Things took a turn for the tumultuous in Europe last week. Excitement peaked with simultaneous public outbursts when London pipped Paris at the post to host the 2012 Olympics. In the run-up to that decision, people had enjoyed the feel-good, make-poverty-history partying linked to the Live 8 concerts and the Group of Eight's new plans for Africa. A day later came the emotionally numbing bomb attacks in London. Within hours, tens of millions of people on one side of the channel were wrenched from elation to horror and, on the other, millions more were thrown from loathing to empathy. Why were Parisians so demonstrably disappointed and Londoners quite so ecstatic? Their heightened emotions were linked to the traditional rivalry between Paris and London, recently fuelled by contrasting economic climates and by opposing positions on Iraq. The scenes were a tamer version of the outrage expressed by Chinese mainland football fans when their team lost in the Asian Cup final last summer to Japan. In that case, a traditional rivalry was ostensibly aggravated by unrepented wartime abuses, prejudiced textbooks and a reported orgy involving Japanese men and Chinese prostitutes. But that account, seized on and perpetuated by the media's lower orders, is not particularly convincing. Rivalries are more complex than that. If humiliation and war abuses were all that it took to stir up adversarial emotions, then why do the French get along with their wartime adversaries, the Germans, while their British liberators get right up their nose? As for the tears, kisses and general absence of aloofness in London when the Olympic announcement was made, that relates to a national trend, and debate, that began in the late Princess Diana's days. Mass delight is no longer condemned. But cheering over winning something is a different matter. It evokes a worrying sort of happiness: the kind that is at someone else's expense and can end in a riot. It is true that emotions in crowds can be amplified through responsibility-reducing anonymity and a feeling of membership - but this is only for those emotions people joined the crowd to share. Diana's influence seems to have unleashed a stiff-upper-lip backlash - we've gone over the top. In this view, minutes of silence set aside for bomb victims are signs of 'compassion inflation'. Armbands and rallies against poverty are hollow displays. 'We live in a post-emotional age,' writes Patrick West in a report for the independent think-tank Civitas. People should show compassion by giving to charity instead of pointlessly adding to piles of 'damp teddies and rotting flowers', he said. In fact, there is genuine feeling in all those things. The occasions may be staged, but that does not mean the feelings that accompany them are entirely false. What looks like hollowness is the complicated, surrogate nature of shared emotion. We do not cheer or cry for a single reason, but for both superficial and profound reasons, public and private - many of which remain unclear even to ourselves. There are the flashy emotions like joy, anger and grief. But they are underpinned by others: loss, fear, regret, pride, disillusionment, relief, frustration, guilt, identification and sorrow. Why shouldn't people benefit from such occasions to get all that off their chests? The British are now beating their chests in defiance while the French are going through the hand-wringing stage. But they will soon settle back into trading insults about bad British food and bad French manners. Your rivals, it is useful to recall, reflect on you as much as do your friends: both should be worthy of you. Jean Nicol looks at everyday issues from the point of view of a psychologist everydaypsychologist@yahoo.com