One needs to remember that there was a large history of sexism in employment in the US until the mid-1970s when equal opportunity began to be widely adapted. In WWII there was a large employment of women in various manufacturing industries because men were drafted to fight and there was a need for workers to build planes, tanks, etc. My mother worked in the aircraft industry after graduating from college in 1944. Her employment ceased the day after the peace treaty was signed with Japan ending the hostilities. the same happened to many other women and it was routine for returning soldiers to take their jobs back. For the most part women were consigned to clerical, teaching, and nursing careers from 1945 to about 1975. there were also anti-nepotism regulations that prohibited a husband and wife from holding teaching positions at most universities. One of the lone exceptions were government research facilities which did not have such prohibitions.
Certainly there are more women pursuing STEM careers than was common forty years ago. I think I saw a statistic that there is almost a 50-50 mix in medical school enrollment now. As long as there is equal opportunity things will pretty much even out over the long run. I think there still tends to be a bias against the hiring of women in certain STEM fields. the same thing existed at philharmonic orchestras until they moved to doing blind auditions where the musician was not seen by the listeners. Many more women succeeded in this manner.
I agree with the first paragraph here, and that allowing equality of opportunity is very important.
However, I just don't see a 50/50 split eventually manifesting itself in every field.
Although men and women are technically split in the STEM fields currently in college, like what you mentioned in regards to the medical field, the devil is in the details. (See below to first diagram posted. I choose not to post the article since the author was using this data to support his confirmation bias.)
As you can see, the ratio is about 50/50 overall, but look at engineering and math/computer sciences. These are very high paying fields, but currently many more men choose to study those fields. So the real question is what causes these differences in preferences to manifest themselves in high school (the time when someone decides what to study)? Ability is certainly not it, since girls tend to do better in math then boys in middle school and high school? So it really has to come down to differences in interests. Could it be today that some inherent bias in counselors in high school steer girls away from those subjects? In decades past, maybe, but in the politically correct world of today, I doubt it.
So there is something else at work, and more then likely it is a combination of many things, of which biological differences in gender interests is one of them.
The medical part of the chart I find rather interesting and surprising, and since you brought it up, lets look at that. Clearly it shows many more women studying within that field then men, but what is the break down into subfields. Studying to be a doctor and a nurse are both included in this number, but what is the ratio of male vs. female doctors and male vs. female nurses? It is hard to find the break down of those currently studying to become a nurse, but of working nurses, 91% are female. Since this number will contain nurses from many generations, one can argue that it is skewed high due to previous gender biases. With that said, the study I got this data from found no significant statistical differences in the data for the last 15 years. It has been at the 91% amount for a while now, so one could also argue the trend has plateaued. This means that even though we have been trying to encourage more men to enter nursing, 9% (perhaps 10% will squeak through in a decade) may be the best we can hope for.
For doctors too, the research initially shows a strong bias towards women. 60% of all doctors under 35 are female. However, what about the specialities? Looking at just residencies women were higher in the following: Obstetric & Gynecology (83%), Pediatric (73%), Allergy & Immunology (70%), Medical Genetics (67%) and Dermatology (64%). However, nearly all residencies for surgery are male dominated; Orthopedic Surgery (85% male), Neurological Surgery (82.5%), Thoracic Surgery (73.8%), Vascular Surgery (67%), Plastic Surgery (62%).
Admittedly, burn out tends to effect more female doctors then male, and this could be a gender bias issue within the industry. However, this more then likely would not come into play when a medical student decides on what speciality to study.
So what causes this?
Personally, I don't really see an issue with how the specialities in medical school break down. It still feels like a good fair split overall. However, surgeons tends to make more (I think) or at least get better press, so obviously for the social justice warriors, the fact that women make up a higher percentage in other fields is meaningless.