I'm basically saying it's too early to tell. Even testing at age 4 or 5 is quite unreliable, although it is said that parents' assessments are more reliable. Nevertheless, you can try to create an environment where a child can reach their potential, even if you're not sure what their potential is. (School's should try this idea too.)
I totally got that--just thought I'd respond after Thomas Percy brought up his point, too.
On your comment about schools creating environments where students can realize their full potential: my husband's area of research is in economics of education, so he might actually have some insight to things like this... (His other area of interest is health econ, which is tangentially related.)
