Job Satisfaction - how much is in our genes?

As a career coach, job satisfaction is quite a big deal in my working life. It's my goal to work with my clients to try and find the options that are most likely to give them most job satisfaction, and I guess that running through all my work there has always been an assumption that job satisfaction is based on the interaction between the individual and the situation and is something that can be changed.

I have recently done some rooting around to find out some more about what factors make people happy at work, and have been surprised and a little troubled to find out how much of job satisfaction is based on personality - not match between personality and role, but entirely within the individual, and based on the kinds of personality traits that are, arguably, present at birth. The personality elements that seem to be consistently associated with higher job satisfaction are high extraversion and low neuroticism. And the proportion of job satisfaction that is explained by personality factors may be up to 45%; so not quite as significant as the work factors involved (which I think probably deserve another post all to themselves), but nevertheless pretty important. And this means that there are people who are highly likely to be happy at work and those who are highly likely to find work unsatisfactory, regardless of the specifics of each particular job.

So I have two questions around this. The first is whether I think this feels intuitively right to me. Now I'm very clear that my role as a career coach needs to be informed more by evidence than instinct, but I do struggle a bit when the two really contradict each other. And when I think about my own career history, I can point to jobs that I really loved and those that made me utterly miserable. This of course isn't utterly at odds with the strong influence of personaly, as the research is suggesting that it's just under half of the reason for the level of job satisfaction, but still it makes me question it. Thinking about other people I know, and clients I have had, it begins to ring more true to me. I know people whose levels of contentment with work seem to be pretty consistent, as they move from one job to another.
I wonder what your experience is? Both in terms of yourself and others you know.

Now my other issue is, what do we, as coaches, do about this? If the single biggest factor, and nearly half of the whole concept of job satisfaction is written in the stars, then what impact does this have on our work?
Perhaps this is something that we just ignore? We can't do anything about it, nor can our clients, so what's the point of addressing it, let's just stick to the areas where we might genuinely make a difference? Or might it be something that we share with our clients? Perhaps a clients whose personality makes it more likely that they will be happy at work might be reassured to know this? Or do we just clock it ourselves and use it to inform our practice - ensuring that clients whose personalities are less likely to lead to work satisfaction are clearly encouraged to focus more on the areas that they can control?

I'd love your views!

For more information have a look at Ilies, R. and Judge, T.A. (2003) On the heritability of job satisfaction: the mediating role of personality. The Journal of Applied Psychology 88 750 - 709