"...a 'standard' age to begin..."
It might work at the same age as you can begin to teach them some musical instrument. Which is about 5 -6 years. With the musical instrument it worked for my daughter (27 years now). With chess it didn't work. With my son (24 years now): no success. No chess and no music. OK, now he begins to play chess. In other words: it depends. Please take this nice picture as an inspiration: http://65.media.tumblr.com/tumblr_m1owh6WJgM1rru2i6o1_500.jpg More than words. You need to play with them :-) The violinist on the picture is Henryk Szeryng. See also en.wikipedia.org/wiki/Henryk_Szeryng
Best regards and have fun with your son, Karl
It might work at the same age as you can begin to teach them some musical instrument. Which is about 5 -6 years. With the musical instrument it worked for my daughter (27 years now). With chess it didn't work. With my son (24 years now): no success. No chess and no music. OK, now he begins to play chess. In other words: it depends. Please take this nice picture as an inspiration: http://65.media.tumblr.com/tumblr_m1owh6WJgM1rru2i6o1_500.jpg More than words. You need to play with them :-) The violinist on the picture is Henryk Szeryng. See also en.wikipedia.org/wiki/Henryk_Szeryng
Best regards and have fun with your son, Karl