This piece by Sabine Sardou of Bird & Bird cites women's lack of confidence as a main reason why French women lawyers are not maximising their careers. In arguing this she echoes Sheryl Sandberg's "Lean In" to some extent. Of course it's a generalisation to say women hold back and are passive but, like many generalisations, there's a kernel of true in this point.
I certainly was rather timid in my early career. I had to overcome the conditioning I'd received as a child when I was told girls shouldn't be "pushy" nor be "show offs" and that rewards came to "good girls"; so I assumed all I had to do was keep my head down, work hard, be a good lawyer and I would get full recognition! But my mother had been brought up by her Victorian grandmother and so, naturally, was rather old fashioned. I'm sure today's parents are aware of these pitfalls in bringing up girls and guard against giving such messages. Of course good parenting won't necessarily prevent girls picking up these sorts of messages from the world around them but it is bound to be a major help to daughters to give them positive messages to build their confidence.
If you're a woman lawyer affected by low self-confidence, what can you do? I'm glad to see Mme Sardou suggest women partners help younger women lawyers though I'm not sure I'd recommend women "copy as much as possible men's behaviors" in the workplace as she suggests. Of course mentoring is likely to be very useful in this context. There are also now so many career coaches out there who might be helpful; I've never used one (I don't think they existed when I started out in the profession) but it'd be interesting to hear from women lawyers as to whether they've used coaches and if it was a useful thing to do or not.
Far from minimizing the leading role of the glass ceiling for women in law firms, there are other reasons that explain the current situation and these reasons are not evolving. They are mainly due to women, themselves.