30/06/2014 07:22 BST | Updated 27/08/2014 06:59 BST

Another Woman Makes it to the Board - But Many More Still Need Quotas to Get There

The day when appointing a woman to the board of a FTSE 100 company does not make headlines will be the one to really welcome. But it would be churlish not to applaud the news that mining giant Glencore has, finally, ended the ignominy of being the only top UK company without a female director.

But before we string out the bunting it is worth noting that the arrival of Patrice Merrin to the top table is in a non-executive role. In other words, one without real power or responsibility.

We need temporary quotas to complete the job of giving women a fair chance, and no amount of non-executive roles should become an excuse for denying decision-making authority on the basis of gender. There is also something mildly unsettling about the suggestion that it took Glencore six months to find a suitable woman. Really?

Business Secretary Vince Cable has consistently committed himself to board diversity, but it was a stretch for him to describe the Glencore appointment as historic. Necessary, yes. Overdue, certainly. But historic? In truth, not enough is changing to warrant such a claim.

Whilst certainly progress, it is not ever going to be enough simply consigning women to the second tier of corporate significance. In fact, the representation of women holding executive board positions has actually fallen; and just eight women are chief executives of FTSE 250 companies.

On the same day that Glencore was mildly improving a dismal record it emerged that only seven per cent of funds are run by women. This is simply not acceptable or even sound business sense.

As Bestinvest, the wealth management firm that commissioned the research, noted: This is particularly puzzling as female fund managers have consistently outperformed their male rivals over their careers.

The truth is that women still face huge obstacles to professional advancement. Few people can now genuinely believe that women are not qualified or committed. But there is what psychologists describe as 'unconscious bias' governing a behaviour which is proving a drag on equality.

This bias is part of our social identity. Acknowledged or not, we are all 'hard-wired' to respond positively to people similar to ourselves, and react against those deemed different or a threat. In the workplace, this unconscious bias can stop us from hiring the best person for a vacancy, damage client relationships, increase staff turnover and lead to legal claims.

I have routinely had to challenge decisions made about the careers of women which have been based on assumptions about their life choices, not evidence.

There is also a kind of professional apartheid, Women are allowed - by men - dominance of the so-called 'soft skills', such as human resources, marketing. But they are resisted, even criticised, when they demonstrate the sort of tough, ruthless, clear-minded thinking that men value in each other.

Two significant steps need to be taken to deal with unconscious bias. The first is the introduction of quotas to force boards, executive recruitment agencies and, regrettably, some women, to tackle the problem. This will create a level playing field. Critics say that quotas are demeaning and distorting. They are not and will jump-start change. There are plenty of able women to select, and quotas will encourage firms to bring on female talent.

The second step is training. Even the BBC recently sent senior journalists on a course to stamp out unconscious bias and encourage diversity.

We are not near dealing with unconscious bias, let alone welcoming anything historic. Until we level the playing field with temporary quotas women making it to boards is still going to make the news. We need it to pass almost unnoticed for the job to be done.