Certain drivers are considered to be particularly intelligent in their on-track decision-making; on the current grid, I would name Schumacher, Button and Vettel. This is a factor independent of their purely physical ability in driving the car. Furthermore, there is an obvious relationship between driver intelligence and the ability to maximise a car's performance through testing, relationship with engineers etc.
However, I think that intelligence in an F1 driver also redounds to his success in a more general way. If we accept that intelligence plays in a role in how able a driver is to moderate his responses to media pressure and to appraise in a realistic manner the way in which the mass media work, then intelligent drivers should seem to deal better with off-track problems. And intelligence goes hand in hand with an ability to establish mature and ultimately profitable relationships with political figures in F1, as well as the other drivers.
Consider last season: both Vettel and Schumacher came under media fire, Vettel for his relationship to and crash with Mark Webber, and other racing incidents; Schumacher for being generally off the pace in his return to F1 and for his incident with Barrichello and the wall in Hungary.
Here is Vettel's interview after Turkey 2010:
"I'm not the kind of guy to push all the blame on one person" - seems a generous attitude, and deflects attention from the question of his own responsibility for the incident.
Emphasises the harm done to the team, framing the incident as merely a negative outcome for himself and his team, rather than a confrontation between himself and Webber coming to a head
No sheepish expression, just looks displeased.
Dismissive nod towards the media at the end as though as to say, "Run along now."
I can't find Schumacher's interview after Hungary 2010, but I remember that he basically said that Barrichello talks a lot of nonsense, and like Vettel showed no submissive or resentful body language. Also, despite regularly dismal weekends for the first two thirds of last season, I never once heard him admit that he had been slow, or make a negative comment about his and his team's prospects for the next race. Eventually the media got tired of picking on him, since he wasn't crumbling under their pressure, and have been fairly positive towards him in general since Suzuka last year.
When Vettel was unhappy with Alonso's defensive tactics in Monza, he brought up the issue in the press conference and beforehand to Alonso, whilst framing it as "nothing serious". Alonso therefore knows that Vettel will be unhappy with similar moves in future, but that Vettel will keep his cool if Alonso does pull an unfair move and not harm his image with the media or the stewards, or his chances in the race, by doing or saying something rash - a good reason to race fairly with Vettel. Contrastingly, when Lewis is unhappy with someone's defending he complains immediately about it over the radio and then either fails to control himself before the media and comes across as an impotent whiner (Monaco) or is passive-aggressive and comes across as someone who can be trampled upon (Monza interview - where he was clearly unhappy with Michael's blocking but pretended not to be).
There are other options beside these emotionally immature extremes (a point that some Lewis fans have missed). For example in Monaco he could have stayed calm, made simple reference to Massa's "very hard defending" and suggested that "some" drivers need to look in their mirrors more often. He could then have said without being prompted that he looks forward to the next race where he thinks McLaren will be fast. If asked if he felt he was to blame for anything, he should have said that that is for the stewards to decide, but in his opinion it was normal racing. If he kept that up, soon enough the media would lose interest and pick on a more vulnerable target.
Whether or not any of these drivers was at fault or not, or had a legitimate grievance in any circumstances is irrelevant and need not be discussed. The point I am making is that Lewis's intelligence in his handling of the media leaves much to be desired, and it is this (rather than as some have suggested, his overtaking ability [!] or his ethnicity) that causes them to prey on him. The media likes nothing better than a fallen idol, and Lewis can continue to fall for a long time before they think about leaving him alone - even if his results improve - until such a time as he learns how to deal with them in the same way that the German drivers do.
If we generalise this lack of political nouse to his dealings with officials and other drivers, it is not hard to imagine how he has allowed himself to become the stewards' whipping boy and in this season alone Massa's and Maldonado's worst enemy (remember also that in 2008 he had Alonso vowing to help Massa win the title at all costs - might he not have smoothed their relationship at all?) If he can't make them like him, they should at least fear the consequences, or feel that it is futile to criticise him publicly (so we see that this issue is also intimately related to Lewis's media image). If they didn't think there was anything to gain by picking on Lewis, they wouldn't do so.
Just my two cents on the Lewis question!