In America, children begin pre-school at age 3. They do not officially begin Kindergarten until they are 5 years old. I think it has to do with physical and social maturity more than learning ability. I don't know how old your son is but I think Kinder for a 3 year old is too young. Our Kindergarteners are expected to know their Letters and their Sounds, Colors, Shapes, and Numbers.

In China, most kids go to kindergarden at the age of 3, nowdays more kids go there eailier, some go there in 2 years old, My son is 2.5years old, I am considering if send him to kinder. now.

Australian children can start kindergarten at 3 years old. Some go for 1/2 a day , others go for the whole day. They bring lunch and snacks for a whole day. They do activities like painting, playing with play dough, doing puzzles, walks, excursions, being told stories, playing with others. There are also 4 year old kindergartens. Ask your local kindergartens what programs they have in place. Advantages= children learn to socialize with other children, take their turn and share toys etc. Unless the staff are poorly trained or your child is physically or mentally handicapped, there are no disadvantages.

for me, i joined y first kindergarden since i was 3 years old. cuz i was very smart then lool . but it's true