Answered Jan 20
Possibly a clearer question would be, “Why are a significant portion of female scientists and academics childfree?”
There are three factors.
First, having children is a major distraction (or total derailing) from pursuing higher education.
Second, women who already have the education required to work in science and academia may be filtered out of those pathways after they have children.
Third, women who prioritise this type of career may be aware of the first two points, and therefore adamantly avoid ever having children.
Marriage is also a major issue. Even highly educated women may have their careers severely impaired if they follow a husband’s relocation for his job. That relocation is a strong possibility, since her husband is likely to be highly educated as well.
For Female Scientists, There’s No Good Time to Have Children
Rule No. 1 For Female Academics: Don’t Have A Baby
Fathers and Childless Women in Academia Are 3x More Likely to Get Tenure Than Women With Kids
Another thing that comes to mind is that, scientists, by definition, question things, and try to view things in a rational, organised manner.
Perhaps female scientists are more likely than average to question the pervasive societal message that, all women “should” (or even “have to”) have children.