Summer is coming – does that mean brighter moods ahead?

The changing of the seasons from winter to spring and from spring to summer instinctively incites excitement. Longer evenings are always celebrated; sunshine and warmth is dubbed ‘good weather’. But does the sun actually make us happier?

I wondered if, to a certain extent, Irish people have been conditioned to believe a certain type of weather is inherently better. Right from childhood, we’re hardwired to associate summer with time off school, playing outdoors and holidays. And this partiality is right there in the language we use – happy people are said to be of a ‘sunny disposition’; moody people are ‘gloomy’, evoking images of darkened clouds.

“We’re more likely as human beings to recollect and have nostalgia for times that were memorable and not the humdrum of daily living,” says Dr Malie Coyne, clinical psychologist and author. “So, obviously, summertime is a more memorable time for children because it’s more fun and it’s not the everyday of school.”

The psychology of association is undeniably powerful, and there’s more to the science that explains our enthusiasm for the summer. Sunlight helps the body to produce more vitamin D, which raises energy levels and strengthens bones and muscles. Various studies have also linked sunshine to higher levels of serotonin, a neurotransmitter linked to mood regulation. A break in wind and rain generally allows for more exercise, too, which brings its own health and wellness benefits.

Research also shows that people behave more altruistically on sunny days than cloudy days. Even stock market returns are higher than on days when it’s overcast.

(As an aside, I’ve always thought it a happy development that, on this side of the world, Christmas falls in the dead of winter, illuminating what would otherwise be a dark period of the calendar.)

With sunshine seemingly acting as some kind of wellness tonic, you’d expect nations with the hottest climates to automatically be the cheeriest. In fact, the happiest country in the world is reportedly Finland, with four more Nordic nations also in the top 10. Obviously, there’s more going on in that part of the world than just the weather. In the OECD’s Better Life Index, Finland outperforms the average country across categories such as education, work-life balance, environment and safety. And so, the sun’s mood-enhancing abilities must be gauged in relative terms.

The dark side of the sun

Hot weather can have negative effects on human behaviour too. In the 1990s, the ‘heat hypothesis’ was coined to explain why violent crime rates rise in the summer. In the US, for example, the murder rate rises by about 2.7% during this season.

Researchers theorised that because heat makes us feel physically uncomfortable, we’re more inclined to aggressive thoughts and negative interpretations. (But what also must be considered when interpreting these numbers is that people are outside of their homes more during summer, and so unplanned violent altercations are more frequent.)

Additionally, a Swiss study found that an increase in temperature can negatively affect mental health and increase hospitalisation for those with mental disorders such as bipolar disorder, anxiety, depression and schizophrenia.

“People with bipolar disorder would feel overexcited during hot days,” explains Ana Maria Vicedo-Cabrera, one of the researchers. “These kinds of patients, they have a different way to react to the changes in temperature. And this could potentially affect, or be a driver, for them to be admitted into a hospital, or a sign that the condition is getting worse.”

The study acknowledges the various factors impacted by rising temperatures. For example, some medications can disrupt the body’s thermoregulation, and this can be exacerbated in hot weather, while dehydration can result in lower serotonin levels.

There can even be negative impacts from the uptick in social interaction in summer, when there can be more invites to meet up. This can be a stressful time for those with fear and anxiety around social situations, increasing the pressure to comply. “For these patients that had schizophrenia, depression, etc, the fact that the weather is better, and seeing that people are happier, this can create some frustration, and that’s why they would feel even worse,” says Ana Maria.

For certain, the disparity between summer and winter is evident in human behaviour, for reasons that are both biological and influenced by the warp and weft of our social fabric.

There are plenty of good reasons to believe that getting a bit of sun during the precious little time we have with it in Ireland is a positive thing. But when it comes to wellness, your mood is not entirely at the mercy of the weather report. The best strategy, evidently, is to tailor your life based on your own personal temperament, feelings towards the weather, and your own environment.

Learn to find a sense of calm, whatever the weather, with our Introduction to Meditation, a live workshop on 16 May 2024.