Terrorism doesn’t begin and end with the terrorist. The act itself is only the start, and requires a contribution from us, its targets, to have maximum effect. We keep our side of this unwitting bargain in three ways. We react with fear (a natural response that’s hard to avoid). We take that fear out on others we regard as slightly less human than ourselves (a move that may be tempting but is within our power to reject). And ultimately, we change the way we organise our society (ditto).

Air France bomb scare on plane to Paris was a false alarm, says chief executive Read more

Because of Paris, San Bernardino and the continual threats made by so-called Islamic State, we are on high alert – and not just government officials and the police. Our brains are primed to wonder if that rucksack in the corner of the train is a bomb, rather than exactly what you’d to expect see on public transport. That man at the airport, sweating. Is he nervous because he’s scared of flying, or about to carry out an attack? It’s at times like this that we desperately need to be realistic, not give in to our worst fears.

Why? At the very least, reminding yourself that terrorism is extremely unusual will help you feel a bit more relaxed about the day ahead. It might also stop you making totally innocent people feel threatened or hated, like the Muslim man forced off a train because he was using his iPad “suspiciously”. So, here we go: even if the horrific attacks of 7 July 2005 were repeated every year, as a Briton you’d still be roughly as likely to be struck by lightning as killed by terrorists.

Opportunists will take advantage of jitteriness to make a bigger impact

There’s another important reason to keep things in perspective. Opportunists will take advantage of jitteriness to make a bigger impact. Thankfully, there are more hoaxers and attention-seekers in the world than there are homicidal fanatics. But their actions aren’t insignificant. Last week in Los Angeles, 1,000 schools attended by 640,000 pupils were shut after someone emailed a threat to use “explosive devices” against them. Yesterday an Air France plane made an unscheduled landing after a suspect package was found in a toilet. Images purported to be of the package were shared online. It looked almost too bomb-like to be true: a Mission Impossible version of the real thing. Within hours it was shown to be a harmless fake.

Is there any other way to react? No one in their right minds would suggest that the pilot, faced with a situation like that, should blithely carry on and hope for the best. He did what he had to do. But Kenya’s airport authority referred in their initial statement to a “bomb” rather than a suspect package, and this was quickly shared as fact. One editor used block capitals to spread the news: “#BREAKING: Picture of the BOMB found onboard #AirFrance plane that landed in #Kenya”. It was retweeted 115 times. The obvious lesson is that officials, journalists and social media users need to handle possible terrorist incidents with extreme care. As we’ve already seen, terrorism is very unusual – but bomb scares and panics are common.

And as far as the school closures go, it’s worth noting that the New York school district received a similar threat on the same day. Police opened an urgent investigation but decided not to close a single school. Asked to comment on the response by Los Angeles law enforcement, New York’s police commissioner, William J Bratton, said: “I think it was a significant overreaction.”

Terrorism is real, and most people would rather be cautious than fall victim to it. But there are two problems with that. First, there’s caution and there’s paranoia. Cass Sunstein, a former aide to Barack Obama, has written that the tendency of those not directly affected to overreact to terrorism is the result of “probability neglect”. We “focus on the badness of the outcome, rather than the probability that the outcome will occur,” which we know to be very small. He goes on to argue that terrorists have “working knowledge” of probability neglect – they manipulate our exaggerated fears in order to change our behaviour.

Second, the harm that a climate of suspicion does to our society is really not worth the minimal extra protection it might bring. It creates fear, resentment and alienation, which can in turn contribute to the risk of radicalisation. It brings out our worst, rather than our best selves, making us less willing to welcome people fleeing war. It damages our way of life at a fundamental level, and this damage is exactly what terrorists desire.

In short, terrorists need our help: do you really want to lend a hand?