So, are all such attempts doomed to failure? If new words as varied and inconsequential as jeggings, upcycling, bromance and mankini can be readily accepted, why not new pronouns? Clearly these terms haven't entered standard usage, but there has been an increase (at least, anecdotally and in my own experience) in attempts at gender neutrality through s/he, he or she and the use of they.
Perhaps these words are harder to change because they are so common. Research a few years ago suggested that our most commonly used words are the most resistant to change, despite often being the most irregular. So, while we're happy to adopt jeggings as a word (although the day I wear the actual clothing is the day I die) but slow to adapt our pronoun use.
Perhaps we should all just give up and accept that English was historically built by men, written by men and is probably destined to reflect an imbalance that favours men? Perhaps not.
While prescriptivists will no doubt cry that changing or inventing pronouns to avoid gender bias is "PC gone mad", and pedants will argue that the current best-placed alternative they shouldn't be used for singular subjects (because it's always been a plural pronoun), we know from academic research that gendered terms (including pronouns) do matter.
Words have a huge impact on how gender is constructed and words can often hold the key to how we define ourselves in so many different ways. Just have a look at a catalogue for children's toys and how gender roles are not only differentiated by colours and activities but by words and phrases.Then have a look at this piece of research from 1972:
In 1972… some three hundred college students were asked to select from magazines and newspapers a variety of pictures that would appropriately illustrate the different chapters of a sociology textbook being prepared for publication. Half the students were assigned chapter headings like “Social Man”, “Industrial Man”, and “Political Man”. The other half was given different but corresponding headings like “Society”, “Industrial Life”, and “Political Behavior”. Analysis of the pictures selected revealed that in the minds of students of both sexes use of the word man evoked, to a statistically significant degree, images of males only — filtering out recognition of women’s participation in these major areas of life — whereas the corresponding headings without man evoked images of both males and females…. The authors concluded, “This is rather convincing evidence that when you use the word man generically, people do tend to think male, and tend not to think female” ([Miller et al. 1980, pages 19-20], quoted by Spertus; emphasis added).
(source: http://jerz.setonhill.edu/writing/grammar-and-syntax/gender-neutral-language/ )
Swift and Miller (referred to both in the first paragraph and in this quote) later went on to write their influential Handbook of Non-Sexist Writing which played a significant part in drawing attention to the systematic derogation (or outright denial of the existence) of women in some aspects of language. But in an earlier book, Words and Women, they set out to - in the words of Swift in this illuminating interview with the writers - draw attention to the imbalance in language:
All we wanted to do was to point out to people that ours was a male-centered language. We all have this male-imposed view when we first acquire language, and it gets reinforced in the recess of using language. We wanted people to think about this and then try to come up with their own ways of solving the problem. There is no set solution such as every 'man' should become 'person,' so we refused to make this a how-to-do-it book.
When it was released, it garnered favourable reviews and in the words of Benjamin DeMott of the New York Times was...
...a complacency shaker. It convinces you, if you need convincing, that belief in the inconsequentiality of many of the customs and conventions under examination is, in fact a species of complicity in the continual humiliation of half of the human world.
So, why come back to this 2012? Hen, that's why. Swedish writers have now taken up the cause and produced their own new gender neutral pronoun, hen, which is explained in this Slate article. There's an interesting take on it from this blogger too, who argues that "It is simply another form of domination and since it lacks substantial support among grass roots it will not succeed".
Will hen catch on as thon, hesh, hir, tem, tey and ter failed to? God knows and hesh ain't letting on yet.