An important factor in the spread of the Empire was the adoption of a meritocracy, with promotion based primarily on intelligence, education and achievement, not accidents of birth. Ironically, this was done almost accidentally; there was no easy way to merge the diverse governments of the Empire using any of the existing systems, and the USA in particular stood firmly against inherited titles and position. Basing rank on education and attainment seemed a good way to pay lip-service to these ideals, while in fact giving the entrenched aristocracy a significant advantage.
It was assumed that those in power would inevitably be a product of the most expensive and prestigious education, which was of course most readily available to the wealthy and powerful. But the traditional schools and colleges emphasised dead languages and other subjects which had little or no relevance to the rapid advances in technology of the time. The next generation of rulers came from backgrounds such as the grammar schools and technical colleges of Britain, the few institutions that emphasised science such as Imperial College in London, and of course from similar institutions in Germany and the USA; most of the Empire’s rulers since the beginning of the 21st century have had scientific or engineering qualifications. Of course there are still barriers to advancement; the poor can rarely afford the years of education (and accompanying expenses) needed to rise in the hierarchy of government, and there are a dozen applicants for every worthwhile scholarship. As usual, the advantages are mostly with the rich.
That's a bit vague on the American and German equivalents - any suggestions that were around from say the 1920s onward that I can insert reasonably easily?
Grammar Schools - 11-18, offered a broader curriculum than e.g. public schools.
Technical Colleges - 16+, aimed at working men in engineering, science, etc.
Imperial College - the first university in the UK to emphasise science over the classics etc.