[anon4]

A few ideas come to mind

-1- Women have a lower salary, therefore their anchoring point is lower.

-2- There are few women in the department, therefore every woman feels threatened by every female applicant - they are fighting for a scarce resource.

-3- The push against sexism has resulted in men overvaluing women, while women themselves have no qualms about rating other women exactly what they think they are worth (which might still be less than they should, see 1).

-4- There may be a strong correlation in women who can succeed in a male-dominated environment for sociopathic psychological traits.

-5- There may very well be correlation (though no direct causation) between gender and expected performance, which combined with 3, results in women applying an unconscious bias.

Basically, you do not have an unbiased sample and can't make generalisations from just that article.