what factual evidence would you like to see? I've read lots of books regarding the topic, talked to experts etc. I'd like to give you more information but unfortunately, there are not many Internet websites regarding the topic of converted handedness in English. My opening post was a brief summary of all the knowledge I have gathered throughout the years to give people a nice overview about the topic. What exactly would you like to get more information about?
Here's a website, that explains the problems about a converted handedness: http://www.linkshaender-beratung.de/english/Problem.htm
Hey there, BraveNewWorld,
what I meant by "Ambidextrousness doesn't exist" is that every person has a dominant hand. This doesn't mean that it's impossible to get good at something with your non-dominant hand. But using your non-dominant hand for activities requires a lot more energy. In fact, writing with your non-dominant hand requires up to 30% more of your energy, than when writing with your dominant hand, which eventually leads to exhaustion and other consequences I listed above.
Other things you do with your non-dominant hand may not have such severe consequences but it still is more energy consuming than when you use your dominant hand.