ON this date in 1950, North Korea invaded South Korea, starting what we call the Korean War. Some 67 years on, the two countries remain divided and tensions are higher that they have been for several years. Many people’s automatic reaction is that we, as a species, are condemned to repeat the past. Even the great English historian AJP Taylor once said that history was “just one damned thing after another”.

However, Taylor was also wise enough on another occasion to say: “Nothing is inevitable until it happens.”

These are examples of the mind’s tendency to try to see order in life, especially with regard to suffering. The great ancient religions and philosophies of India called it karma, the idea that there is a natural law which dictates that our intentions or actions have results that will either haunt or reward us at some point in the future.

I’m not a believer in karma but it’s a basic law of physics that every action will cause reactions of one sort or another. We also know that our emotions or human activities often result in ripples that affect the people around us. At a neuroscience level, the concept of neuroplasticity dictates that our minds are constantly being shaped, moulded and remoulded by our experiences, which in effect is just another example of cause and effect: karma of sorts.

There are two issues concerning these points that I’d like to explore. The first is some people’s tendency over time to see things in a pessimistic light or indeed to get irritated more easily. Think of the “grumpy old man” stereotype. The other is the potential for us to gain an increasing degree of control over how our minds are shaped by external events and our reactions to these.

I have a sense that negative experiences weigh more heavily than positive ones. I can’t see much research on this matter, maybe because it is difficult to measure the impact of one event against another. But there are some obvious major life examples which can make the point. Consider a wedding, or the birth of a daughter or son: events many people describe as the happiest of their lives. Then consider something awful: being diagnosed with cancer or losing a loved one, for example. Feel how they weigh on your mind, or in your heart. A wedding or a birth may be special but the excitement and joy tend to lose their shine with the everyday realities of marriage or bringing up children. We may still love our spouse or children dearly, and look back on our wedding and the birth with nostalgic pleasure but over time these events don’t remain on our minds as a day to day presence.

However the sense of having had cancer, and the potential for it to recur, or the lifelong sadness that follows the loss of those we love, do continue to weigh on our minds, and often affect the tone of our day to day lives. So I believe negative emotions are, if you like, heavier in feel and effect than positive ones, and they hang around for a much longer time. Over the years therefore we can become increasingly filled with the effect of these negative experiences, whereas the lighter happy ones seem to arise then dwindle from our minds. As a result, an increasingly negative version of who we are dominates.

Which brings me to my second point. We can deliberately use the brain’s neuroplastic quality to help ensure that we don’t suffer from this tendency to become more negative or pessimistic as we get older. Because our mind tends to consolidate and strengthen our negative views and habits over time we must deliberately and continuously combat that tendency.

There are many simple ways of doing this. As is explained every week by my fellow column writers in the Sunday Herald Magazine, fitness and exercise, eating healthily, and simply getting outdoors more often, have a positive effect not only on our body but on our state of mind. So take their advice seriously and do what you know is good for you, while reducing what is not.

Mindfulness is, however, the most direct and powerful way we can combat our tendency to see life through a dark lens. Research by neuroscientists, psychologists and doctors over the past 30 years has shown that mindfulness practices as simple as noticing what it is actually like to feel and taste a piece of fruit, fully, slowly and in a savouring way, does combat those negative mental tendencies. Regular and ongoing attention paid to any experience of the five senses, or indeed of the mind and its content, can reverse much of the mental junk we have accumulated over time. Moreover it can and does replace it with a beautiful combination of fine mental qualities. Clarity of thought. Calmness even when a crisis or argument occurs. Contentment and love of being alive. Compassion and consideration for others, and not just humans, but animals, the environment, everything that is part of the natural world.

It is hard to overstate how good these qualities are in making your life more meaningful and more enjoyable. It does not deny, nor ignore the horrors of life, human and natural, but it does free us from the delusion that everything is worse than it used to be, and instead remind us that so very much is miles better than what we had in the past.