While ambidexterity can be learned, most people still gravitate towards performing certain types of tasks with a specific hand. The degree of versatility with each hand is generally the qualitative factor in determining a person's ambidexterity.
In modern times, it is more likely to find people considered ambidextrous who were originally left handed, and learned to be ambidextrous either deliberately or during childhood by indoctrination through institutions such as schools where right-handed habits are often emphasized.