Someone on a board I frequent was asking how we know if our children are working to their full potential? How we know they are as gifted as we think they are?
Here's my reply (I almost have to laugh at how calm I am about it all now that I have had a few years to adjust to Haley because just a few years ago, I agonized over the same issues.)....
I used to agonize over the same questions, especially when music professionals started suggesting that I take my almost 4yo dd to a music teacher who lived 5 hours away. I was thinking if she isn't that talented really, then I didn't need to use up so many family resources (time, money, etc...) to nurture her talent but if she was and I didn't nurture her, would I be able to live with that. I found another option but it was a tough few months until we found the option we could live with. For those few months, I agonized over whether or not making certain choices would limit her potential and had a real need to know what her potential was...something no one could possibly know since we don't have any crystal balls.
I have calmed down a lot since then and now have come to see that knowing how gifted my children are doesn't change what I am doing for them schoolwise (though I still don't know whether or not I would pour so much money into her music if she wasn't who she is). I teach each to their ability level...keeping them challenged but not frustrated. I would introduce them to the same things regardless of whether their IQ was 80 or 160 and just teach them as much as they could handle.
I had dd tested but not her older brothers but it was to help me get a handle on where her instructional level was since she was not a sequential learner. Knowing IQ level (potential) didn't help me at all but knowing where she was achievement-wise did give me a starting point and we experimented from there to find something that challenged her. I know where it becomes instructional (that "low simmer" another poster suggested) when she doesn't immediately know it. I tend to ramp things up slowly with her because she tends to be a perfectionist and it is easier not to frustrate her. I have found that providing her lots of options then following her lead has worked wonderfully. She still isn't a sequential learner and is all over the place level-wise but I have become more comfortable with it.
I have worked with children for 15 years...am a physical therapist for an early intervention program. I have learned through that work to never underestimate kids and what they might be capable of doing. I have worked with kids who doctors told parents at birth would never walk and talk who have ended up being ahead of age peers by their second birthday. I treat every child moving toward the next step, whatever that next step might be for them. I am always challenging them to do just slightly more than they thought they could do.
No one lives up to their "full potential." Scientists say that we all use only a minute percentage of our brain's capability. Time restrictions and resource limitations will always cause us to make choices. My goal for my kids is that they have the ability/option to go in whatever direction they chose when they are old enough and mature enough to make that decision. Learning isn't a race to me. They will be able to learn throughout adulthood. As long as they know how to learn and where to find answers, they will do well in whatever field they decide to pursue. In the meantime, I will simply challenge them everyday to do a little more than they thought they could do.