Definitely not going to trawl through a tonne of threads looking for evidence. I have found this: https://pubmed.ncbi.nlm.nih.gov/33273109/
Conclusions: Students attending a medical school with greater academic performance and research focus are more likely to apply and subsequently embark on a clinical-academic career. However, students wishing to embark a clinical-academic career from any medical school have an equal chance of success.
This, which is specifically about surgery: https://publishing.rcseng.ac.uk/doi/10.1308/rcsbull.2018.90#sec-4
Conclusions: It is incumbent on the current generation of surgeons and educators to understand what factors influence students’ career choices, and to focus their attention on addressing the underlying issues that may dissuade students from aspiring to a surgical career. Without concentrating on these important points, surgical recruitment may continue to falter, jeopardising our supply of future talent.This study illustrates that the choice of medical school affects a student’s likelihood of becoming a surgeon. The next step is to understand what it is that institutions producing large numbers of surgeons are doing differently, in order to reduce any inequalities in experience that may exist between medical schools.
And finally this: https://pmejournal.org/articles/10.1007/S40037-020-00636-7
Results Three overarching themes emerged from the analysis: The ‘influence of medical school’, ‘perceived suitability to specialty’ and ‘belonging and fitting in’. A thematic map captured the participants’ perceptions on why their preferences had changed, with major influences echoing existing research. However, novel findings included participants’ personalities and enthusiasm changing over time, the need for a ‘sense of belonging’ and participants defining the term ‘variety’ uniquely, perceiving their current specialty preference to match their definition.
Discussion This was an original, in-depth study on changing career preferences, which is an ill-defined subject within the literature. Analysis revealed preferences changed for a variety of medical school, personal and specialty reasons, leading to the construction of an updated model of medical career decision-making. Medical career preference remains a dynamic and ever-evolving phenomenon, influenced by an intricate interplay of internal and external factors. An understanding of this is crucial for future workforce planning.
So unless someone has access to robust data, I am going to conclude that medical careers can be influenced by the individual, and are not entirely pre-determined by GCSE results, A Level choices or medical school....