Skills are Built By the Degree
The higher the tertiary entry scores needed for a course, the better the abilities of first-year students in such skills as critical thinking, problem solving and communication. The same is true of students as they finish their courses, only more so.
It turns out that the medicos enter and emerge uni with the best problem solving skills (not surprising given that the entry UAI for medicine was an intimidating 99.75 last year and they exit the course after 6 years in uni, with 3 degrees). Combined law is perhaps the next largest bunch (99.30-99.40 entry), but law grads are edged out by their science/eng counterparts (~90 entry). I would think this is due more to the content of the course – engineering is pretty tough and the hours are long. Law from what I hear can be pretty cruisy (I think first year engineers have almost double the hours of everyone else) so it’s probably because they are the top 0.7% of the population that they are naturally intelligent, than the content of the course. It also explains why strat consultancies love doctors and engineers (especially chemical engineers, who for some reason seem to be in every consulting firm).