Nature v. Nurture

It's an old debate. A friend and colleague was told by a trainer yesterday that only 5% of what we are results from our genes, for the rest "everything is re-wirable". But I disagree: it is possible that Leonardo da Vinci COULD have been 95% NOT a genius, if he had been "re-wired" by a different upbringing and education, but it seems to me that circumstances would have had to have been pretty dire to repress his abilities to that extent. Certainly human beings are adaptable, but I do not believe fundamental things like sexual orientation and basic character traits can be altered, even if they could be driven underground, or expressed in different ways depending on the opportunities/obstacles encountered in life.

Of course, a trainer probably has to take such a view, after all, he was trying to persuade people that they could learn different ways of reacting in specific circumstances. And as regards the skills we acquire in life, of course these are learned and not inherited, even if we must be "hot-wired" for language-acquisition (but some more "hotly wired" than others?) and some other basic abilities needed to acquire these skills. I do believe education ought to include as much as possible a search for the various gifts an individual might possess, but which are not quite strong enough to emerge of their own accord: who knows how many individuals with musical ability, who have never had the chance to discover it, die with the music still in them?