Key point: for decades in the UK, school education forked at age 16 -- the point at which you specialized. Prior to age 16 you'd be studying for exams in 6-10 subjects: originally 'O' (ordinary) levels, then GCSEs. (School leaving age was 16.) If you wanted to continue and eventually go to university, you then went on to study for 2 years for 'A' (advanced) level exams -- roughly equivalent to year 1 or 2 at a US university. (British taught university degrees were typically 3 year courses.) However, this was intensive enough that typically you'd only take 3 or 4 'A' level subjects. This forced early specialization -- dropping either all science or all arts subjects.
(This system ran from the late 1940s through the 1990s, subject to fine-tuning. So, for example, in 1981-83 I was taking four 'A' level subjects: physics, chemistry, biology, and 'general studies' (a vague attempt to shoe-horn the entirety of the liberal arts field into one quarter of the student's time).)
(This system ran from the late 1940s through the 1990s, subject to fine-tuning. So, for example, in 1981-83 I was taking four 'A' level subjects: physics, chemistry, biology, and 'general studies' (a vague attempt to shoe-horn the entirety of the liberal arts field into one quarter of the student's time).)