What toys are better for 1.5 years old toddler - natural, simple, wooden, unpainted bricks or very colourful ones? Natural were recommended by Rudolf Steiner (and are used in schools teaching with his methods) and they orjust feel right, but most of today's toys are very colorful - any specific reason?
There is actually some science behind those bright colors! Babies develop eyes, but not full sight in the womb - there isn't a lot to see in there. There is quite a series of steps in their visual development in the first year of baby's life. While baby can see color from birth, distinguishing between different tones of color is pretty difficult so colors that contrast with each-other and their background are great for young kids. This is way primary colors - red, blue and yellow are seen so much in BABY toys, as well as why you see patterns with black and white.
By 1.5, kids have pretty well established vision, but as Dan Beale shares, it is all about language development and learning sorting skills. Blocks with colors and letters/numbers are GREAT for developing a child's ability to distinguish between different groups of things, label and describe what they are after, and connect skills involved with use of symbols (an important precursor to reading). That is why alphabet blocks are such a classic standard.
However, paints from the past have been hazardous, so be mindful of the quality of your purchase. I don't know what kind of safety standards coorporations in your area are held to, but you'll want to be sure that in the case of painted blocks, the paints used are safe for children (no lead based paints etc.) Non-toxic and products made with environmental considerations are generally going to cross-over, but you'll also want to consider size of blocks etc. especially if your child is still mouthing toys so be sure whatever you buy meets high quality CHILD safety standards.
I like mostly plain wooden blocks personally - they do have a nice feel to them, so if you are introducing colors and symbols in other aspects of the child's life it really is just a personal choice, and no paint (or sealer) is going to be the absolute safest way to go. At the same time, safety standards in most European countries are pretty well established (based on the little I've heard about it - I'll admit) and with research you can find good quality blocks which are painted and also perfectly safe. We had a mixture of both in our house.
Colours give more opportunity for language - "pass the blue block please!".
Bright colours are appealing to some children.
What's available tends to be good enough. There comes a point where further optimization is wasteful compared to other things you could be doing.
Variety is probably good too. So a plain set might be fun as well as all the other colourful stuff.
I suppose some children might feel overwhelmed by all the different colours, or might want to concentrate on just on colour.
I would be interested to hear if there is any real science behind bright colours for all toys.
Steiner (or Waldorf) education emphasizes imaginative play. The idea with simple toys, in this case uncolored blocks, is that it requires more from the imagination. This is right brain development. The goal is to develop creativity.
As others have pointed out, colors allow you the opportunity to use words to describe, to sort, and to build using patterns. These concepts are mostly left brain concepts (creating patterns is more of a left brain activity, while recognizing them may be right brain).
I personally would probably choose colored blocks, because I think it is quite possible for a child to build a garage or castle without really "seeing" the colors, and having colored blocks allows you to engage the left side of the brain as well with color recognition, sorting, and patterning. However, the Steiner schools have been very successful with developing creative thinkers, so there may be something to the purist approach.
Bricks are going to be used to build something, whether they are colored or not. I'd say get colorful ones, because they will allow the built things to have more details - a blue brick may be a window in a house, a black one may be a chimney, green can be grass, and so on. It gives more possibilities.
One might say that the colors will leave less to the imagination. But since the building process requires imagination anyway, I'd say this is a flawed argument.