two sticks for legs, we understand, nevertheless, the signs of vitality, the suggestions of expression, the symptoms of order and unity, signs above all of a creative freedom which prevails far above servitude to imitation in works of art." By the end of the 19th century, psychologists and educators such as Carrado Ricci were writing seriously about the children's art. To some extent the fact that we regard children's art as art is due to modern artists being inspired by it.  20th-century artists including Paul Klee, Pablo Picasso, Wassily Kandinsky, and Jean Dubuffet all looked to children's art for inspiration. Kandinsky wrote in 1912: "in every child's drawing, without exception, the inner sound of the object exposes itself spontaneously...." In the 1960s, Picasso said to his critic Harry Read after viewing an exhibition of children's art in Paris: "When I was the age of these children, I could paint like Raphael. It took me many years to learn how to paint like these children." This answer is largely derived from an article by Jo Alice Leeds, "History of Attitudes towards Children's Art" Studies in Art Education vol 30, no. 2 (1989), pp. 93-103.

At least one Renaissance artist thought it was cool. "Portrait of a Young Boy holding a Child’s Drawing" by Giovanni Francesco Caroto (about 1480–about 1555), c.1515. © Museo di Castelvecchio, Verona (5519-1B0130). Photo Umberto Tomba. © Museo di Castelvecchio, Verona (5519-1B0130). Photo Umberto Tomba.

I think it might have something to do with how we define "art". Before 1920, we have very strictly definition about what art is. It is a skill, a craft, people get professionally trained, go through often rigid steps/apprenticeship to learn to paint, to sculpt, to create. In Renaissance, painter and sculptor were craftsman, same as carpenter, glass worker, and metalworker. Art wasn't treated as an natural part of human being until early 20th century. In short, good at art wasn't something as glorious as we consider it now. It's not something people would encourage their children to do (unless the parents are also craftsman), and not something parents would be proud of their children. Art wasn't about emotion in the old times, art is more about narrative. Portraits, religious murals, even landscape and still life, they all have some kind of story to tell. And to tell a story, to communicate to your audience clearly and effectively, you need training. That's what we used to see art. A narrative art form. But Impressionism changed that. And art moved away from narrative to more emotional charged and conceptual. That's when children's art become "art", since children are pure emotion. They don't care about skill or whatever, I think many modern artists really want to get to that state of mind, to express their pure emotion. Overall, I think people don't think much about Children's art before modern time. And I think children's art is overrated now.

do you recall a thing called "child labor" - with such level of "respect" towards the children, i think evaluation of their artwork was a non-issue..