Life is full of risks. Should I invest my savings in the stock market and risk losing everything? If I take up smoking I run the risk of seriously damaging my health. We have to stay constantly alert if we want to stay out of harm's way, something we must also teach our children as they grow.

As parents, one of our most basic instincts is to protect our children. When they are young this is easy enough to do but by the time they've reached their teenage years it is significantly harder to make ourselves heard.

We often hear of car accidents involving young people where speed is sometimes the cause. Is it that young people take greater risks or do they make poorer decisions?

How much risk we are prepared to take, and even how we judge risk in the first instance, are affected by several factors. Unsurprisingly, our brains play a central role.

There are two systems within the brain that have some control over how we analyse risk. The more primitive system is located in the amygdala and is comparatively old in evolutionary terms.

This is the part of the brain that reacts instantly when we are faced with danger. For example, if you have ever sat in your house at night and heard a loud, unexpected, banging noise in another room, you may feel a rush of blood to your heart, your chest feels constricted and your breathing speeds up.

Adrenaline

This is the amygdala kick-starting the release of adrenaline into your bloodstream, triggering the fight-or-flight response.

This kind of instantaneous response works really well -- if you are a lizard or a leopard! The faster you can notice threats and either run away from them or fight back, the more likely you are to live to reproduce.

But our brains have had to adapt to new risks. Some apparently scary things are not as risky as they seem. Other frightening situations are better handled by staying put in order to reduce future risk by managing or dealing with the current risk.

So there is an evolutionary advantage to being able to hold off the fight-or-flight response while you work out a more sophisticated analysis of the situation.

It is this second risk-analysis system that sets us apart from other animals. This analytic, reasoning brain system is located in the neocortex in the frontal lobe area and has developed relatively recently, evolutionarily speaking. It only appears in mammals and is slower to act.

So we have two systems for reacting to risk -- a primitive intuitive system and a more advanced analytic system -- and they are operating at the same time and sometimes in opposition. When they do come into conflict it's hard for the analytic side to overcome instinct, for the neocortex to contradict the amygdala.

For example, those of you who have ever had a fear of the dark will know that despite assurances that no danger lurks in the darkness (neocortex reasoning), the darkness itself still causes anxiety (amygdala instinctual fear reaction).

A lot of the mistakes we make in responding to risks, it seems, are the results of errors that this neocortex reasoning makes.

When we look at the risk judgments of children and teenagers, we see they make even more errors than adults do. This is due to the physical immaturity of their brains. The final part of the brain to completely mature is the frontal lobe area, which doesn't fully develop until our mid-twenties.

Speed

The mistakes we make in judging risks are due to the shortcuts the neocortex uses to speed up its processing of risk. In a rush to analyse the risk of a situation we use rules of thumb known as heuristics.

One such heuristic is that we fear ancient risks more than modern risks. We may fear snakes more than car accidents even though the statistics show many more people will die from road traffic accidents than will die from snake bites.

So those risks that have been with us for hundreds of millions of years are more hard-wired in our brains than risks that have only been present for a hundred years or less.

Another heuristic, or bias, that might affect this is that we aren't afraid enough of those risks that we think we are in control of. This is particularly relevant for teens.

So, because we have control of steering, acceleration and braking, we believe that cars are less likely to do damage to us than snakes.

If you have ever been a passenger in a car that veers towards a ditch or an oncoming car the fright you get is greater, usually, than the fright that the driver gets because they have the capacity to affect what happens.

We fear the risks that others might pose to us because of their malevolence or negligence more than we fear the risks we pose to ourselves by things like smoking or obesity.

A third heuristic is that we fear spectacular but unlikely dangers more than everyday dangers. For example, all parents worry about harm coming to their children. The exaggerated fear of child abduction that followed the saturated coverage of Madeleine McCann's disappearance is a good example of this spectacular but unlikely danger bias.

Harmed

All of the data, gathered over years, shows that children are more likely to be abused by a relative or someone known to them than by a stranger. Despite this, most parents still believe that their child is at greater risk of being harmed by a stranger.

A fourth heuristic is that we fear immediate consequences more than long-term consequences. A teenager who decides to smoke will be more worried about getting caught by their parents and punished for smoking, than they will of dying of lung cancer.

Other things we know about risk are that our risk thermostats vary. Some people will be prepared to accept a higher level of risk than others in the same circumstances.

Our risk thermostat stays stable throughout our lives. One study in the US showed, however, that the presence or absence of peers can change our tolerance to risk.

It measured the level of risk that a group of older teenagers and a group of adults were prepared to take while driving in a car simulator. Specifically they examined whether the participants decided to drive through an amber traffic light or not.

When they then retested all of the adult and teenage participants on the same route, but with friends in the car simulator as well, they found that more teenagers drove through the amber light than they had initially.

Adults, on the other hand, stayed stable (with or without friends present they maintained the same level of risk in their driving). This suggests that teenagers will take more risks when their friends are around.

The emotions of fear and anger bias our risk judgments in opposite directions. Anger leads us to underestimate risks and fear leads us to overestimate risks.

When we are angry, for example if we are in a fit of road rage after being cut off by another driver, we may attempt dangerous manoeuvres such as overtaking, that put ourselves or others in danger. By contrast, most of us moderate our speed (at least for a while) after witnessing the aftermath of a road accident.

What is abundantly clear is that we all make mistakes when trying to judge risk but age has a significant role to play. This is evidenced by the fact that adults tend to make fewer errors because our brains are more mature and more practised at making these judgments. We also take less risk in the company of our peers than teenagers will.

When it comes to the risks that teenage drivers are prepared to take, there are more factors at play than telling them to slow down. We must try to influence the decisions that teenagers will make, especially in dangerous situations.

However, influencing their decisions is a delicate tightrope walk. If there is too little interference from us they get exposed to unnecessary risks. If there is too much interference our advice gets rejected out of hand.

In next month's feature I will look more closely at decision-making, in the context of what we now know about risk, to see how we can best influence our children and teenagers.

By teaching them the skills of decision-making we give them a vital tool for keeping themselves and others safe.

- David Coleman

Irish Independent